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Diffstat (limited to 'drivers/spi/spi-atmel.c')
-rw-r--r--drivers/spi/spi-atmel.c292
1 files changed, 273 insertions, 19 deletions
diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c
index a2f40b1b2225..c9eca347787d 100644
--- a/drivers/spi/spi-atmel.c
+++ b/drivers/spi/spi-atmel.c
@@ -41,6 +41,8 @@
#define SPI_CSR1 0x0034
#define SPI_CSR2 0x0038
#define SPI_CSR3 0x003c
+#define SPI_FMR 0x0040
+#define SPI_FLR 0x0044
#define SPI_VERSION 0x00fc
#define SPI_RPR 0x0100
#define SPI_RCR 0x0104
@@ -62,6 +64,14 @@
#define SPI_SWRST_SIZE 1
#define SPI_LASTXFER_OFFSET 24
#define SPI_LASTXFER_SIZE 1
+#define SPI_TXFCLR_OFFSET 16
+#define SPI_TXFCLR_SIZE 1
+#define SPI_RXFCLR_OFFSET 17
+#define SPI_RXFCLR_SIZE 1
+#define SPI_FIFOEN_OFFSET 30
+#define SPI_FIFOEN_SIZE 1
+#define SPI_FIFODIS_OFFSET 31
+#define SPI_FIFODIS_SIZE 1
/* Bitfields in MR */
#define SPI_MSTR_OFFSET 0
@@ -114,6 +124,22 @@
#define SPI_TXEMPTY_SIZE 1
#define SPI_SPIENS_OFFSET 16
#define SPI_SPIENS_SIZE 1
+#define SPI_TXFEF_OFFSET 24
+#define SPI_TXFEF_SIZE 1
+#define SPI_TXFFF_OFFSET 25
+#define SPI_TXFFF_SIZE 1
+#define SPI_TXFTHF_OFFSET 26
+#define SPI_TXFTHF_SIZE 1
+#define SPI_RXFEF_OFFSET 27
+#define SPI_RXFEF_SIZE 1
+#define SPI_RXFFF_OFFSET 28
+#define SPI_RXFFF_SIZE 1
+#define SPI_RXFTHF_OFFSET 29
+#define SPI_RXFTHF_SIZE 1
+#define SPI_TXFPTEF_OFFSET 30
+#define SPI_TXFPTEF_SIZE 1
+#define SPI_RXFPTEF_OFFSET 31
+#define SPI_RXFPTEF_SIZE 1
/* Bitfields in CSR0 */
#define SPI_CPOL_OFFSET 0
@@ -157,6 +183,22 @@
#define SPI_TXTDIS_OFFSET 9
#define SPI_TXTDIS_SIZE 1
+/* Bitfields in FMR */
+#define SPI_TXRDYM_OFFSET 0
+#define SPI_TXRDYM_SIZE 2
+#define SPI_RXRDYM_OFFSET 4
+#define SPI_RXRDYM_SIZE 2
+#define SPI_TXFTHRES_OFFSET 16
+#define SPI_TXFTHRES_SIZE 6
+#define SPI_RXFTHRES_OFFSET 24
+#define SPI_RXFTHRES_SIZE 6
+
+/* Bitfields in FLR */
+#define SPI_TXFL_OFFSET 0
+#define SPI_TXFL_SIZE 6
+#define SPI_RXFL_OFFSET 16
+#define SPI_RXFL_SIZE 6
+
/* Constants for BITS */
#define SPI_BITS_8_BPT 0
#define SPI_BITS_9_BPT 1
@@ -167,6 +209,9 @@
#define SPI_BITS_14_BPT 6
#define SPI_BITS_15_BPT 7
#define SPI_BITS_16_BPT 8
+#define SPI_ONE_DATA 0
+#define SPI_TWO_DATA 1
+#define SPI_FOUR_DATA 2
/* Bit manipulation macros */
#define SPI_BIT(name) \
@@ -185,11 +230,31 @@
__raw_readl((port)->regs + SPI_##reg)
#define spi_writel(port, reg, value) \
__raw_writel((value), (port)->regs + SPI_##reg)
+
+#define spi_readw(port, reg) \
+ __raw_readw((port)->regs + SPI_##reg)
+#define spi_writew(port, reg, value) \
+ __raw_writew((value), (port)->regs + SPI_##reg)
+
+#define spi_readb(port, reg) \
+ __raw_readb((port)->regs + SPI_##reg)
+#define spi_writeb(port, reg, value) \
+ __raw_writeb((value), (port)->regs + SPI_##reg)
#else
#define spi_readl(port, reg) \
readl_relaxed((port)->regs + SPI_##reg)
#define spi_writel(port, reg, value) \
writel_relaxed((value), (port)->regs + SPI_##reg)
+
+#define spi_readw(port, reg) \
+ readw_relaxed((port)->regs + SPI_##reg)
+#define spi_writew(port, reg, value) \
+ writew_relaxed((value), (port)->regs + SPI_##reg)
+
+#define spi_readb(port, reg) \
+ readb_relaxed((port)->regs + SPI_##reg)
+#define spi_writeb(port, reg, value) \
+ writeb_relaxed((value), (port)->regs + SPI_##reg)
#endif
/* use PIO for small transfers, avoiding DMA setup/teardown overhead and
* cache operations; better heuristics consider wordsize and bitrate.
@@ -246,11 +311,14 @@ struct atmel_spi {
bool use_dma;
bool use_pdc;
+ bool use_cs_gpios;
/* dmaengine data */
struct atmel_spi_dma dma;
bool keep_cs;
bool cs_active;
+
+ u32 fifo_size;
};
/* Controller-specific per-slave state */
@@ -321,7 +389,8 @@ static void cs_activate(struct atmel_spi *as, struct spi_device *spi)
}
mr = spi_readl(as, MR);
- gpio_set_value(asd->npcs_pin, active);
+ if (as->use_cs_gpios)
+ gpio_set_value(asd->npcs_pin, active);
} else {
u32 cpol = (spi->mode & SPI_CPOL) ? SPI_BIT(CPOL) : 0;
int i;
@@ -337,7 +406,7 @@ static void cs_activate(struct atmel_spi *as, struct spi_device *spi)
mr = spi_readl(as, MR);
mr = SPI_BFINS(PCS, ~(1 << spi->chip_select), mr);
- if (spi->chip_select != 0)
+ if (as->use_cs_gpios && spi->chip_select != 0)
gpio_set_value(asd->npcs_pin, active);
spi_writel(as, MR, mr);
}
@@ -366,7 +435,9 @@ static void cs_deactivate(struct atmel_spi *as, struct spi_device *spi)
asd->npcs_pin, active ? " (low)" : "",
mr);
- if (atmel_spi_is_v2(as) || spi->chip_select != 0)
+ if (!as->use_cs_gpios)
+ spi_writel(as, CR, SPI_BIT(LASTXFER));
+ else if (atmel_spi_is_v2(as) || spi->chip_select != 0)
gpio_set_value(asd->npcs_pin, !active);
}
@@ -406,6 +477,20 @@ static int atmel_spi_dma_slave_config(struct atmel_spi *as,
slave_config->dst_maxburst = 1;
slave_config->device_fc = false;
+ /*
+ * This driver uses fixed peripheral select mode (PS bit set to '0' in
+ * the Mode Register).
+ * So according to the datasheet, when FIFOs are available (and
+ * enabled), the Transmit FIFO operates in Multiple Data Mode.
+ * In this mode, up to 2 data, not 4, can be written into the Transmit
+ * Data Register in a single access.
+ * However, the first data has to be written into the lowest 16 bits and
+ * the second data into the highest 16 bits of the Transmit
+ * Data Register. For 8bit data (the most frequent case), it would
+ * require to rework tx_buf so each data would actualy fit 16 bits.
+ * So we'd rather write only one data at the time. Hence the transmit
+ * path works the same whether FIFOs are available (and enabled) or not.
+ */
slave_config->direction = DMA_MEM_TO_DEV;
if (dmaengine_slave_config(as->dma.chan_tx, slave_config)) {
dev_err(&as->pdev->dev,
@@ -413,6 +498,14 @@ static int atmel_spi_dma_slave_config(struct atmel_spi *as,
err = -EINVAL;
}
+ /*
+ * This driver configures the spi controller for master mode (MSTR bit
+ * set to '1' in the Mode Register).
+ * So according to the datasheet, when FIFOs are available (and
+ * enabled), the Receive FIFO operates in Single Data Mode.
+ * So the receive path works the same whether FIFOs are available (and
+ * enabled) or not.
+ */
slave_config->direction = DMA_DEV_TO_MEM;
if (dmaengine_slave_config(as->dma.chan_rx, slave_config)) {
dev_err(&as->pdev->dev,
@@ -502,10 +595,10 @@ static void dma_callback(void *data)
}
/*
- * Next transfer using PIO.
+ * Next transfer using PIO without FIFO.
*/
-static void atmel_spi_next_xfer_pio(struct spi_master *master,
- struct spi_transfer *xfer)
+static void atmel_spi_next_xfer_single(struct spi_master *master,
+ struct spi_transfer *xfer)
{
struct atmel_spi *as = spi_master_get_devdata(master);
unsigned long xfer_pos = xfer->len - as->current_remaining_bytes;
@@ -538,6 +631,99 @@ static void atmel_spi_next_xfer_pio(struct spi_master *master,
}
/*
+ * Next transfer using PIO with FIFO.
+ */
+static void atmel_spi_next_xfer_fifo(struct spi_master *master,
+ struct spi_transfer *xfer)
+{
+ struct atmel_spi *as = spi_master_get_devdata(master);
+ u32 current_remaining_data, num_data;
+ u32 offset = xfer->len - as->current_remaining_bytes;
+ const u16 *words = (const u16 *)((u8 *)xfer->tx_buf + offset);
+ const u8 *bytes = (const u8 *)((u8 *)xfer->tx_buf + offset);
+ u16 td0, td1;
+ u32 fifomr;
+
+ dev_vdbg(master->dev.parent, "atmel_spi_next_xfer_fifo\n");
+
+ /* Compute the number of data to transfer in the current iteration */
+ current_remaining_data = ((xfer->bits_per_word > 8) ?
+ ((u32)as->current_remaining_bytes >> 1) :
+ (u32)as->current_remaining_bytes);
+ num_data = min(current_remaining_data, as->fifo_size);
+
+ /* Flush RX and TX FIFOs */
+ spi_writel(as, CR, SPI_BIT(RXFCLR) | SPI_BIT(TXFCLR));
+ while (spi_readl(as, FLR))
+ cpu_relax();
+
+ /* Set RX FIFO Threshold to the number of data to transfer */
+ fifomr = spi_readl(as, FMR);
+ spi_writel(as, FMR, SPI_BFINS(RXFTHRES, num_data, fifomr));
+
+ /* Clear FIFO flags in the Status Register, especially RXFTHF */
+ (void)spi_readl(as, SR);
+
+ /* Fill TX FIFO */
+ while (num_data >= 2) {
+ if (xfer->tx_buf) {
+ if (xfer->bits_per_word > 8) {
+ td0 = *words++;
+ td1 = *words++;
+ } else {
+ td0 = *bytes++;
+ td1 = *bytes++;
+ }
+ } else {
+ td0 = 0;
+ td1 = 0;
+ }
+
+ spi_writel(as, TDR, (td1 << 16) | td0);
+ num_data -= 2;
+ }
+
+ if (num_data) {
+ if (xfer->tx_buf) {
+ if (xfer->bits_per_word > 8)
+ td0 = *words++;
+ else
+ td0 = *bytes++;
+ } else {
+ td0 = 0;
+ }
+
+ spi_writew(as, TDR, td0);
+ num_data--;
+ }
+
+ dev_dbg(master->dev.parent,
+ " start fifo xfer %p: len %u tx %p rx %p bitpw %d\n",
+ xfer, xfer->len, xfer->tx_buf, xfer->rx_buf,
+ xfer->bits_per_word);
+
+ /*
+ * Enable RX FIFO Threshold Flag interrupt to be notified about
+ * transfer completion.
+ */
+ spi_writel(as, IER, SPI_BIT(RXFTHF) | SPI_BIT(OVRES));
+}
+
+/*
+ * Next transfer using PIO.
+ */
+static void atmel_spi_next_xfer_pio(struct spi_master *master,
+ struct spi_transfer *xfer)
+{
+ struct atmel_spi *as = spi_master_get_devdata(master);
+
+ if (as->fifo_size)
+ atmel_spi_next_xfer_fifo(master, xfer);
+ else
+ atmel_spi_next_xfer_single(master, xfer);
+}
+
+/*
* Submit next transfer for DMA.
*/
static int atmel_spi_next_xfer_dma_submit(struct spi_master *master,
@@ -839,13 +1025,8 @@ static void atmel_spi_disable_pdc_transfer(struct atmel_spi *as)
spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS));
}
-/* Called from IRQ
- *
- * Must update "current_remaining_bytes" to keep track of data
- * to transfer.
- */
static void
-atmel_spi_pump_pio_data(struct atmel_spi *as, struct spi_transfer *xfer)
+atmel_spi_pump_single_data(struct atmel_spi *as, struct spi_transfer *xfer)
{
u8 *rxp;
u16 *rxp16;
@@ -872,6 +1053,57 @@ atmel_spi_pump_pio_data(struct atmel_spi *as, struct spi_transfer *xfer)
}
}
+static void
+atmel_spi_pump_fifo_data(struct atmel_spi *as, struct spi_transfer *xfer)
+{
+ u32 fifolr = spi_readl(as, FLR);
+ u32 num_bytes, num_data = SPI_BFEXT(RXFL, fifolr);
+ u32 offset = xfer->len - as->current_remaining_bytes;
+ u16 *words = (u16 *)((u8 *)xfer->rx_buf + offset);
+ u8 *bytes = (u8 *)((u8 *)xfer->rx_buf + offset);
+ u16 rd; /* RD field is the lowest 16 bits of RDR */
+
+ /* Update the number of remaining bytes to transfer */
+ num_bytes = ((xfer->bits_per_word > 8) ?
+ (num_data << 1) :
+ num_data);
+
+ if (as->current_remaining_bytes > num_bytes)
+ as->current_remaining_bytes -= num_bytes;
+ else
+ as->current_remaining_bytes = 0;
+
+ /* Handle odd number of bytes when data are more than 8bit width */
+ if (xfer->bits_per_word > 8)
+ as->current_remaining_bytes &= ~0x1;
+
+ /* Read data */
+ while (num_data) {
+ rd = spi_readl(as, RDR);
+ if (xfer->rx_buf) {
+ if (xfer->bits_per_word > 8)
+ *words++ = rd;
+ else
+ *bytes++ = rd;
+ }
+ num_data--;
+ }
+}
+
+/* Called from IRQ
+ *
+ * Must update "current_remaining_bytes" to keep track of data
+ * to transfer.
+ */
+static void
+atmel_spi_pump_pio_data(struct atmel_spi *as, struct spi_transfer *xfer)
+{
+ if (as->fifo_size)
+ atmel_spi_pump_fifo_data(as, xfer);
+ else
+ atmel_spi_pump_single_data(as, xfer);
+}
+
/* Interrupt
*
* No need for locking in this Interrupt handler: done_status is the
@@ -912,7 +1144,7 @@ atmel_spi_pio_interrupt(int irq, void *dev_id)
complete(&as->xfer_completion);
- } else if (pending & SPI_BIT(RDRF)) {
+ } else if (pending & (SPI_BIT(RDRF) | SPI_BIT(RXFTHF))) {
atmel_spi_lock(as);
if (as->current_remaining_bytes) {
@@ -996,6 +1228,8 @@ static int atmel_spi_setup(struct spi_device *spi)
csr |= SPI_BIT(CPOL);
if (!(spi->mode & SPI_CPHA))
csr |= SPI_BIT(NCPHA);
+ if (!as->use_cs_gpios)
+ csr |= SPI_BIT(CSAAT);
/* DLYBS is mostly irrelevant since we manage chipselect using GPIOs.
*
@@ -1009,7 +1243,9 @@ static int atmel_spi_setup(struct spi_device *spi)
/* chipselect must have been muxed as GPIO (e.g. in board setup) */
npcs_pin = (unsigned long)spi->controller_data;
- if (gpio_is_valid(spi->cs_gpio))
+ if (!as->use_cs_gpios)
+ npcs_pin = spi->chip_select;
+ else if (gpio_is_valid(spi->cs_gpio))
npcs_pin = spi->cs_gpio;
asd = spi->controller_state;
@@ -1018,15 +1254,19 @@ static int atmel_spi_setup(struct spi_device *spi)
if (!asd)
return -ENOMEM;
- ret = gpio_request(npcs_pin, dev_name(&spi->dev));
- if (ret) {
- kfree(asd);
- return ret;
+ if (as->use_cs_gpios) {
+ ret = gpio_request(npcs_pin, dev_name(&spi->dev));
+ if (ret) {
+ kfree(asd);
+ return ret;
+ }
+
+ gpio_direction_output(npcs_pin,
+ !(spi->mode & SPI_CS_HIGH));
}
asd->npcs_pin = npcs_pin;
spi->controller_state = asd;
- gpio_direction_output(npcs_pin, !(spi->mode & SPI_CS_HIGH));
}
asd->csr = csr;
@@ -1338,6 +1578,13 @@ static int atmel_spi_probe(struct platform_device *pdev)
atmel_get_caps(as);
+ as->use_cs_gpios = true;
+ if (atmel_spi_is_v2(as) &&
+ !of_get_property(pdev->dev.of_node, "cs-gpios", NULL)) {
+ as->use_cs_gpios = false;
+ master->num_chipselect = 4;
+ }
+
as->use_dma = false;
as->use_pdc = false;
if (as->caps.has_dma_support) {
@@ -1380,6 +1627,13 @@ static int atmel_spi_probe(struct platform_device *pdev)
spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS));
spi_writel(as, CR, SPI_BIT(SPIEN));
+ as->fifo_size = 0;
+ if (!of_property_read_u32(pdev->dev.of_node, "atmel,fifo-size",
+ &as->fifo_size)) {
+ dev_info(&pdev->dev, "Using FIFO (%u data)\n", as->fifo_size);
+ spi_writel(as, CR, SPI_BIT(FIFOEN));
+ }
+
/* go! */
dev_info(&pdev->dev, "Atmel SPI Controller at 0x%08lx (irq %d)\n",
(unsigned long)regs->start, irq);
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