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path: root/drivers/spi/spi-s3c64xx.c
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Diffstat (limited to 'drivers/spi/spi-s3c64xx.c')
-rw-r--r--drivers/spi/spi-s3c64xx.c207
1 files changed, 145 insertions, 62 deletions
diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index 71cc3e6ef47c..eb53df27e7ea 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -39,6 +39,7 @@
#endif
#define MAX_SPI_PORTS 3
+#define S3C64XX_SPI_QUIRK_POLL (1 << 0)
/* Registers and bit-fields */
@@ -130,6 +131,7 @@
#define S3C64XX_SPI_TRAILCNT S3C64XX_SPI_MAX_TRAILCNT
#define msecs_to_loops(t) (loops_per_jiffy / 1000 * HZ * t)
+#define is_polling(x) (x->port_conf->quirks & S3C64XX_SPI_QUIRK_POLL)
#define RXBUSY (1<<2)
#define TXBUSY (1<<3)
@@ -158,6 +160,7 @@ struct s3c64xx_spi_port_config {
int fifo_lvl_mask[MAX_SPI_PORTS];
int rx_lvl_offset;
int tx_st_done;
+ int quirks;
bool high_speed;
bool clk_from_cmu;
};
@@ -205,6 +208,7 @@ struct s3c64xx_spi_driver_data {
struct s3c64xx_spi_port_config *port_conf;
unsigned int port_id;
unsigned long gpios[4];
+ bool cs_gpio;
};
static void flush_fifo(struct s3c64xx_spi_driver_data *sdd)
@@ -344,8 +348,12 @@ static int s3c64xx_spi_prepare_transfer(struct spi_master *spi)
{
struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(spi);
- /* Acquire DMA channels */
- while (!acquire_dma(sdd))
+ /*
+ * If DMA resource was not available during
+ * probe, no need to continue with dma requests
+ * else Acquire DMA channels
+ */
+ while (!is_polling(sdd) && !acquire_dma(sdd))
usleep_range(10000, 11000);
pm_runtime_get_sync(&sdd->pdev->dev);
@@ -358,9 +366,12 @@ static int s3c64xx_spi_unprepare_transfer(struct spi_master *spi)
struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(spi);
/* Free DMA channels */
- sdd->ops->release((enum dma_ch)sdd->rx_dma.ch, &s3c64xx_spi_dma_client);
- sdd->ops->release((enum dma_ch)sdd->tx_dma.ch, &s3c64xx_spi_dma_client);
-
+ if (!is_polling(sdd)) {
+ sdd->ops->release((enum dma_ch)sdd->rx_dma.ch,
+ &s3c64xx_spi_dma_client);
+ sdd->ops->release((enum dma_ch)sdd->tx_dma.ch,
+ &s3c64xx_spi_dma_client);
+ }
pm_runtime_put(&sdd->pdev->dev);
return 0;
@@ -464,8 +475,10 @@ static int s3c64xx_spi_unprepare_transfer(struct spi_master *spi)
struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(spi);
/* Free DMA channels */
- dma_release_channel(sdd->rx_dma.ch);
- dma_release_channel(sdd->tx_dma.ch);
+ if (!is_polling(sdd)) {
+ dma_release_channel(sdd->rx_dma.ch);
+ dma_release_channel(sdd->tx_dma.ch);
+ }
pm_runtime_put(&sdd->pdev->dev);
return 0;
@@ -558,14 +571,40 @@ static inline void enable_cs(struct s3c64xx_spi_driver_data *sdd,
if (sdd->tgl_spi != spi) { /* if last mssg on diff device */
/* Deselect the last toggled device */
cs = sdd->tgl_spi->controller_data;
- gpio_set_value(cs->line,
- spi->mode & SPI_CS_HIGH ? 0 : 1);
+ if (sdd->cs_gpio)
+ gpio_set_value(cs->line,
+ spi->mode & SPI_CS_HIGH ? 0 : 1);
}
sdd->tgl_spi = NULL;
}
cs = spi->controller_data;
- gpio_set_value(cs->line, spi->mode & SPI_CS_HIGH ? 1 : 0);
+ if (sdd->cs_gpio)
+ gpio_set_value(cs->line, spi->mode & SPI_CS_HIGH ? 1 : 0);
+
+ /* Start the signals */
+ writel(0, sdd->regs + S3C64XX_SPI_SLAVE_SEL);
+}
+
+static u32 s3c64xx_spi_wait_for_timeout(struct s3c64xx_spi_driver_data *sdd,
+ int timeout_ms)
+{
+ void __iomem *regs = sdd->regs;
+ unsigned long val = 1;
+ u32 status;
+
+ /* max fifo depth available */
+ u32 max_fifo = (FIFO_LVL_MASK(sdd) >> 1) + 1;
+
+ if (timeout_ms)
+ val = msecs_to_loops(timeout_ms);
+
+ do {
+ status = readl(regs + S3C64XX_SPI_STATUS);
+ } while (RX_FIFO_LVL(status, sdd) < max_fifo && --val);
+
+ /* return the actual received data length */
+ return RX_FIFO_LVL(status, sdd);
}
static int wait_for_xfer(struct s3c64xx_spi_driver_data *sdd,
@@ -590,20 +629,19 @@ static int wait_for_xfer(struct s3c64xx_spi_driver_data *sdd,
} while (RX_FIFO_LVL(status, sdd) < xfer->len && --val);
}
- if (!val)
- return -EIO;
-
if (dma_mode) {
u32 status;
/*
+ * If the previous xfer was completed within timeout, then
+ * proceed further else return -EIO.
* DmaTx returns after simply writing data in the FIFO,
* w/o waiting for real transmission on the bus to finish.
* DmaRx returns only after Dma read data from FIFO which
* needs bus transmission to finish, so we don't worry if
* Xfer involved Rx(with or without Tx).
*/
- if (xfer->rx_buf == NULL) {
+ if (val && !xfer->rx_buf) {
val = msecs_to_loops(10);
status = readl(regs + S3C64XX_SPI_STATUS);
while ((TX_FIFO_LVL(status, sdd)
@@ -613,30 +651,54 @@ static int wait_for_xfer(struct s3c64xx_spi_driver_data *sdd,
status = readl(regs + S3C64XX_SPI_STATUS);
}
- if (!val)
- return -EIO;
}
+
+ /* If timed out while checking rx/tx status return error */
+ if (!val)
+ return -EIO;
} else {
+ int loops;
+ u32 cpy_len;
+ u8 *buf;
+
/* If it was only Tx */
- if (xfer->rx_buf == NULL) {
+ if (!xfer->rx_buf) {
sdd->state &= ~TXBUSY;
return 0;
}
- switch (sdd->cur_bpw) {
- case 32:
- ioread32_rep(regs + S3C64XX_SPI_RX_DATA,
- xfer->rx_buf, xfer->len / 4);
- break;
- case 16:
- ioread16_rep(regs + S3C64XX_SPI_RX_DATA,
- xfer->rx_buf, xfer->len / 2);
- break;
- default:
- ioread8_rep(regs + S3C64XX_SPI_RX_DATA,
- xfer->rx_buf, xfer->len);
- break;
- }
+ /*
+ * If the receive length is bigger than the controller fifo
+ * size, calculate the loops and read the fifo as many times.
+ * loops = length / max fifo size (calculated by using the
+ * fifo mask).
+ * For any size less than the fifo size the below code is
+ * executed atleast once.
+ */
+ loops = xfer->len / ((FIFO_LVL_MASK(sdd) >> 1) + 1);
+ buf = xfer->rx_buf;
+ do {
+ /* wait for data to be received in the fifo */
+ cpy_len = s3c64xx_spi_wait_for_timeout(sdd,
+ (loops ? ms : 0));
+
+ switch (sdd->cur_bpw) {
+ case 32:
+ ioread32_rep(regs + S3C64XX_SPI_RX_DATA,
+ buf, cpy_len / 4);
+ break;
+ case 16:
+ ioread16_rep(regs + S3C64XX_SPI_RX_DATA,
+ buf, cpy_len / 2);
+ break;
+ default:
+ ioread8_rep(regs + S3C64XX_SPI_RX_DATA,
+ buf, cpy_len);
+ break;
+ }
+
+ buf = buf + cpy_len;
+ } while (loops--);
sdd->state &= ~RXBUSY;
}
@@ -651,7 +713,11 @@ static inline void disable_cs(struct s3c64xx_spi_driver_data *sdd,
if (sdd->tgl_spi == spi)
sdd->tgl_spi = NULL;
- gpio_set_value(cs->line, spi->mode & SPI_CS_HIGH ? 0 : 1);
+ if (sdd->cs_gpio)
+ gpio_set_value(cs->line, spi->mode & SPI_CS_HIGH ? 0 : 1);
+
+ /* Quiese the signals */
+ writel(S3C64XX_SPI_SLAVE_SIG_INACT, sdd->regs + S3C64XX_SPI_SLAVE_SEL);
}
static void s3c64xx_spi_config(struct s3c64xx_spi_driver_data *sdd)
@@ -733,7 +799,7 @@ static int s3c64xx_spi_map_mssg(struct s3c64xx_spi_driver_data *sdd,
struct device *dev = &sdd->pdev->dev;
struct spi_transfer *xfer;
- if (msg->is_dma_mapped)
+ if (is_polling(sdd) || msg->is_dma_mapped)
return 0;
/* First mark all xfer unmapped */
@@ -782,7 +848,7 @@ static void s3c64xx_spi_unmap_mssg(struct s3c64xx_spi_driver_data *sdd,
struct device *dev = &sdd->pdev->dev;
struct spi_transfer *xfer;
- if (msg->is_dma_mapped)
+ if (is_polling(sdd) || msg->is_dma_mapped)
return;
list_for_each_entry(xfer, &msg->transfers, transfer_list) {
@@ -861,8 +927,9 @@ static int s3c64xx_spi_transfer_one_message(struct spi_master *master,
/* Polling method for xfers not bigger than FIFO capacity */
use_dma = 0;
- if (sdd->rx_dma.ch && sdd->tx_dma.ch &&
- (xfer->len > ((FIFO_LVL_MASK(sdd) >> 1) + 1)))
+ if (!is_polling(sdd) &&
+ (sdd->rx_dma.ch && sdd->tx_dma.ch &&
+ (xfer->len > ((FIFO_LVL_MASK(sdd) >> 1) + 1))))
use_dma = 1;
spin_lock_irqsave(&sdd->lock, flags);
@@ -876,17 +943,10 @@ static int s3c64xx_spi_transfer_one_message(struct spi_master *master,
/* Slave Select */
enable_cs(sdd, spi);
- /* Start the signals */
- writel(0, sdd->regs + S3C64XX_SPI_SLAVE_SEL);
-
spin_unlock_irqrestore(&sdd->lock, flags);
status = wait_for_xfer(sdd, xfer, use_dma);
- /* Quiese the signals */
- writel(S3C64XX_SPI_SLAVE_SIG_INACT,
- sdd->regs + S3C64XX_SPI_SLAVE_SEL);
-
if (status) {
dev_err(&spi->dev, "I/O Error: rx-%d tx-%d res:rx-%c tx-%c len-%d\n",
xfer->rx_buf ? 1 : 0, xfer->tx_buf ? 1 : 0,
@@ -942,8 +1002,10 @@ static struct s3c64xx_spi_csinfo *s3c64xx_get_slave_ctrldata(
{
struct s3c64xx_spi_csinfo *cs;
struct device_node *slave_np, *data_np = NULL;
+ struct s3c64xx_spi_driver_data *sdd;
u32 fb_delay = 0;
+ sdd = spi_master_get_devdata(spi->master);
slave_np = spi->dev.of_node;
if (!slave_np) {
dev_err(&spi->dev, "device node not found\n");
@@ -963,7 +1025,10 @@ static struct s3c64xx_spi_csinfo *s3c64xx_get_slave_ctrldata(
return ERR_PTR(-ENOMEM);
}
- cs->line = of_get_named_gpio(data_np, "cs-gpio", 0);
+ /* The CS line is asserted/deasserted by the gpio pin */
+ if (sdd->cs_gpio)
+ cs->line = of_get_named_gpio(data_np, "cs-gpio", 0);
+
if (!gpio_is_valid(cs->line)) {
dev_err(&spi->dev, "chip select gpio is not specified or invalid\n");
kfree(cs);
@@ -1003,7 +1068,8 @@ static int s3c64xx_spi_setup(struct spi_device *spi)
return -ENODEV;
}
- if (!spi_get_ctldata(spi)) {
+ /* Request gpio only if cs line is asserted by gpio pins */
+ if (sdd->cs_gpio) {
err = gpio_request_one(cs->line, GPIOF_OUT_INIT_HIGH,
dev_name(&spi->dev));
if (err) {
@@ -1012,9 +1078,11 @@ static int s3c64xx_spi_setup(struct spi_device *spi)
cs->line, err);
goto err_gpio_req;
}
- spi_set_ctldata(spi, cs);
}
+ if (!spi_get_ctldata(spi))
+ spi_set_ctldata(spi, cs);
+
sci = sdd->cntrlr_info;
spin_lock_irqsave(&sdd->lock, flags);
@@ -1092,8 +1160,10 @@ err_gpio_req:
static void s3c64xx_spi_cleanup(struct spi_device *spi)
{
struct s3c64xx_spi_csinfo *cs = spi_get_ctldata(spi);
+ struct s3c64xx_spi_driver_data *sdd;
- if (cs) {
+ sdd = spi_master_get_devdata(spi->master);
+ if (cs && sdd->cs_gpio) {
gpio_free(cs->line);
if (spi->dev.of_node)
kfree(cs);
@@ -1270,7 +1340,11 @@ static int s3c64xx_spi_probe(struct platform_device *pdev)
sdd->cntrlr_info = sci;
sdd->pdev = pdev;
sdd->sfr_start = mem_res->start;
+ sdd->cs_gpio = true;
if (pdev->dev.of_node) {
+ if (!of_find_property(pdev->dev.of_node, "cs-gpio", NULL))
+ sdd->cs_gpio = false;
+
ret = of_alias_get_id(pdev->dev.of_node, "spi");
if (ret < 0) {
dev_err(&pdev->dev, "failed to get alias id, errno %d\n",
@@ -1287,19 +1361,19 @@ static int s3c64xx_spi_probe(struct platform_device *pdev)
if (!sdd->pdev->dev.of_node) {
res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
if (!res) {
- dev_err(&pdev->dev, "Unable to get SPI tx dma "
- "resource\n");
- return -ENXIO;
- }
- sdd->tx_dma.dmach = res->start;
+ dev_warn(&pdev->dev, "Unable to get SPI tx dma "
+ "resource. Switching to poll mode\n");
+ sdd->port_conf->quirks = S3C64XX_SPI_QUIRK_POLL;
+ } else
+ sdd->tx_dma.dmach = res->start;
res = platform_get_resource(pdev, IORESOURCE_DMA, 1);
if (!res) {
- dev_err(&pdev->dev, "Unable to get SPI rx dma "
- "resource\n");
- return -ENXIO;
- }
- sdd->rx_dma.dmach = res->start;
+ dev_warn(&pdev->dev, "Unable to get SPI rx dma "
+ "resource. Switching to poll mode\n");
+ sdd->port_conf->quirks = S3C64XX_SPI_QUIRK_POLL;
+ } else
+ sdd->rx_dma.dmach = res->start;
}
sdd->tx_dma.direction = DMA_MEM_TO_DEV;
@@ -1314,7 +1388,8 @@ static int s3c64xx_spi_probe(struct platform_device *pdev)
master->unprepare_transfer_hardware = s3c64xx_spi_unprepare_transfer;
master->num_chipselect = sci->num_cs;
master->dma_alignment = 8;
- master->bits_per_word_mask = BIT(32 - 1) | BIT(16 - 1) | BIT(8 - 1);
+ master->bits_per_word_mask = SPI_BPW_MASK(32) | SPI_BPW_MASK(16) |
+ SPI_BPW_MASK(8);
/* the spi->mode bits understood by this driver: */
master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
@@ -1399,7 +1474,6 @@ err3:
err2:
clk_disable_unprepare(sdd->clk);
err0:
- platform_set_drvdata(pdev, NULL);
spi_master_put(master);
return ret;
@@ -1420,7 +1494,6 @@ static int s3c64xx_spi_remove(struct platform_device *pdev)
clk_disable_unprepare(sdd->clk);
- platform_set_drvdata(pdev, NULL);
spi_master_put(master);
return 0;
@@ -1535,6 +1608,15 @@ static struct s3c64xx_spi_port_config exynos4_spi_port_config = {
.clk_from_cmu = true,
};
+static struct s3c64xx_spi_port_config exynos5440_spi_port_config = {
+ .fifo_lvl_mask = { 0x1ff },
+ .rx_lvl_offset = 15,
+ .tx_st_done = 25,
+ .high_speed = true,
+ .clk_from_cmu = true,
+ .quirks = S3C64XX_SPI_QUIRK_POLL,
+};
+
static struct platform_device_id s3c64xx_spi_driver_ids[] = {
{
.name = "s3c2443-spi",
@@ -1558,15 +1640,16 @@ static struct platform_device_id s3c64xx_spi_driver_ids[] = {
{ },
};
-#ifdef CONFIG_OF
static const struct of_device_id s3c64xx_spi_dt_match[] = {
{ .compatible = "samsung,exynos4210-spi",
.data = (void *)&exynos4_spi_port_config,
},
+ { .compatible = "samsung,exynos5440-spi",
+ .data = (void *)&exynos5440_spi_port_config,
+ },
{ },
};
MODULE_DEVICE_TABLE(of, s3c64xx_spi_dt_match);
-#endif /* CONFIG_OF */
static struct platform_driver s3c64xx_spi_driver = {
.driver = {
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-28 05:04:57 +0000