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authorJassi Brar <jassi.brar@samsung.com>2010-09-29 17:31:33 +0900
committerGrant Likely <grant.likely@secretlab.ca>2010-09-29 17:31:33 +0900
commitb42a81ca0fa7b3b442a0731ffc4e7db44464b5f2 (patch)
tree3f435d56cbb27cf47ca9fb8bc354a8d3f7f9373c /drivers
parente02ddd442a532c73e547ae3735c8012e3bd719a5 (diff)
spi/s3c64xx: Consider the clk_from_cmu flag
Newer SoCs have the SPI clock scaling control in platform's clock management unit. Inorder for such SoCs to work, we need to check the flag clk_from_cmu before making any clock changes. Signed-off-by: Jassi Brar <jassi.brar@samsung.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/spi/spi_s3c64xx.c94
1 files changed, 56 insertions, 38 deletions
diff --git a/drivers/spi/spi_s3c64xx.c b/drivers/spi/spi_s3c64xx.c
index e7b893f2a21..9e0aa3c7b4d 100644
--- a/drivers/spi/spi_s3c64xx.c
+++ b/drivers/spi/spi_s3c64xx.c
@@ -399,13 +399,18 @@ static inline void disable_cs(struct s3c64xx_spi_driver_data *sdd,
static void s3c64xx_spi_config(struct s3c64xx_spi_driver_data *sdd)
{
+ struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
void __iomem *regs = sdd->regs;
u32 val;
/* Disable Clock */
- val = readl(regs + S3C64XX_SPI_CLK_CFG);
- val &= ~S3C64XX_SPI_ENCLK_ENABLE;
- writel(val, regs + S3C64XX_SPI_CLK_CFG);
+ if (sci->clk_from_cmu) {
+ clk_disable(sdd->src_clk);
+ } else {
+ val = readl(regs + S3C64XX_SPI_CLK_CFG);
+ val &= ~S3C64XX_SPI_ENCLK_ENABLE;
+ writel(val, regs + S3C64XX_SPI_CLK_CFG);
+ }
/* Set Polarity and Phase */
val = readl(regs + S3C64XX_SPI_CH_CFG);
@@ -441,17 +446,25 @@ static void s3c64xx_spi_config(struct s3c64xx_spi_driver_data *sdd)
writel(val, regs + S3C64XX_SPI_MODE_CFG);
- /* Configure Clock */
- val = readl(regs + S3C64XX_SPI_CLK_CFG);
- val &= ~S3C64XX_SPI_PSR_MASK;
- val |= ((clk_get_rate(sdd->src_clk) / sdd->cur_speed / 2 - 1)
- & S3C64XX_SPI_PSR_MASK);
- writel(val, regs + S3C64XX_SPI_CLK_CFG);
-
- /* Enable Clock */
- val = readl(regs + S3C64XX_SPI_CLK_CFG);
- val |= S3C64XX_SPI_ENCLK_ENABLE;
- writel(val, regs + S3C64XX_SPI_CLK_CFG);
+ if (sci->clk_from_cmu) {
+ /* Configure Clock */
+ /* There is half-multiplier before the SPI */
+ clk_set_rate(sdd->src_clk, sdd->cur_speed * 2);
+ /* Enable Clock */
+ clk_enable(sdd->src_clk);
+ } else {
+ /* Configure Clock */
+ val = readl(regs + S3C64XX_SPI_CLK_CFG);
+ val &= ~S3C64XX_SPI_PSR_MASK;
+ val |= ((clk_get_rate(sdd->src_clk) / sdd->cur_speed / 2 - 1)
+ & S3C64XX_SPI_PSR_MASK);
+ writel(val, regs + S3C64XX_SPI_CLK_CFG);
+
+ /* Enable Clock */
+ val = readl(regs + S3C64XX_SPI_CLK_CFG);
+ val |= S3C64XX_SPI_ENCLK_ENABLE;
+ writel(val, regs + S3C64XX_SPI_CLK_CFG);
+ }
}
static void s3c64xx_spi_dma_rxcb(struct s3c2410_dma_chan *chan, void *buf_id,
@@ -806,7 +819,6 @@ static int s3c64xx_spi_setup(struct spi_device *spi)
struct s3c64xx_spi_driver_data *sdd;
struct s3c64xx_spi_info *sci;
struct spi_message *msg;
- u32 psr, speed;
unsigned long flags;
int err = 0;
@@ -849,32 +861,37 @@ static int s3c64xx_spi_setup(struct spi_device *spi)
}
/* Check if we can provide the requested rate */
- speed = clk_get_rate(sdd->src_clk) / 2 / (0 + 1); /* Max possible */
-
- if (spi->max_speed_hz > speed)
- spi->max_speed_hz = speed;
-
- psr = clk_get_rate(sdd->src_clk) / 2 / spi->max_speed_hz - 1;
- psr &= S3C64XX_SPI_PSR_MASK;
- if (psr == S3C64XX_SPI_PSR_MASK)
- psr--;
+ if (!sci->clk_from_cmu) {
+ u32 psr, speed;
+
+ /* Max possible */
+ speed = clk_get_rate(sdd->src_clk) / 2 / (0 + 1);
+
+ if (spi->max_speed_hz > speed)
+ spi->max_speed_hz = speed;
+
+ psr = clk_get_rate(sdd->src_clk) / 2 / spi->max_speed_hz - 1;
+ psr &= S3C64XX_SPI_PSR_MASK;
+ if (psr == S3C64XX_SPI_PSR_MASK)
+ psr--;
+
+ speed = clk_get_rate(sdd->src_clk) / 2 / (psr + 1);
+ if (spi->max_speed_hz < speed) {
+ if (psr+1 < S3C64XX_SPI_PSR_MASK) {
+ psr++;
+ } else {
+ err = -EINVAL;
+ goto setup_exit;
+ }
+ }
- speed = clk_get_rate(sdd->src_clk) / 2 / (psr + 1);
- if (spi->max_speed_hz < speed) {
- if (psr+1 < S3C64XX_SPI_PSR_MASK) {
- psr++;
- } else {
+ speed = clk_get_rate(sdd->src_clk) / 2 / (psr + 1);
+ if (spi->max_speed_hz >= speed)
+ spi->max_speed_hz = speed;
+ else
err = -EINVAL;
- goto setup_exit;
- }
}
- speed = clk_get_rate(sdd->src_clk) / 2 / (psr + 1);
- if (spi->max_speed_hz >= speed)
- spi->max_speed_hz = speed;
- else
- err = -EINVAL;
-
setup_exit:
/* setup() returns with device de-selected */
@@ -896,7 +913,8 @@ static void s3c64xx_spi_hwinit(struct s3c64xx_spi_driver_data *sdd, int channel)
/* Disable Interrupts - we use Polling if not DMA mode */
writel(0, regs + S3C64XX_SPI_INT_EN);
- writel(sci->src_clk_nr << S3C64XX_SPI_CLKSEL_SRCSHFT,
+ if (!sci->clk_from_cmu)
+ writel(sci->src_clk_nr << S3C64XX_SPI_CLKSEL_SRCSHFT,
regs + S3C64XX_SPI_CLK_CFG);
writel(0, regs + S3C64XX_SPI_MODE_CFG);
writel(0, regs + S3C64XX_SPI_PACKET_CNT);