diff options
Diffstat (limited to 'drivers/spi')
| -rw-r--r-- | drivers/spi/Kconfig | 20 | ||||
| -rw-r--r-- | drivers/spi/Makefile | 2 | ||||
| -rw-r--r-- | drivers/spi/au1550_spi.c | 974 | ||||
| -rw-r--r-- | drivers/spi/spi.c | 33 | ||||
| -rw-r--r-- | drivers/spi/spi_butterfly.c | 83 | ||||
| -rw-r--r-- | drivers/spi/spidev.c | 584 |
6 files changed, 1616 insertions, 80 deletions
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig index 4a012d9acbff..07c587ec71be 100644 --- a/drivers/spi/Kconfig +++ b/drivers/spi/Kconfig @@ -64,6 +64,17 @@ config SPI_BFIN help This is the SPI controller master driver for Blackfin 5xx processor. +config SPI_AU1550 + tristate "Au1550/Au12x0 SPI Controller" + depends on SPI_MASTER && (SOC_AU1550 || SOC_AU1200) && EXPERIMENTAL + select SPI_BITBANG + help + If you say yes to this option, support will be included for the + Au1550 SPI controller (may also work with Au1200,Au1210,Au1250). + + This driver can also be built as a module. If so, the module + will be called au1550_spi. + config SPI_BITBANG tristate "Bitbanging SPI master" depends on SPI_MASTER && EXPERIMENTAL @@ -159,6 +170,15 @@ config SPI_AT25 This driver can also be built as a module. If so, the module will be called at25. +config SPI_SPIDEV + tristate "User mode SPI device driver support" + depends on SPI_MASTER && EXPERIMENTAL + help + This supports user mode SPI protocol drivers. + + Note that this application programming interface is EXPERIMENTAL + and hence SUBJECT TO CHANGE WITHOUT NOTICE while it stabilizes. + # # Add new SPI protocol masters in alphabetical order above this line # diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile index a95ade857a2f..624b6363f490 100644 --- a/drivers/spi/Makefile +++ b/drivers/spi/Makefile @@ -14,6 +14,7 @@ obj-$(CONFIG_SPI_MASTER) += spi.o obj-$(CONFIG_SPI_ATMEL) += atmel_spi.o obj-$(CONFIG_SPI_BFIN) += spi_bfin5xx.o obj-$(CONFIG_SPI_BITBANG) += spi_bitbang.o +obj-$(CONFIG_SPI_AU1550) += au1550_spi.o obj-$(CONFIG_SPI_BUTTERFLY) += spi_butterfly.o obj-$(CONFIG_SPI_IMX) += spi_imx.o obj-$(CONFIG_SPI_PXA2XX) += pxa2xx_spi.o @@ -25,6 +26,7 @@ obj-$(CONFIG_SPI_S3C24XX) += spi_s3c24xx.o # SPI protocol drivers (device/link on bus) obj-$(CONFIG_SPI_AT25) += at25.o +obj-$(CONFIG_SPI_SPIDEV) += spidev.o # ... add above this line ... # SPI slave controller drivers (upstream link) diff --git a/drivers/spi/au1550_spi.c b/drivers/spi/au1550_spi.c new file mode 100644 index 000000000000..ae2b1af0dba4 --- /dev/null +++ b/drivers/spi/au1550_spi.c @@ -0,0 +1,974 @@ +/* + * au1550_spi.c - au1550 psc spi controller driver + * may work also with au1200, au1210, au1250 + * will not work on au1000, au1100 and au1500 (no full spi controller there) + * + * Copyright (c) 2006 ATRON electronic GmbH + * Author: Jan Nikitenko <jan.nikitenko@gmail.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/errno.h> +#include <linux/device.h> +#include <linux/platform_device.h> +#include <linux/spi/spi.h> +#include <linux/spi/spi_bitbang.h> +#include <linux/dma-mapping.h> +#include <linux/completion.h> +#include <asm/mach-au1x00/au1000.h> +#include <asm/mach-au1x00/au1xxx_psc.h> +#include <asm/mach-au1x00/au1xxx_dbdma.h> + +#include <asm/mach-au1x00/au1550_spi.h> + +static unsigned usedma = 1; +module_param(usedma, uint, 0644); + +/* +#define AU1550_SPI_DEBUG_LOOPBACK +*/ + + +#define AU1550_SPI_DBDMA_DESCRIPTORS 1 +#define AU1550_SPI_DMA_RXTMP_MINSIZE 2048U + +struct au1550_spi { + struct spi_bitbang bitbang; + + volatile psc_spi_t __iomem *regs; + int irq; + unsigned freq_max; + unsigned freq_min; + + unsigned len; + unsigned tx_count; + unsigned rx_count; + const u8 *tx; + u8 *rx; + + void (*rx_word)(struct au1550_spi *hw); + void (*tx_word)(struct au1550_spi *hw); + int (*txrx_bufs)(struct spi_device *spi, struct spi_transfer *t); + irqreturn_t (*irq_callback)(struct au1550_spi *hw); + + struct completion master_done; + + unsigned usedma; + u32 dma_tx_id; + u32 dma_rx_id; + u32 dma_tx_ch; + u32 dma_rx_ch; + + u8 *dma_rx_tmpbuf; + unsigned dma_rx_tmpbuf_size; + u32 dma_rx_tmpbuf_addr; + + struct spi_master *master; + struct device *dev; + struct au1550_spi_info *pdata; +}; + + +/* we use an 8-bit memory device for dma transfers to/from spi fifo */ +static dbdev_tab_t au1550_spi_mem_dbdev = +{ + .dev_id = DBDMA_MEM_CHAN, + .dev_flags = DEV_FLAGS_ANYUSE|DEV_FLAGS_SYNC, + .dev_tsize = 0, + .dev_devwidth = 8, + .dev_physaddr = 0x00000000, + .dev_intlevel = 0, + .dev_intpolarity = 0 +}; + +static void au1550_spi_bits_handlers_set(struct au1550_spi *hw, int bpw); + + +/** + * compute BRG and DIV bits to setup spi clock based on main input clock rate + * that was specified in platform data structure + * according to au1550 datasheet: + * psc_tempclk = psc_mainclk / (2 << DIV) + * spiclk = psc_tempclk / (2 * (BRG + 1)) + * BRG valid range is 4..63 + * DIV valid range is 0..3 + */ +static u32 au1550_spi_baudcfg(struct au1550_spi *hw, unsigned speed_hz) +{ + u32 mainclk_hz = hw->pdata->mainclk_hz; + u32 div, brg; + + for (div = 0; div < 4; div++) { + brg = mainclk_hz / speed_hz / (4 << div); + /* now we have BRG+1 in brg, so count with that */ + if (brg < (4 + 1)) { + brg = (4 + 1); /* speed_hz too big */ + break; /* set lowest brg (div is == 0) */ + } + if (brg <= (63 + 1)) + break; /* we have valid brg and div */ + } + if (div == 4) { + div = 3; /* speed_hz too small */ + brg = (63 + 1); /* set highest brg and div */ + } + brg--; + return PSC_SPICFG_SET_BAUD(brg) | PSC_SPICFG_SET_DIV(div); +} + +static inline void au1550_spi_mask_ack_all(struct au1550_spi *hw) +{ + hw->regs->psc_spimsk = + PSC_SPIMSK_MM | PSC_SPIMSK_RR | PSC_SPIMSK_RO + | PSC_SPIMSK_RU | PSC_SPIMSK_TR | PSC_SPIMSK_TO + | PSC_SPIMSK_TU | PSC_SPIMSK_SD | PSC_SPIMSK_MD; + au_sync(); + + hw->regs->psc_spievent = + PSC_SPIEVNT_MM | PSC_SPIEVNT_RR | PSC_SPIEVNT_RO + | PSC_SPIEVNT_RU | PSC_SPIEVNT_TR | PSC_SPIEVNT_TO + | PSC_SPIEVNT_TU | PSC_SPIEVNT_SD | PSC_SPIEVNT_MD; + au_sync(); +} + +static void au1550_spi_reset_fifos(struct au1550_spi *hw) +{ + u32 pcr; + + hw->regs->psc_spipcr = PSC_SPIPCR_RC | PSC_SPIPCR_TC; + au_sync(); + do { + pcr = hw->regs->psc_spipcr; + au_sync(); + } while (pcr != 0); +} + +/* + * dma transfers are used for the most common spi word size of 8-bits + * we cannot easily change already set up dma channels' width, so if we wanted + * dma support for more than 8-bit words (up to 24 bits), we would need to + * setup dma channels from scratch on each spi transfer, based on bits_per_word + * instead we have pre set up 8 bit dma channels supporting spi 4 to 8 bits + * transfers, and 9 to 24 bits spi transfers will be done in pio irq based mode + * callbacks to handle dma or pio are set up in au1550_spi_bits_handlers_set() + */ +static void au1550_spi_chipsel(struct spi_device *spi, int value) +{ + struct au1550_spi *hw = spi_master_get_devdata(spi->master); + unsigned cspol = spi->mode & SPI_CS_HIGH ? 1 : 0; + u32 cfg, stat; + + switch (value) { + case BITBANG_CS_INACTIVE: + if (hw->pdata->deactivate_cs) + hw->pdata->deactivate_cs(hw->pdata, spi->chip_select, + cspol); + break; + + case BITBANG_CS_ACTIVE: + au1550_spi_bits_handlers_set(hw, spi->bits_per_word); + + cfg = hw->regs->psc_spicfg; + au_sync(); + hw->regs->psc_spicfg = cfg & ~PSC_SPICFG_DE_ENABLE; + au_sync(); + + if (spi->mode & SPI_CPOL) + cfg |= PSC_SPICFG_BI; + else + cfg &= ~PSC_SPICFG_BI; + if (spi->mode & SPI_CPHA) + cfg &= ~PSC_SPICFG_CDE; + else + cfg |= PSC_SPICFG_CDE; + + if (spi->mode & SPI_LSB_FIRST) + cfg |= PSC_SPICFG_MLF; + else + cfg &= ~PSC_SPICFG_MLF; + + if (hw->usedma && spi->bits_per_word <= 8) + cfg &= ~PSC_SPICFG_DD_DISABLE; + else + cfg |= PSC_SPICFG_DD_DISABLE; + cfg = PSC_SPICFG_CLR_LEN(cfg); + cfg |= PSC_SPICFG_SET_LEN(spi->bits_per_word); + + cfg = PSC_SPICFG_CLR_BAUD(cfg); + cfg &= ~PSC_SPICFG_SET_DIV(3); + cfg |= au1550_spi_baudcfg(hw, spi->max_speed_hz); + + hw->regs->psc_spicfg = cfg | PSC_SPICFG_DE_ENABLE; + au_sync(); + do { + stat = hw->regs->psc_spistat; + au_sync(); + } while ((stat & PSC_SPISTAT_DR) == 0); + + if (hw->pdata->activate_cs) + hw->pdata->activate_cs(hw->pdata, spi->chip_select, + cspol); + break; + } +} + +static int au1550_spi_setupxfer(struct spi_device *spi, struct spi_transfer *t) +{ + struct au1550_spi *hw = spi_master_get_devdata(spi->master); + unsigned bpw, hz; + u32 cfg, stat; + + bpw = t ? t->bits_per_word : spi->bits_per_word; + hz = t ? t->speed_hz : spi->max_speed_hz; + + if (bpw < 4 || bpw > 24) { + dev_err(&spi->dev, "setupxfer: invalid bits_per_word=%d\n", + bpw); + return -EINVAL; + } + if (hz > spi->max_speed_hz || hz > hw->freq_max || hz < hw->freq_min) { + dev_err(&spi->dev, "setupxfer: clock rate=%d out of range\n", + hz); + return -EINVAL; + } + + au1550_spi_bits_handlers_set(hw, spi->bits_per_word); + + cfg = hw->regs->psc_spicfg; + au_sync(); + hw->regs->psc_spicfg = cfg & ~PSC_SPICFG_DE_ENABLE; + au_sync(); + + if (hw->usedma && bpw <= 8) + cfg &= ~PSC_SPICFG_DD_DISABLE; + else + cfg |= PSC_SPICFG_DD_DISABLE; + cfg = PSC_SPICFG_CLR_LEN(cfg); + cfg |= PSC_SPICFG_SET_LEN(bpw); + + cfg = PSC_SPICFG_CLR_BAUD(cfg); + cfg &= ~PSC_SPICFG_SET_DIV(3); + cfg |= au1550_spi_baudcfg(hw, hz); + + hw->regs->psc_spicfg = cfg; + au_sync(); + + if (cfg & PSC_SPICFG_DE_ENABLE) { + do { + stat = hw->regs->psc_spistat; + au_sync(); + } while ((stat & PSC_SPISTAT_DR) == 0); + } + + au1550_spi_reset_fifos(hw); + au1550_spi_mask_ack_all(hw); + return 0; +} + +static int au1550_spi_setup(struct spi_device *spi) +{ + struct au1550_spi *hw = spi_master_get_devdata(spi->master); + + if (spi->bits_per_word == 0) + spi->bits_per_word = 8; + if (spi->bits_per_word < 4 || spi->bits_per_word > 24) { + dev_err(&spi->dev, "setup: invalid bits_per_word=%d\n", + spi->bits_per_word); + return -EINVAL; + } + + if (spi->max_speed_hz == 0) + spi->max_speed_hz = hw->freq_max; + if (spi->max_speed_hz > hw->freq_max + || spi->max_speed_hz < hw->freq_min) + return -EINVAL; + /* + * NOTE: cannot change speed and other hw settings immediately, + * otherwise sharing of spi bus is not possible, + * so do not call setupxfer(spi, NULL) here + */ + return 0; +} + +/* + * for dma spi transfers, we have to setup rx channel, otherwise there is + * no reliable way how to recognize that spi transfer is done + * dma complete callbacks are called before real spi transfer is finished + * and if only tx dma channel is set up (and rx fifo overflow event masked) + * spi master done event irq is not generated unless rx fifo is empty (emptied) + * so we need rx tmp buffer to use for rx dma if user does not provide one + */ +static int au1550_spi_dma_rxtmp_alloc(struct au1550_spi *hw, unsigned size) +{ + hw->dma_rx_tmpbuf = kmalloc(size, GFP_KERNEL); + if (!hw->dma_rx_tmpbuf) + return -ENOMEM; + hw->dma_rx_tmpbuf_size = size; + hw->dma_rx_tmpbuf_addr = dma_map_single(hw->dev, hw->dma_rx_tmpbuf, + size, DMA_FROM_DEVICE); + if (dma_mapping_error(hw->dma_rx_tmpbuf_addr)) { + kfree(hw->dma_rx_tmpbuf); + hw->dma_rx_tmpbuf = 0; + hw->dma_rx_tmpbuf_size = 0; + return -EFAULT; + } + return 0; +} + +static void au1550_spi_dma_rxtmp_free(struct au1550_spi *hw) +{ + dma_unmap_single(hw->dev, hw->dma_rx_tmpbuf_addr, + hw->dma_rx_tmpbuf_size, DMA_FROM_DEVICE); + kfree(hw->dma_rx_tmpbuf); + hw->dma_rx_tmpbuf = 0; + hw->dma_rx_tmpbuf_size = 0; +} + +static int au1550_spi_dma_txrxb(struct spi_device *spi, struct spi_transfer *t) +{ + struct au1550_spi *hw = spi_master_get_devdata(spi->master); + dma_addr_t dma_tx_addr; + dma_addr_t dma_rx_addr; + u32 res; + + hw->len = t->len; + hw->tx_count = 0; + hw->rx_count = 0; + + hw->tx = t->tx_buf; + hw->rx = t->rx_buf; + dma_tx_addr = t->tx_dma; + dma_rx_addr = t->rx_dma; + + /* + * check if buffers are already dma mapped, map them otherwise + * use rx buffer in place of tx if tx buffer was not provided + * use temp rx buffer (preallocated or realloc to fit) for rx dma + */ + if (t->rx_buf) { + if (t->rx_dma == 0) { /* if DMA_ADDR_INVALID, map it */ + dma_rx_addr = dma_map_single(hw->dev, + (void *)t->rx_buf, + t->len, DMA_FROM_DEVICE); + if (dma_mapping_error(dma_rx_addr)) + dev_err(hw->dev, "rx dma map error\n"); + } + } else { + if (t->len > hw->dma_rx_tmpbuf_size) { + int ret; + + au1550_spi_dma_rxtmp_free(hw); + ret = au1550_spi_dma_rxtmp_alloc(hw, max(t->len, + AU1550_SPI_DMA_RXTMP_MINSIZE)); + if (ret < 0) + return ret; + } + hw->rx = hw->dma_rx_tmpbuf; + dma_rx_addr = hw->dma_rx_tmpbuf_addr; + dma_sync_single_for_device(hw->dev, dma_rx_addr, + t->len, DMA_FROM_DEVICE); + } + if (t->tx_buf) { + if (t->tx_dma == 0) { /* if DMA_ADDR_INVALID, map it */ + dma_tx_addr = dma_map_single(hw->dev, + (void *)t->tx_buf, + t->len, DMA_TO_DEVICE); + if (dma_mapping_error(dma_tx_addr)) + dev_err(hw->dev, "tx dma map error\n"); + } + } else { + dma_sync_single_for_device(hw->dev, dma_rx_addr, + t->len, DMA_BIDIRECTIONAL); + hw->tx = hw->rx; + } + + /* put buffers on the ring */ + res = au1xxx_dbdma_put_dest(hw->dma_rx_ch, hw->rx, t->len); + if (!res) + dev_err(hw->dev, "rx dma put dest error\n"); + + res = au1xxx_dbdma_put_source(hw->dma_tx_ch, (void *)hw->tx, t->len); + if (!res) + dev_err(hw->dev, "tx dma put source error\n"); + + au1xxx_dbdma_start(hw->dma_rx_ch); + au1xxx_dbdma_start(hw->dma_tx_ch); + + /* by default enable nearly all events interrupt */ + hw->regs->psc_spimsk = PSC_SPIMSK_SD; + au_sync(); + + /* start the transfer */ + hw->regs->psc_spipcr = PSC_SPIPCR_MS; + au_sync(); + + wait_for_completion(&hw->master_done); + + au1xxx_dbdma_stop(hw->dma_tx_ch); + au1xxx_dbdma_stop(hw->dma_rx_ch); + + if (!t->rx_buf) { + /* using the temporal preallocated and premapped buffer */ + dma_sync_single_for_cpu(hw->dev, dma_rx_addr, t->len, + DMA_FROM_DEVICE); + } + /* unmap buffers if mapped above */ + if (t->rx_buf && t->rx_dma == 0 ) + dma_unmap_single(hw->dev, dma_rx_addr, t->len, + DMA_FROM_DEVICE); + if (t->tx_buf && t->tx_dma == 0 ) + dma_unmap_single(hw->dev, dma_tx_addr, t->len, + DMA_TO_DEVICE); + + return hw->rx_count < hw->tx_count ? hw->rx_count : hw->tx_count; +} + +static irqreturn_t au1550_spi_dma_irq_callback(struct au1550_spi *hw) +{ + u32 stat, evnt; + + stat = hw->regs->psc_spistat; + evnt = hw->regs->psc_spievent; + au_sync(); + if ((stat & PSC_SPISTAT_DI) == 0) { + dev_err(hw->dev, "Unexpected IRQ!\n"); + return IRQ_NONE; + } + + if ((evnt & (PSC_SPIEVNT_MM | PSC_SPIEVNT_RO + | PSC_SPIEVNT_RU | PSC_SPIEVNT_TO + | PSC_SPIEVNT_TU | PSC_SPIEVNT_SD)) + != 0) { + /* + * due to an spi error we consider transfer as done, + * so mask all events until before next transfer start + * and stop the possibly running dma immediatelly + */ + au1550_spi_mask_ack_all(hw); + au1xxx_dbdma_stop(hw->dma_rx_ch); + au1xxx_dbdma_stop(hw->dma_tx_ch); + + /* get number of transfered bytes */ + hw->rx_count = hw->len - au1xxx_get_dma_residue(hw->dma_rx_ch); + hw->tx_count = hw->len - au1xxx_get_dma_residue(hw->dma_tx_ch); + + au1xxx_dbdma_reset(hw->dma_rx_ch); + au1xxx_dbdma_reset(hw->dma_tx_ch); + au1550_spi_reset_fifos(hw); + + dev_err(hw->dev, + "Unexpected SPI error: event=0x%x stat=0x%x!\n", + evnt, stat); + + complete(&hw->master_done); + return IRQ_HANDLED; + } + + if ((evnt & PSC_SPIEVNT_MD) != 0) { + /* transfer completed successfully */ + au1550_spi_mask_ack_all(hw); + hw->rx_count = hw->len; + hw->tx_count = hw->len; + complete(&hw->master_done); + } + return IRQ_HANDLED; +} + + +/* routines to handle different word sizes in pio mode */ +#define AU1550_SPI_RX_WORD(size, mask) \ +static void au1550_spi_rx_word_##size(struct au1550_spi *hw) \ +{ \ + u32 fifoword = hw->regs->psc_spitxrx & (u32)(mask); \ + au_sync(); \ + if (hw->rx) { \ + *(u##size *)hw->rx = (u##size)fifoword; \ + hw->rx += (size) / 8; \ + } \ + hw->rx_count += (size) / 8; \ +} + +#define AU1550_SPI_TX_WORD(size, mask) \ +static void au1550_spi_tx_word_##size(struct au1550_spi *hw) \ +{ \ + u32 fifoword = 0; \ + if (hw->tx) { \ + fifoword = *(u##size *)hw->tx & (u32)(mask); \ + hw->tx += (size) / 8; \ + } \ + hw->tx_count += (size) / 8; \ + if (hw->tx_count >= hw->len) \ + fifoword |= PSC_SPITXRX_LC; \ + hw->regs->psc_spitxrx = fifoword; \ + au_sync(); \ +} + +AU1550_SPI_RX_WORD(8,0xff) +AU1550_SPI_RX_WORD(16,0xffff) +AU1550_SPI_RX_WORD(32,0xffffff) +AU1550_SPI_TX_WORD(8,0xff) +AU1550_SPI_TX_WORD(16,0xffff) +AU1550_SPI_TX_WORD(32,0xffffff) + +static int au1550_spi_pio_txrxb(struct spi_device *spi, struct spi_transfer *t) +{ + u32 stat, mask; + struct au1550_spi *hw = spi_master_get_devdata(spi->master); + + hw->tx = t->tx_buf; + hw->rx = t->rx_buf; + hw->len = t->len; + hw->tx_count = 0; + hw->rx_count = 0; + + /* by default enable nearly all events after filling tx fifo */ + mask = PSC_SPIMSK_SD; + + /* fill the transmit FIFO */ + while (hw->tx_count < hw->len) { + + hw->tx_word(hw); + + if (hw->tx_count >= hw->len) { + /* mask tx fifo request interrupt as we are done */ + mask |= PSC_SPIMSK_TR; + } + + stat = hw->regs->psc_spistat; + au_sync(); + if (stat & PSC_SPISTAT_TF) + break; + } + + /* enable event interrupts */ + hw->regs->psc_spimsk = mask; + au_sync(); + + /* start the transfer */ + hw->regs->psc_spipcr = PSC_SPIPCR_MS; + au_sync(); + + wait_for_completion(&hw->master_done); + + return hw->rx_count < hw->tx_count ? hw->rx_count : hw->tx_count; +} + +static irqreturn_t au1550_spi_pio_irq_callback(struct au1550_spi *hw) +{ + int busy; + u32 stat, evnt; + + stat = hw->regs->psc_spistat; + evnt = hw->regs->psc_spievent; + au_sync(); + if ((stat & PSC_SPISTAT_DI) == 0) { + dev_err(hw->dev, "Unexpected IRQ!\n"); + return IRQ_NONE; + } + + if ((evnt & (PSC_SPIEVNT_MM | PSC_SPIEVNT_RO + | PSC_SPIEVNT_RU | PSC_SPIEVNT_TO + | PSC_SPIEVNT_TU | PSC_SPIEVNT_SD)) + != 0) { + dev_err(hw->dev, + "Unexpected SPI error: event=0x%x stat=0x%x!\n", + evnt, stat); + /* + * due to an error we consider transfer as done, + * so mask all events until before next transfer start + */ + au1550_spi_mask_ack_all(hw); + au1550_spi_reset_fifos(hw); + complete(&hw->master_done); + return IRQ_HANDLED; + } + + /* + * while there is something to read from rx fifo + * or there is a space to write to tx fifo: + */ + do { + busy = 0; + stat = hw->regs->psc_spistat; + au_sync(); + + if ((stat & PSC_SPISTAT_RE) == 0 && hw->rx_count < hw->len) { + hw->rx_word(hw); + /* ack the receive request event */ + hw->regs->psc_spievent = PSC_SPIEVNT_RR; + au_sync(); + busy = 1; + } + + if ((stat & PSC_SPISTAT_TF) == 0 && hw->tx_count < hw->len) { + hw->tx_word(hw); + /* ack the transmit request event */ + hw->regs->psc_spievent = PSC_SPIEVNT_TR; + au_sync(); + busy = 1; + } + } while (busy); + + evnt = hw->regs->psc_spievent; + au_sync(); + + if (hw->rx_count >= hw->len || (evnt & PSC_SPIEVNT_MD) != 0) { + /* transfer completed successfully */ + au1550_spi_mask_ack_all(hw); + complete(&hw->master_done); + } + return IRQ_HANDLED; +} + +static int au1550_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t) +{ + struct au1550_spi *hw = spi_master_get_devdata(spi->master); + return hw->txrx_bufs(spi, t); +} + +static irqreturn_t au1550_spi_irq(int irq, void *dev, struct pt_regs *regs) +{ + struct au1550_spi *hw = dev; + return hw->irq_callback(hw); +} + +static void au1550_spi_bits_handlers_set(struct au1550_spi *hw, int bpw) +{ + if (bpw <= 8) { + if (hw->usedma) { + hw->txrx_bufs = &au1550_spi_dma_txrxb; + hw->irq_callback = &au1550_spi_dma_irq_callback; + } else { + hw->rx_word = &au1550_spi_rx_word_8; + hw->tx_word = &au1550_spi_tx_word_8; + hw->txrx_bufs = &au1550_spi_pio_txrxb; + hw->irq_callback = &au1550_spi_pio_irq_callback; + } + } else if (bpw <= 16) { + hw->rx_word = &au1550_spi_rx_word_16; + hw->tx_word = &au1550_spi_tx_word_16; + hw->txrx_bufs = &au1550_spi_pio_txrxb; + hw->irq_callback = &au1550_spi_pio_irq_callback; + } else { + hw->rx_word = &au1550_spi_rx_word_32; + hw->tx_word = &au1550_spi_tx_word_32; + hw->txrx_bufs = &au1550_spi_pio_txrxb; + hw->irq_callback = &au1550_spi_pio_irq_callback; + } +} + +static void __init au1550_spi_setup_psc_as_spi(struct au1550_spi *hw) +{ + u32 stat, cfg; + + /* set up the PSC for SPI mode */ + hw->regs->psc_ctrl = PSC_CTRL_DISABLE; + au_sync(); + hw->regs->psc_sel = PSC_SEL_PS_SPIMODE; + au_sync(); + + hw->regs->psc_spicfg = 0; + au_sync(); + + hw->regs->psc_ctrl = PSC_CTRL_ENABLE; + au_sync(); + + do { + stat = hw->regs->psc_spistat; + au_sync(); + } while ((stat & PSC_SPISTAT_SR) == 0); + + + cfg = hw->usedma ? 0 : PSC_SPICFG_DD_DISABLE; + cfg |= PSC_SPICFG_SET_LEN(8); + cfg |= PSC_SPICFG_RT_FIFO8 | PSC_SPICFG_TT_FIFO8; + /* use minimal allowed brg and div values as initial setting: */ + cfg |= PSC_SPICFG_SET_BAUD(4) | PSC_SPICFG_SET_DIV(0); + +#ifdef AU1550_SPI_DEBUG_LOOPBACK + cfg |= PSC_SPICFG_LB; +#endif + + hw->regs->psc_spicfg = cfg; + au_sync(); + + au1550_spi_mask_ack_all(hw); + + hw->regs->psc_spicfg |= PSC_SPICFG_DE_ENABLE; + au_sync(); + + do { + stat = hw->regs->psc_spistat; + au_sync(); + } while ((stat & PSC_SPISTAT_DR) == 0); +} + + +static int __init au1550_spi_probe(struct platform_device *pdev) +{ + struct au1550_spi *hw; + struct spi_master *master; + int err = 0; + + master = spi_alloc_master(&pdev->dev, sizeof(struct au1550_spi)); + if (master == NULL) { + dev_err(&pdev->dev, "No memory for spi_master\n"); + err = -ENOMEM; + goto err_nomem; + } + + hw = spi_master_get_devdata(master); + + hw->master = spi_master_get(master); + hw->pdata = pdev->dev.platform_data; + hw->dev = &pdev->dev; + + if (hw->pdata == NULL) { + dev_err(&pdev->dev, "No platform data supplied\n"); + err = -ENOENT; + goto err_no_pdata; + } + + platform_set_drvdata(pdev, hw); + + init_completion(&hw->master_done); + + hw->bitbang.master = hw->master; + hw->bitbang.setup_transfer = au1550_spi_setupxfer; + hw->bitbang.chipselect = au1550_spi_chipsel; + hw->bitbang.master->setup = au1550_spi_setup; + hw->bitbang.txrx_bufs = au1550_spi_txrx_bufs; + + switch (hw->pdata->bus_num) { + case 0: + hw->irq = AU1550_PSC0_INT; + hw->regs = (volatile psc_spi_t *)PSC0_BASE_ADDR; + hw->dma_rx_id = DSCR_CMD0_PSC0_RX; + hw->dma_tx_id = DSCR_CMD0_PSC0_TX; + break; + case 1: + hw->irq = AU1550_PSC1_INT; + hw->regs = (volatile psc_spi_t *)PSC1_BASE_ADDR; + hw->dma_rx_id = DSCR_CMD0_PSC1_RX; + hw->dma_tx_id = DSCR_CMD0_PSC1_TX; + break; + case 2: + hw->irq = AU1550_PSC2_INT; + hw->regs = (volatile psc_spi_t *)PSC2_BASE_ADDR; + hw->dma_rx_id = DSCR_CMD0_PSC2_RX; + hw->dma_tx_id = DSCR_CMD0_PSC2_TX; + break; + case 3: + hw->irq = AU1550_PSC3_INT; + hw->regs = (volatile psc_spi_t *)PSC3_BASE_ADDR; + hw->dma_rx_id = DSCR_CMD0_PSC3_RX; + hw->dma_tx_id = DSCR_CMD0_PSC3_TX; + break; + default: + dev_err(&pdev->dev, "Wrong bus_num of SPI\n"); + err = -ENOENT; + goto err_no_pdata; + } + + if (request_mem_region((unsigned long)hw->regs, sizeof(psc_spi_t), + pdev->name) == NULL) { + dev_err(&pdev->dev, "Cannot reserve iomem region\n"); + err = -ENXIO; + goto err_no_iores; + } + + + if (usedma) { + if (pdev->dev.dma_mask == NULL) + dev_warn(&pdev->dev, "no dma mask\n"); + else + hw->usedma = 1; + } + + if (hw->usedma) { + /* + * create memory device with 8 bits dev_devwidth + * needed for proper byte ordering to spi fifo + */ + int memid = au1xxx_ddma_add_device(&au1550_spi_mem_dbdev); + if (!memid) { + dev_err(&pdev->dev, + "Cannot create dma 8 bit mem device\n"); + err = -ENXIO; + goto err_dma_add_dev; + } + + hw->dma_tx_ch = au1xxx_dbdma_chan_alloc(memid, + hw->dma_tx_id, NULL, (void *)hw); + if (hw->dma_tx_ch == 0) { + dev_err(&pdev->dev, + "Cannot allocate tx dma channel\n"); + err = -ENXIO; + goto err_no_txdma; + } + au1xxx_dbdma_set_devwidth(hw->dma_tx_ch, 8); + if (au1xxx_dbdma_ring_alloc(hw->dma_tx_ch, + AU1550_SPI_DBDMA_DESCRIPTORS) == 0) { + dev_err(&pdev->dev, + "Cannot allocate tx dma descriptors\n"); + err = -ENXIO; + goto err_no_txdma_descr; + } + + + hw->dma_rx_ch = au1xxx_dbdma_chan_alloc(hw->dma_rx_id, + memid, NULL, (void *)hw); + if (hw->dma_rx_ch == 0) { + dev_err(&pdev->dev, + "Cannot allocate rx dma channel\n"); + err = -ENXIO; + goto err_no_rxdma; + } + au1xxx_dbdma_set_devwidth(hw->dma_rx_ch, 8); + if (au1xxx_dbdma_ring_alloc(hw->dma_rx_ch, + AU1550_SPI_DBDMA_DESCRIPTORS) == 0) { + dev_err(&pdev->dev, + "Cannot allocate rx dma descriptors\n"); + err = -ENXIO; + goto err_no_rxdma_descr; + } + + err = au1550_spi_dma_rxtmp_alloc(hw, + AU1550_SPI_DMA_RXTMP_MINSIZE); + if (err < 0) { + dev_err(&pdev->dev, + "Cannot allocate initial rx dma tmp buffer\n"); + goto err_dma_rxtmp_alloc; + } + } + + au1550_spi_bits_handlers_set(hw, 8); + + err = request_irq(hw->irq, au1550_spi_irq, 0, pdev->name, hw); + if (err) { + dev_err(&pdev->dev, "Cannot claim IRQ\n"); + goto err_no_irq; + } + + master->bus_num = hw->pdata->bus_num; + master->num_chipselect = hw->pdata->num_chipselect; + + /* + * precompute valid range for spi freq - from au1550 datasheet: + * psc_tempclk = psc_mainclk / (2 << DIV) + * spiclk = psc_tempclk / (2 * (BRG + 1)) + * BRG valid range is 4..63 + * DIV valid range is 0..3 + * round the min and max frequencies to values that would still + * produce valid brg and div + */ + { + int min_div = (2 << 0) * (2 * (4 + 1)); + int max_div = (2 << 3) * (2 * (63 + 1)); + hw->freq_max = hw->pdata->mainclk_hz / min_div; + hw->freq_min = hw->pdata->mainclk_hz / (max_div + 1) + 1; + } + + au1550_spi_setup_psc_as_spi(hw); + + err = spi_bitbang_start(&hw->bitbang); + if (err) { + dev_err(&pdev->dev, "Failed to register SPI master\n"); + goto err_register; + } + + dev_info(&pdev->dev, + "spi master registered: bus_num=%d num_chipselect=%d\n", + master->bus_num, master->num_chipselect); + + return 0; + +err_register: + free_irq(hw->irq, hw); + +err_no_irq: + au1550_spi_dma_rxtmp_free(hw); + +err_dma_rxtmp_alloc: +err_no_rxdma_descr: + if (hw->usedma) + au1xxx_dbdma_chan_free(hw->dma_rx_ch); + +err_no_rxdma: +err_no_txdma_descr: + if (hw->usedma) + au1xxx_dbdma_chan_free(hw->dma_tx_ch); + +err_no_txdma: +err_dma_add_dev: + release_mem_region((unsigned long)hw->regs, sizeof(psc_spi_t)); + +err_no_iores: +err_no_pdata: + spi_master_put(hw->master); + +err_nomem: + return err; +} + +static int __exit au1550_spi_remove(struct platform_device *pdev) +{ + struct au1550_spi *hw = platform_get_drvdata(pdev); + + dev_info(&pdev->dev, "spi master remove: bus_num=%d\n", + hw->master->bus_num); + + spi_bitbang_stop(&hw->bitbang); + free_irq(hw->irq, hw); + release_mem_region((unsigned long)hw->regs, sizeof(psc_spi_t)); + + if (hw->usedma) { + au1550_spi_dma_rxtmp_free(hw); + au1xxx_dbdma_chan_free(hw->dma_rx_ch); + au1xxx_dbdma_chan_free(hw->dma_tx_ch); + } + + platform_set_drvdata(pdev, NULL); + + spi_master_put(hw->master); + return 0; +} + +static struct platform_driver au1550_spi_drv = { + .remove = __exit_p(au1550_spi_remove), + .driver = { + .name = "au1550-spi", + .owner = THIS_MODULE, + }, +}; + +static int __init au1550_spi_init(void) +{ + return platform_driver_probe(&au1550_spi_drv, au1550_spi_probe); +} +module_init(au1550_spi_init); + +static void __exit au1550_spi_exit(void) +{ + platform_driver_unregister(&au1550_spi_drv); +} +module_exit(au1550_spi_exit); + +MODULE_DESCRIPTION("Au1550 PSC SPI Driver"); +MODULE_AUTHOR("Jan Nikitenko <jan.nikitenko@gmail.com>"); +MODULE_LICENSE("GPL"); diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 6657331eed93..c3219b29b5ac 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -152,6 +152,11 @@ static void spi_drv_shutdown(struct device *dev) sdrv->shutdown(to_spi_device(dev)); } +/** + * spi_register_driver - register a SPI driver + * @sdrv: the driver to register + * Context: can sleep + */ int spi_register_driver(struct spi_driver *sdrv) { sdrv->driver.bus = &spi_bus_type; @@ -183,7 +188,13 @@ static LIST_HEAD(board_list); static DECLARE_MUTEX(board_lock); -/* On typical mainboards, this is purely internal; and it's not needed +/** + * spi_new_device - instantiate one new SPI device + * @master: Controller to which device is connected + * @chip: Describes the SPI device + * Context: can sleep + * + * On typical mainboards, this is purely internal; and it's not needed * after board init creates the hard-wired devices. Some development * platforms may not be able to use spi_register_board_info though, and * this is exported so that for example a USB or parport based adapter @@ -251,7 +262,12 @@ fail: } EXPORT_SYMBOL_GPL(spi_new_device); -/* +/** + * spi_register_board_info - register SPI devices for a given board + * @info: array of chip descriptors + * @n: how many descriptors are provided + * Context: can sleep + * * Board-specific early init code calls this (probably during arch_initcall) * with segments of the SPI device table. Any device nodes are created later, * after the relevant parent SPI controller (bus_num) is defined. We keep @@ -337,9 +353,10 @@ static struct class spi_master_class = { /** * spi_alloc_master - allocate SPI master controller * @dev: the controller, possibly using the platform_bus - * @size: how much driver-private data to preallocate; the pointer to this + * @size: how much zeroed driver-private data to allocate; the pointer to this * memory is in the class_data field of the returned class_device, * accessible with spi_master_get_devdata(). + * Context: can sleep * * This call is used only by SPI master controller drivers, which are the * only ones directly touching chip registers. It's how they allocate @@ -375,6 +392,7 @@ EXPORT_SYMBOL_GPL(spi_alloc_master); /** * spi_register_master - register SPI master controller * @master: initialized master, originally from spi_alloc_master() + * Context: can sleep * * SPI master controllers connect to their drivers using some non-SPI bus, * such as the platform bus. The final stage of probe() in that code @@ -437,6 +455,7 @@ static int __unregister(struct device *dev, void *unused) /** * spi_unregister_master - unregister SPI master controller * @master: the master being unregistered + * Context: can sleep * * This call is used only by SPI master controller drivers, which are the * only ones directly touching chip registers. @@ -455,6 +474,7 @@ EXPORT_SYMBOL_GPL(spi_unregister_master); /** * spi_busnum_to_master - look up master associated with bus_num * @bus_num: the master's bus number + * Context: can sleep * * This call may be used with devices that are registered after * arch init time. It returns a refcounted pointer to the relevant @@ -492,6 +512,7 @@ static void spi_complete(void *arg) * spi_sync - blocking/synchronous SPI data transfers * @spi: device with which data will be exchanged * @message: describes the data transfers + * Context: can sleep * * This call may only be used from a context that may sleep. The sleep * is non-interruptible, and has no timeout. Low-overhead controller @@ -508,7 +529,7 @@ static void spi_complete(void *arg) * * The return value is a negative error code if the message could not be * submitted, else zero. When the value is zero, then message->status is - * also defined: it's the completion code for the transfer, either zero + * also defined; it's the completion code for the transfer, either zero * or a negative error code from the controller driver. */ int spi_sync(struct spi_device *spi, struct spi_message *message) @@ -538,6 +559,7 @@ static u8 *buf; * @n_tx: size of txbuf, in bytes * @rxbuf: buffer into which data will be read * @n_rx: size of rxbuf, in bytes (need not be dma-safe) + * Context: can sleep * * This performs a half duplex MicroWire style transaction with the * device, sending txbuf and then reading rxbuf. The return value @@ -545,7 +567,8 @@ static u8 *buf; * This call may only be used from a context that may sleep. * * Parameters to this routine are always copied using a small buffer; - * performance-sensitive or bulk transfer code should instead use + * portable code should never use this for more than 32 bytes. + * Performance-sensitive or bulk transfer code should instead use * spi_{async,sync}() calls with dma-safe buffers. */ int spi_write_then_read(struct spi_device *spi, diff --git a/drivers/spi/spi_butterfly.c b/drivers/spi/spi_butterfly.c index 312987a03210..0ee2b2090252 100644 --- a/drivers/spi/spi_butterfly.c +++ b/drivers/spi/spi_butterfly.c @@ -20,7 +20,7 @@ #include <linux/kernel.h> #include <linux/init.h> #include <linux/delay.h> -#include <linux/platform_device.h> +#include <linux/device.h> #include <linux/parport.h> #include <linux/sched.h> @@ -40,8 +40,6 @@ * and use this custom parallel port cable. */ -#undef HAVE_USI /* nyet */ - /* DATA output bits (pins 2..9 == D0..D7) */ #define butterfly_nreset (1 << 1) /* pin 3 */ @@ -49,19 +47,13 @@ #define spi_sck_bit (1 << 0) /* pin 2 */ #define spi_mosi_bit (1 << 7) /* pin 9 */ -#define usi_sck_bit (1 << 3) /* pin 5 */ -#define usi_mosi_bit (1 << 4) /* pin 6 */ - #define vcc_bits ((1 << 6) | (1 << 5)) /* pins 7, 8 */ /* STATUS input bits */ #define spi_miso_bit PARPORT_STATUS_BUSY /* pin 11 */ -#define usi_miso_bit PARPORT_STATUS_PAPEROUT /* pin 12 */ - /* CONTROL output bits */ #define spi_cs_bit PARPORT_CONTROL_SELECT /* pin 17 */ -/* USI uses no chipselect */ @@ -70,15 +62,6 @@ static inline struct butterfly *spidev_to_pp(struct spi_device *spi) return spi->controller_data; } -static inline int is_usidev(struct spi_device *spi) -{ -#ifdef HAVE_USI - return spi->chip_select != 1; -#else - return 0; -#endif -} - struct butterfly { /* REVISIT ... for now, this must be first */ @@ -97,23 +80,13 @@ struct butterfly { /*----------------------------------------------------------------------*/ -/* - * these routines may be slower than necessary because they're hiding - * the fact that there are two different SPI busses on this cable: one - * to the DataFlash chip (or AVR SPI controller), the other to the - * AVR USI controller. - */ - static inline void setsck(struct spi_device *spi, int is_on) { struct butterfly *pp = spidev_to_pp(spi); u8 bit, byte = pp->lastbyte; - if (is_usidev(spi)) - bit = usi_sck_bit; - else - bit = spi_sck_bit; + bit = spi_sck_bit; if (is_on) byte |= bit; @@ -129,10 +102,7 @@ setmosi(struct spi_device *spi, int is_on) struct butterfly *pp = spidev_to_pp(spi); u8 bit, byte = pp->lastbyte; - if (is_usidev(spi)) - bit = usi_mosi_bit; - else - bit = spi_mosi_bit; + bit = spi_mosi_bit; if (is_on) byte |= bit; @@ -148,10 +118,7 @@ static inline int getmiso(struct spi_device *spi) int value; u8 bit; - if (is_usidev(spi)) - bit = usi_miso_bit; - else - bit = spi_miso_bit; + bit = spi_miso_bit; /* only STATUS_BUSY is NOT negated */ value = !(parport_read_status(pp->port) & bit); @@ -166,10 +133,6 @@ static void butterfly_chipselect(struct spi_device *spi, int value) if (value != BITBANG_CS_INACTIVE) setsck(spi, spi->mode & SPI_CPOL); - /* no chipselect on this USI link config */ - if (is_usidev(spi)) - return; - /* here, value == "activate or not"; * most PARPORT_CONTROL_* bits are negated, so we must * morph it to value == "bit value to write in control register" @@ -237,24 +200,16 @@ static void butterfly_attach(struct parport *p) int status; struct butterfly *pp; struct spi_master *master; - struct platform_device *pdev; + struct device *dev = p->physport->dev; - if (butterfly) + if (butterfly || !dev) return; /* REVISIT: this just _assumes_ a butterfly is there ... no probe, * and no way to be selective about what it binds to. */ - /* FIXME where should master->cdev.dev come from? - * e.g. /sys/bus/pnp0/00:0b, some PCI thing, etc - * setting up a platform device like this is an ugly kluge... - */ - pdev = platform_device_register_simple("butterfly", -1, NULL, 0); - if (IS_ERR(pdev)) - return; - - master = spi_alloc_master(&pdev->dev, sizeof *pp); + master = spi_alloc_master(dev, sizeof *pp); if (!master) { status = -ENOMEM; goto done; @@ -300,7 +255,7 @@ static void butterfly_attach(struct parport *p) parport_frob_control(pp->port, spi_cs_bit, 0); /* stabilize power with chip in reset (nRESET), and - * both spi_sck_bit and usi_sck_bit clear (CPOL=0) + * spi_sck_bit clear (CPOL=0) */ pp->lastbyte |= vcc_bits; parport_write_data(pp->port, pp->lastbyte); @@ -334,23 +289,6 @@ static void butterfly_attach(struct parport *p) pr_debug("%s: dataflash at %s\n", p->name, pp->dataflash->dev.bus_id); -#ifdef HAVE_USI - /* Bus 2 is only for talking to the AVR, and it can work no - * matter who masters bus 1; needs appropriate AVR firmware. - */ - pp->info[1].max_speed_hz = 10 /* ?? */ * 1000 * 1000; - strcpy(pp->info[1].modalias, "butterfly"); - // pp->info[1].platform_data = ... TBD ... ; - pp->info[1].chip_select = 2, - pp->info[1].controller_data = pp; - pp->butterfly = spi_new_device(pp->bitbang.master, &pp->info[1]); - if (pp->butterfly) - pr_debug("%s: butterfly at %s\n", p->name, - pp->butterfly->dev.bus_id); - - /* FIXME setup ACK for the IRQ line ... */ -#endif - // dev_info(_what?_, ...) pr_info("%s: AVR Butterfly\n", p->name); butterfly = pp; @@ -366,14 +304,12 @@ clean1: clean0: (void) spi_master_put(pp->bitbang.master); done: - platform_device_unregister(pdev); pr_debug("%s: butterfly probe, fail %d\n", p->name, status); } static void butterfly_detach(struct parport *p) { struct butterfly *pp; - struct platform_device *pdev; int status; /* FIXME this global is ugly ... but, how to quickly get from @@ -386,7 +322,6 @@ static void butterfly_detach(struct parport *p) butterfly = NULL; /* stop() unregisters child devices too */ - pdev = to_platform_device(pp->bitbang.master->cdev.dev); status = spi_bitbang_stop(&pp->bitbang); /* turn off VCC */ @@ -397,8 +332,6 @@ static void butterfly_detach(struct parport *p) parport_unregister_device(pp->pd); (void) spi_master_put(pp->bitbang.master); - - platform_device_unregister(pdev); } static struct parport_driver butterfly_driver = { diff --git a/drivers/spi/spidev.c b/drivers/spi/spidev.c new file mode 100644 index 000000000000..c0a6dce800a3 --- /dev/null +++ b/drivers/spi/spidev.c @@ -0,0 +1,584 @@ +/* + * spidev.c -- simple synchronous userspace interface to SPI devices + * + * Copyright (C) 2006 SWAPP + * Andrea Paterniani <a.paterniani@swapp-eng.it> + * Copyright (C) 2007 David Brownell (simplification, cleanup) + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#include <linux/init.h> +#include <linux/module.h> +#include <linux/ioctl.h> +#include <linux/fs.h> +#include <linux/device.h> +#include <linux/list.h> +#include <linux/errno.h> +#include <linux/mutex.h> +#include <linux/slab.h> + +#include <linux/spi/spi.h> +#include <linux/spi/spidev.h> + +#include <asm/uaccess.h> + + +/* + * This supports acccess to SPI devices using normal userspace I/O calls. + * Note that while traditional UNIX/POSIX I/O semantics are half duplex, + * and often mask message boundaries, full SPI support requires full duplex + * transfers. There are several kinds of of internal message boundaries to + * handle chipselect management and other protocol options. + * + * SPI has a character major number assigned. We allocate minor numbers + * dynamically using a bitmask. You must use hotplug tools, such as udev + * (or mdev with busybox) to create and destroy the /dev/spidevB.C device + * nodes, since there is no fixed association of minor numbers with any + * particular SPI bus or device. + */ +#define SPIDEV_MAJOR 153 /* assigned */ +#define N_SPI_MINORS 32 /* ... up to 256 */ + +static unsigned long minors[N_SPI_MINORS / BITS_PER_LONG]; + + +/* Bit masks for spi_device.mode management */ +#define SPI_MODE_MASK (SPI_CPHA | SPI_CPOL) + + +struct spidev_data { + struct device dev; + struct spi_device *spi; + struct list_head device_entry; + + struct mutex buf_lock; + unsigned users; + u8 *buffer; +}; + +static LIST_HEAD(device_list); +static DEFINE_MUTEX(device_list_lock); + +static unsigned bufsiz = 4096; +module_param(bufsiz, uint, S_IRUGO); +MODULE_PARM_DESC(bufsiz, "data bytes in biggest supported SPI message"); + +/*-------------------------------------------------------------------------*/ + +/* Read-only message with current device setup */ +static ssize_t +spidev_read(struct file *filp, char __user *buf, size_t count, loff_t *f_pos) +{ + struct spidev_data *spidev; + struct spi_device *spi; + ssize_t status = 0; + + /* chipselect only toggles at start or end of operation */ + if (count > bufsiz) + return -EMSGSIZE; + + spidev = filp->private_data; + spi = spidev->spi; + + mutex_lock(&spidev->buf_lock); + status = spi_read(spi, spidev->buffer, count); + if (status == 0) { + unsigned long missing; + + missing = copy_to_user(buf, spidev->buffer, count); + if (count && missing == count) + status = -EFAULT; + else + status = count - missing; + } + mutex_unlock(&spidev->buf_lock); + + return status; +} + +/* Write-only message with current device setup */ +static ssize_t +spidev_write(struct file *filp, const char __user *buf, + size_t count, loff_t *f_pos) +{ + struct spidev_data *spidev; + struct spi_device *spi; + ssize_t status = 0; + unsigned long missing; + + /* chipselect only toggles at start or end of operation */ + if (count > bufsiz) + return -EMSGSIZE; + + spidev = filp->private_data; + spi = spidev->spi; + + mutex_lock(&spidev->buf_lock); + missing = copy_from_user(spidev->buffer, buf, count); + if (missing == 0) { + status = spi_write(spi, spidev->buffer, count); + if (status == 0) + status = count; + } else + status = -EFAULT; + mutex_unlock(&spidev->buf_lock); + + return status; +} + +static int spidev_message(struct spidev_data *spidev, + struct spi_ioc_transfer *u_xfers, unsigned n_xfers) +{ + struct spi_message msg; + struct spi_transfer *k_xfers; + struct spi_transfer *k_tmp; + struct spi_ioc_transfer *u_tmp; + struct spi_device *spi = spidev->spi; + unsigned n, total; + u8 *buf; + int status = -EFAULT; + + spi_message_init(&msg); + k_xfers = kcalloc(n_xfers, sizeof(*k_tmp), GFP_KERNEL); + if (k_xfers == NULL) + return -ENOMEM; + + /* Construct spi_message, copying any tx data to bounce buffer. + * We walk the array of user-provided transfers, using each one + * to initialize a kernel version of the same transfer. + */ + mutex_lock(&spidev->buf_lock); + buf = spidev->buffer; + total = 0; + for (n = n_xfers, k_tmp = k_xfers, u_tmp = u_xfers; + n; + n--, k_tmp++, u_tmp++) { + k_tmp->len = u_tmp->len; + + if (u_tmp->rx_buf) { + k_tmp->rx_buf = buf; + if (!access_ok(VERIFY_WRITE, u_tmp->rx_buf, u_tmp->len)) + goto done; + } + if (u_tmp->tx_buf) { + k_tmp->tx_buf = buf; + if (copy_from_user(buf, (const u8 __user *)u_tmp->tx_buf, + u_tmp->len)) + goto done; + } + + total += k_tmp->len; + if (total > bufsiz) { + status = -EMSGSIZE; + goto done; + } + buf += k_tmp->len; + + k_tmp->cs_change = !!u_tmp->cs_change; + k_tmp->bits_per_word = u_tmp->bits_per_word; + k_tmp->delay_usecs = u_tmp->delay_usecs; + k_tmp->speed_hz = u_tmp->speed_hz; +#ifdef VERBOSE + dev_dbg(&spi->dev, + " xfer len %zd %s%s%s%dbits %u usec %uHz\n", + u_tmp->len, + u_tmp->rx_buf ? "rx " : "", + u_tmp->tx_buf ? "tx " : "", + u_tmp->cs_change ? "cs " : "", + u_tmp->bits_per_word ? : spi->bits_per_word, + u_tmp->delay_usecs, + u_tmp->speed_hz ? : spi->max_speed_hz); +#endif + spi_message_add_tail(k_tmp, &msg); + } + + status = spi_sync(spi, &msg); + if (status < 0) + goto done; + + /* copy any rx data out of bounce buffer */ + buf = spidev->buffer; + for (n = n_xfers, u_tmp = u_xfers; n; n--, u_tmp++) { + if (u_tmp->rx_buf) { + if (__copy_to_user((u8 __user *)u_tmp->rx_buf, buf, + u_tmp->len)) { + status = -EFAULT; + goto done; + } + } + buf += u_tmp->len; + } + status = total; + +done: + mutex_unlock(&spidev->buf_lock); + kfree(k_xfers); + return status; +} + +static int +spidev_ioctl(struct inode *inode, struct file *filp, + unsigned int cmd, unsigned long arg) +{ + int err = 0; + int retval = 0; + struct spidev_data *spidev; + struct spi_device *spi; + u32 tmp; + unsigned n_ioc; + struct spi_ioc_transfer *ioc; + + /* Check type and command number */ + if (_IOC_TYPE(cmd) != SPI_IOC_MAGIC) + return -ENOTTY; + + /* Check access direction once here; don't repeat below. + * IOC_DIR is from the user perspective, while access_ok is + * from the kernel perspective; so they look reversed. + */ + if (_IOC_DIR(cmd) & _IOC_READ) + err = !access_ok(VERIFY_WRITE, + (void __user *)arg, _IOC_SIZE(cmd)); + if (err == 0 && _IOC_DIR(cmd) & _IOC_WRITE) + err = !access_ok(VERIFY_READ, + (void __user *)arg, _IOC_SIZE(cmd)); + if (err) + return -EFAULT; + + spidev = filp->private_data; + spi = spidev->spi; + + switch (cmd) { + /* read requests */ + case SPI_IOC_RD_MODE: + retval = __put_user(spi->mode & SPI_MODE_MASK, + (__u8 __user *)arg); + break; + case SPI_IOC_RD_LSB_FIRST: + retval = __put_user((spi->mode & SPI_LSB_FIRST) ? 1 : 0, + (__u8 __user *)arg); + break; + case SPI_IOC_RD_BITS_PER_WORD: + retval = __put_user(spi->bits_per_word, (__u8 __user *)arg); + break; + case SPI_IOC_RD_MAX_SPEED_HZ: + retval = __put_user(spi->max_speed_hz, (__u32 __user *)arg); + break; + + /* write requests */ + case SPI_IOC_WR_MODE: + retval = __get_user(tmp, (u8 __user *)arg); + if (retval == 0) { + u8 save = spi->mode; + + if (tmp & ~SPI_MODE_MASK) { + retval = -EINVAL; + break; + } + + tmp |= spi->mode & ~SPI_MODE_MASK; + spi->mode = (u8)tmp; + retval = spi_setup(spi); + if (retval < 0) + spi->mode = save; + else + dev_dbg(&spi->dev, "spi mode %02x\n", tmp); + } + break; + case SPI_IOC_WR_LSB_FIRST: + retval = __get_user(tmp, (__u8 __user *)arg); + if (retval == 0) { + u8 save = spi->mode; + + if (tmp) + spi->mode |= SPI_LSB_FIRST; + else + spi->mode &= ~SPI_LSB_FIRST; + retval = spi_setup(spi); + if (retval < 0) + spi->mode = save; + else + dev_dbg(&spi->dev, "%csb first\n", + tmp ? 'l' : 'm'); + } + break; + case SPI_IOC_WR_BITS_PER_WORD: + retval = __get_user(tmp, (__u8 __user *)arg); + if (retval == 0) { + u8 save = spi->bits_per_word; + + spi->bits_per_word = tmp; + retval = spi_setup(spi); + if (retval < 0) + spi->bits_per_word = save; + else + dev_dbg(&spi->dev, "%d bits per word\n", tmp); + } + break; + case SPI_IOC_WR_MAX_SPEED_HZ: + retval = __get_user(tmp, (__u32 __user *)arg); + if (retval == 0) { + u32 save = spi->max_speed_hz; + + spi->max_speed_hz = tmp; + retval = spi_setup(spi); + if (retval < 0) + spi->max_speed_hz = save; + else + dev_dbg(&spi->dev, "%d Hz (max)\n", tmp); + } + break; + + default: + /* segmented and/or full-duplex I/O request */ + if (_IOC_NR(cmd) != _IOC_NR(SPI_IOC_MESSAGE(0)) + || _IOC_DIR(cmd) != _IOC_WRITE) + return -ENOTTY; + + tmp = _IOC_SIZE(cmd); + if ((tmp % sizeof(struct spi_ioc_transfer)) != 0) { + retval = -EINVAL; + break; + } + n_ioc = tmp / sizeof(struct spi_ioc_transfer); + if (n_ioc == 0) + break; + + /* copy into scratch area */ + ioc = kmalloc(tmp, GFP_KERNEL); + if (!ioc) { + retval = -ENOMEM; + break; + } + if (__copy_from_user(ioc, (void __user *)arg, tmp)) { + retval = -EFAULT; + break; + } + + /* translate to spi_message, execute */ + retval = spidev_message(spidev, ioc, n_ioc); + kfree(ioc); + break; + } + return retval; +} + +static int spidev_open(struct inode *inode, struct file *filp) +{ + struct spidev_data *spidev; + int status = -ENXIO; + + mutex_lock(&device_list_lock); + + list_for_each_entry(spidev, &device_list, device_entry) { + if (spidev->dev.devt == inode->i_rdev) { + status = 0; + break; + } + } + if (status == 0) { + if (!spidev->buffer) { + spidev->buffer = kmalloc(bufsiz, GFP_KERNEL); + if (!spidev->buffer) { + dev_dbg(&spidev->spi->dev, "open/ENOMEM\n"); + status = -ENOMEM; + } + } + if (status == 0) { + spidev->users++; + filp->private_data = spidev; + nonseekable_open(inode, filp); + } + } else + pr_debug("spidev: nothing for minor %d\n", iminor(inode)); + + mutex_unlock(&device_list_lock); + return status; +} + +static int spidev_release(struct inode *inode, struct file *filp) +{ + struct spidev_data *spidev; + int status = 0; + + mutex_lock(&device_list_lock); + spidev = filp->private_data; + filp->private_data = NULL; + spidev->users--; + if (!spidev->users) { + kfree(spidev->buffer); + spidev->buffer = NULL; + } + mutex_unlock(&device_list_lock); + + return status; +} + +static struct file_operations spidev_fops = { + .owner = THIS_MODULE, + /* REVISIT switch to aio primitives, so that userspace + * gets more complete API coverage. It'll simplify things + * too, except for the locking. + */ + .write = spidev_write, + .read = spidev_read, + .ioctl = spidev_ioctl, + .open = spidev_open, + .release = spidev_release, +}; + +/*-------------------------------------------------------------------------*/ + +/* The main reason to have this class is to make mdev/udev create the + * /dev/spidevB.C character device nodes exposing our userspace API. + * It also simplifies memory management. + */ + +static void spidev_classdev_release(struct device *dev) +{ + struct spidev_data *spidev; + + spidev = container_of(dev, struct spidev_data, dev); + kfree(spidev); +} + +static struct class spidev_class = { + .name = "spidev", + .owner = THIS_MODULE, + .dev_release = spidev_classdev_release, +}; + +/*-------------------------------------------------------------------------*/ + +static int spidev_probe(struct spi_device *spi) +{ + struct spidev_data *spidev; + int status; + unsigned long minor; + + /* Allocate driver data */ + spidev = kzalloc(sizeof(*spidev), GFP_KERNEL); + if (!spidev) + return -ENOMEM; + + /* Initialize the driver data */ + spidev->spi = spi; + mutex_init(&spidev->buf_lock); + + INIT_LIST_HEAD(&spidev->device_entry); + + /* If we can allocate a minor number, hook up this device. + * Reusing minors is fine so long as udev or mdev is working. + */ + mutex_lock(&device_list_lock); + minor = find_first_zero_bit(minors, ARRAY_SIZE(minors)); + if (minor < N_SPI_MINORS) { + spidev->dev.parent = &spi->dev; + spidev->dev.class = &spidev_class; + spidev->dev.devt = MKDEV(SPIDEV_MAJOR, minor); + snprintf(spidev->dev.bus_id, sizeof spidev->dev.bus_id, + "spidev%d.%d", + spi->master->bus_num, spi->chip_select); + status = device_register(&spidev->dev); + } else { + dev_dbg(&spi->dev, "no minor number available!\n"); + status = -ENODEV; + } + if (status == 0) { + set_bit(minor, minors); + dev_set_drvdata(&spi->dev, spidev); + list_add(&spidev->device_entry, &device_list); + } + mutex_unlock(&device_list_lock); + + if (status != 0) + kfree(spidev); + + return status; +} + +static int spidev_remove(struct spi_device *spi) +{ + struct spidev_data *spidev = dev_get_drvdata(&spi->dev); + + mutex_lock(&device_list_lock); + + list_del(&spidev->device_entry); + dev_set_drvdata(&spi->dev, NULL); + clear_bit(MINOR(spidev->dev.devt), minors); + device_unregister(&spidev->dev); + + mutex_unlock(&device_list_lock); + + return 0; +} + +static struct spi_driver spidev_spi = { + .driver = { + .name = "spidev", + .owner = THIS_MODULE, + }, + .probe = spidev_probe, + .remove = __devexit_p(spidev_remove), + + /* NOTE: suspend/resume methods are not necessary here. + * We don't do anything except pass the requests to/from + * the underlying controller. The refrigerator handles + * most issues; the controller driver handles the rest. + */ +}; + +/*-------------------------------------------------------------------------*/ + +static int __init spidev_init(void) +{ + int status; + + /* Claim our 256 reserved device numbers. Then register a class + * that will key udev/mdev to add/remove /dev nodes. Last, register + * the driver which manages those device numbers. + */ + BUILD_BUG_ON(N_SPI_MINORS > 256); + status = register_chrdev(SPIDEV_MAJOR, "spi", &spidev_fops); + if (status < 0) + return status; + + status = class_register(&spidev_class); + if (status < 0) { + unregister_chrdev(SPIDEV_MAJOR, spidev_spi.driver.name); + return status; + } + + status = spi_register_driver(&spidev_spi); + if (status < 0) { + class_unregister(&spidev_class); + unregister_chrdev(SPIDEV_MAJOR, spidev_spi.driver.name); + } + return status; +} +module_init(spidev_init); + +static void __exit spidev_exit(void) +{ + spi_unregister_driver(&spidev_spi); + class_unregister(&spidev_class); + unregister_chrdev(SPIDEV_MAJOR, spidev_spi.driver.name); +} +module_exit(spidev_exit); + +MODULE_AUTHOR("Andrea Paterniani, <a.paterniani@swapp-eng.it>"); +MODULE_DESCRIPTION("User mode SPI device interface"); +MODULE_LICENSE("GPL"); |