This patch series adds support for the polling mode only. Also 2nd patch
in the series adds support for dedicated cs pin. After Thomas's patch for
using default gpio is merged(commit id: 00ab539), one of the patch in this
series is dropped and new series is generated.
Girish K S (3):
spi: s3c64xx: added support for polling mode
spi: s3c64xx: Added provision for dedicated cs pin
spi: s3c64xx: Added support for exynos5440 spi
drivers/spi/spi-s3c64xx.c | 192 +++++++++++++++++++++++++++++++-------------
1 files changed, 135 insertions(+), 57 deletions(-)
--
1.7.5.4
From: Girish K S <[email protected]>
The 64xx spi driver supports partial polling mode.
Only the last chunk of the transfer length is transferred
or recieved in polling mode.
Some SoC's that adopt this controller might not have have dma
interface. This patch adds support for complete polling mode
and gives flexibity for the user to select poll/dma mode.
Signed-off-by: Girish K S <[email protected]>
---
drivers/spi/spi-s3c64xx.c | 150 ++++++++++++++++++++++++++++++---------------
1 files changed, 101 insertions(+), 49 deletions(-)
diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index 5000586..665fe2b 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;
};
@@ -344,8 +347,12 @@ 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 +365,12 @@ 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 +474,10 @@ 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;
@@ -566,6 +578,27 @@ static inline void enable_cs(struct s3c64xx_spi_driver_data *sdd,
cs = spi->controller_data;
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 wait_for_timeout(struct s3c64xx_spi_driver_data *sdd,
+ int timeout_ms)
+{
+ void __iomem *regs = sdd->regs;
+ unsigned long val;
+ u32 status;
+ /* max fifo depth available */
+ u32 max_fifo = (FIFO_LVL_MASK(sdd) >> 1) + 1;
+
+ 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 +623,19 @@ 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 +645,53 @@ 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 = wait_for_timeout(sdd, ms);
+
+ 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;
}
@@ -652,6 +707,9 @@ static inline void disable_cs(struct s3c64xx_spi_driver_data *sdd,
sdd->tgl_spi = NULL;
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 +791,7 @@ 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 +840,7 @@ 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 +919,9 @@ 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 +935,10 @@ 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,
@@ -1287,19 +1339,19 @@ 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;
--
1.7.5.4
From: Girish K S <[email protected]>
The existing driver supports gpio based /cs signal.
For controller's that have one device per controller,
the slave device's /cs signal might be internally controlled
by the chip select bit of slave select register. They are not
externally asserted/deasserted using gpio pin.
This patch adds support for controllers with dedicated /cs pin.
if "cs-gpio" property doesnt exist in a spi dts node, the controller
would treat the /cs pin as dedicated.
Signed-off-by: Girish K S <[email protected]>
---
drivers/spi/spi-s3c64xx.c | 32 ++++++++++++++++++++++++--------
1 files changed, 24 insertions(+), 8 deletions(-)
diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index 665fe2b..07f9e00 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -208,6 +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)
@@ -570,14 +571,16 @@ 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);
@@ -706,7 +709,8 @@ 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);
@@ -1015,7 +1019,10 @@ 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);
@@ -1055,7 +1062,8 @@ 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) {
@@ -1064,9 +1072,11 @@ 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);
@@ -1144,8 +1154,10 @@ 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);
@@ -1322,7 +1334,11 @@ 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 = false;
if (pdev->dev.of_node) {
+ if (of_find_property(pdev->dev.of_node, "cs-gpio", NULL))
+ sdd->cs_gpio = true;
+
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",
--
1.7.5.4
From: Girish K S <[email protected]>
This patch adds support for the exynos5440 spi controller.
The integration of the spi IP in exynos5440 is different from
other SoC's. The I/O pins are no more configured via gpio, they
have dedicated pins.
Signed-off-by: Girish K S <[email protected]>
---
drivers/spi/spi-s3c64xx.c | 12 ++++++++++++
1 files changed, 12 insertions(+), 0 deletions(-)
diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index 07f9e00..b2ef717 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -1603,6 +1603,15 @@ 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",
@@ -1631,6 +1640,9 @@ 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);
--
1.7.5.4
On Mon, Apr 22, 2013 at 12:39:24PM +0530, Girish K S wrote:
> From: Girish K S <[email protected]>
>
> The existing driver supports gpio based /cs signal.
> For controller's that have one device per controller,
> the slave device's /cs signal might be internally controlled
> by the chip select bit of slave select register. They are not
> externally asserted/deasserted using gpio pin.
This doesn't build:
drivers/spi/spi-s3c64xx.c: In function 's3c64xx_get_slave_ctrldata':
drivers/spi/spi-s3c64xx.c:1023: error: 'sdd' undeclared (first use in this function)
drivers/spi/spi-s3c64xx.c:1023: error: (Each undeclared identifier is reported only once
drivers/spi/spi-s3c64xx.c:1023: error: for each function it appears in.)
On Mon, Apr 22, 2013 at 12:39:23PM +0530, Girish K S wrote:
> From: Girish K S <[email protected]>
>
> The 64xx spi driver supports partial polling mode.
> Only the last chunk of the transfer length is transferred
> or recieved in polling mode.
This appears to have a very noticable negative impact on SPI performance
on my S3C6410 based system. Not delved into it to test why but are you
sure it's not mistakenly selecting polling?
On Tue, Apr 23, 2013 at 8:45 PM, Mark Brown <[email protected]> wrote:
> On Mon, Apr 22, 2013 at 12:39:23PM +0530, Girish K S wrote:
>> From: Girish K S <[email protected]>
>>
>> The 64xx spi driver supports partial polling mode.
>> Only the last chunk of the transfer length is transferred
>> or recieved in polling mode.
>
> This appears to have a very noticable negative impact on SPI performance
> on my S3C6410 based system. Not delved into it to test why but are you
> sure it's not mistakenly selecting polling?
If forced to polling you should see this message "Unable to get SPI rx
dma resource. Switching to poll mode". same if Tx dma resource is not
available from platform data.
Anyways let me cross check again on my tested systems.
On Tue, Apr 23, 2013 at 8:12 PM, Mark Brown <[email protected]> wrote:
> On Mon, Apr 22, 2013 at 12:39:24PM +0530, Girish K S wrote:
>> From: Girish K S <[email protected]>
>>
>> The existing driver supports gpio based /cs signal.
>> For controller's that have one device per controller,
>> the slave device's /cs signal might be internally controlled
>> by the chip select bit of slave select register. They are not
>> externally asserted/deasserted using gpio pin.
>
> This doesn't build:
>
> drivers/spi/spi-s3c64xx.c: In function 's3c64xx_get_slave_ctrldata':
> drivers/spi/spi-s3c64xx.c:1023: error: 'sdd' undeclared (first use in this function)
> drivers/spi/spi-s3c64xx.c:1023: error: (Each undeclared identifier is reported only once
> drivers/spi/spi-s3c64xx.c:1023: error: for each function it appears in.)
Ohhhhhh. Sorry. forgot to commit the changes before patch generation