diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/spi/Kconfig | 4 | ||||
| -rw-r--r-- | drivers/spi/spi-bitbang.c | 23 | ||||
| -rw-r--r-- | drivers/spi/spi-dw-core.c | 20 | ||||
| -rw-r--r-- | drivers/spi/spi-dw-mmio.c | 8 | ||||
| -rw-r--r-- | drivers/spi/spi-dw.h | 2 |
5 files changed, 33 insertions, 24 deletions
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig index e2d2f011f973..a2c99ff33e0a 100644 --- a/drivers/spi/Kconfig +++ b/drivers/spi/Kconfig @@ -226,11 +226,11 @@ config SPI_BCMBCA_HSSPI explicitly. config SPI_BITBANG - tristate "Utilities for Bitbanging SPI masters" + tristate "Utilities for Bitbanging SPI host controllers" help With a few GPIO pins, your system can bitbang the SPI protocol. Select this to get SPI support through I/O pins (GPIO, parallel - port, etc). Or, some systems' SPI master controller drivers use + port, etc). Or, some systems' SPI host controller drivers use this code to manage the per-word or per-transfer accesses to the hardware shift registers. diff --git a/drivers/spi/spi-bitbang.c b/drivers/spi/spi-bitbang.c index a0e2204fc039..ca5cc67555c5 100644 --- a/drivers/spi/spi-bitbang.c +++ b/drivers/spi/spi-bitbang.c @@ -1,6 +1,6 @@ // SPDX-License-Identifier: GPL-2.0-or-later /* - * polling/bitbanging SPI master controller driver utilities + * Polling/bitbanging SPI host controller controller driver utilities */ #include <linux/spinlock.h> @@ -11,6 +11,7 @@ #include <linux/errno.h> #include <linux/platform_device.h> #include <linux/slab.h> +#include <linux/time64.h> #include <linux/spi/spi.h> #include <linux/spi/spi_bitbang.h> @@ -168,8 +169,8 @@ int spi_bitbang_setup_transfer(struct spi_device *spi, struct spi_transfer *t) if (!hz) hz = spi->max_speed_hz; if (hz) { - cs->nsecs = (1000000000/2) / hz; - if (cs->nsecs > (MAX_UDELAY_MS * 1000 * 1000)) + cs->nsecs = (NSEC_PER_SEC / 2) / hz; + if (cs->nsecs > (MAX_UDELAY_MS * NSEC_PER_MSEC)) return -EINVAL; } @@ -393,12 +394,12 @@ int spi_bitbang_init(struct spi_bitbang *bitbang) EXPORT_SYMBOL_GPL(spi_bitbang_init); /** - * spi_bitbang_start - start up a polled/bitbanging SPI master driver + * spi_bitbang_start - start up a polled/bitbanging SPI host controller driver * @bitbang: driver handle * * Caller should have zero-initialized all parts of the structure, and then - * provided callbacks for chip selection and I/O loops. If the master has - * a transfer method, its final step should call spi_bitbang_transfer; or, + * provided callbacks for chip selection and I/O loops. If the host controller has + * a transfer method, its final step should call spi_bitbang_transfer(); or, * that's the default if the transfer routine is not initialized. It should * also set up the bus number and number of chipselects. * @@ -406,9 +407,9 @@ EXPORT_SYMBOL_GPL(spi_bitbang_init); * hardware that basically exposes a shift register) or per-spi_transfer * (which takes better advantage of hardware like fifos or DMA engines). * - * Drivers using per-word I/O loops should use (or call) spi_bitbang_setup, - * spi_bitbang_cleanup and spi_bitbang_setup_transfer to handle those spi - * master methods. Those methods are the defaults if the bitbang->txrx_bufs + * Drivers using per-word I/O loops should use (or call) spi_bitbang_setup(), + * spi_bitbang_cleanup() and spi_bitbang_setup_transfer() to handle those SPI + * host controller methods. Those methods are the defaults if the bitbang->txrx_bufs * routine isn't initialized. * * This routine registers the spi_controller, which will process requests in a @@ -417,7 +418,7 @@ EXPORT_SYMBOL_GPL(spi_bitbang_init); * * On success, this routine will take a reference to the controller. The caller * is responsible for calling spi_bitbang_stop() to decrement the reference and - * spi_controller_put() as counterpart of spi_alloc_master() to prevent a memory + * spi_controller_put() as counterpart of spi_alloc_host() to prevent a memory * leak. */ int spi_bitbang_start(struct spi_bitbang *bitbang) @@ -450,4 +451,4 @@ void spi_bitbang_stop(struct spi_bitbang *bitbang) EXPORT_SYMBOL_GPL(spi_bitbang_stop); MODULE_LICENSE("GPL"); - +MODULE_DESCRIPTION("Utilities for Bitbanging SPI host controllers"); diff --git a/drivers/spi/spi-dw-core.c b/drivers/spi/spi-dw-core.c index 0274c9295514..ddfdb903047a 100644 --- a/drivers/spi/spi-dw-core.c +++ b/drivers/spi/spi-dw-core.c @@ -6,6 +6,7 @@ */ #include <linux/bitfield.h> +#include <linux/bitops.h> #include <linux/dma-mapping.h> #include <linux/interrupt.h> #include <linux/module.h> @@ -421,10 +422,7 @@ static int dw_spi_transfer_one(struct spi_controller *host, int ret; dws->dma_mapped = 0; - dws->n_bytes = - roundup_pow_of_two(DIV_ROUND_UP(transfer->bits_per_word, - BITS_PER_BYTE)); - + dws->n_bytes = roundup_pow_of_two(BITS_TO_BYTES(transfer->bits_per_word)); dws->tx = (void *)transfer->tx_buf; dws->tx_len = transfer->len / dws->n_bytes; dws->rx = transfer->rx_buf; @@ -837,6 +835,20 @@ static void dw_spi_hw_init(struct device *dev, struct dw_spi *dws) } /* + * Try to detect the number of native chip-selects if the platform + * driver didn't set it up. There can be up to 16 lines configured. + */ + if (!dws->num_cs) { + u32 ser; + + dw_writel(dws, DW_SPI_SER, 0xffff); + ser = dw_readl(dws, DW_SPI_SER); + dw_writel(dws, DW_SPI_SER, 0); + + dws->num_cs = hweight16(ser); + } + + /* * Try to detect the FIFO depth if not set by interface driver, * the depth could be from 2 to 256 from HW spec */ diff --git a/drivers/spi/spi-dw-mmio.c b/drivers/spi/spi-dw-mmio.c index cc74cbe03431..c56de35eca98 100644 --- a/drivers/spi/spi-dw-mmio.c +++ b/drivers/spi/spi-dw-mmio.c @@ -320,7 +320,6 @@ static int dw_spi_mmio_probe(struct platform_device *pdev) struct resource *mem; struct dw_spi *dws; int ret; - int num_cs; dwsmmio = devm_kzalloc(&pdev->dev, sizeof(struct dw_spi_mmio), GFP_KERNEL); @@ -364,11 +363,8 @@ static int dw_spi_mmio_probe(struct platform_device *pdev) &dws->reg_io_width)) dws->reg_io_width = 4; - num_cs = 4; - - device_property_read_u32(&pdev->dev, "num-cs", &num_cs); - - dws->num_cs = num_cs; + /* Rely on the auto-detection if no property specified */ + device_property_read_u32(&pdev->dev, "num-cs", &dws->num_cs); init_func = device_get_match_data(&pdev->dev); if (init_func) { diff --git a/drivers/spi/spi-dw.h b/drivers/spi/spi-dw.h index 6cafeee8ee2a..fc267c6437ae 100644 --- a/drivers/spi/spi-dw.h +++ b/drivers/spi/spi-dw.h @@ -164,8 +164,8 @@ struct dw_spi { u32 max_freq; /* max bus freq supported */ u32 reg_io_width; /* DR I/O width in bytes */ + u32 num_cs; /* chip select lines */ u16 bus_num; - u16 num_cs; /* supported slave numbers */ void (*set_cs)(struct spi_device *spi, bool enable); /* Current message transfer state info */ |