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authorWeike Chen <alvin.chen@intel.com>2014-10-08 08:50:22 -0700
committerMark Brown <broonie@kernel.org>2014-11-24 19:00:01 +0000
commit4fdb2424cc4499237197a8c9d35b34d68c750475 (patch)
tree7752eaffb5df46255a2016a2f7d8af35c9d101fd /drivers/spi
parent5d01410fe4d92081f349b013a2e7a95429e4f2c9 (diff)
downloadlinux-4fdb2424cc4499237197a8c9d35b34d68c750475.tar.bz2
spi: spi-pxa2xx: Add helpers for regiseters' accessing
There are several registers for SPI, and the registers of 'SSCR0' and 'SSCR1' are accessed frequently. This path is to introduce helper functions to simplify the accessing of 'SSCR0' and 'SSCR1'. Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Weike Chen <alvin.chen@intel.com> Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi')
-rw-r--r--drivers/spi/spi-pxa2xx.c107
1 files changed, 84 insertions, 23 deletions
diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c
index 9e9e0f971e6c..d4d29c594156 100644
--- a/drivers/spi/spi-pxa2xx.c
+++ b/drivers/spi/spi-pxa2xx.c
@@ -80,6 +80,73 @@ static bool is_lpss_ssp(const struct driver_data *drv_data)
return drv_data->ssp_type == LPSS_SSP;
}
+static u32 pxa2xx_spi_get_ssrc1_change_mask(const struct driver_data *drv_data)
+{
+ switch (drv_data->ssp_type) {
+ default:
+ return SSCR1_CHANGE_MASK;
+ }
+}
+
+static u32
+pxa2xx_spi_get_rx_default_thre(const struct driver_data *drv_data)
+{
+ switch (drv_data->ssp_type) {
+ default:
+ return RX_THRESH_DFLT;
+ }
+}
+
+static bool pxa2xx_spi_txfifo_full(const struct driver_data *drv_data)
+{
+ void __iomem *reg = drv_data->ioaddr;
+ u32 mask;
+
+ switch (drv_data->ssp_type) {
+ default:
+ mask = SSSR_TFL_MASK;
+ break;
+ }
+
+ return (read_SSSR(reg) & mask) == mask;
+}
+
+static void pxa2xx_spi_clear_rx_thre(const struct driver_data *drv_data,
+ u32 *sccr1_reg)
+{
+ u32 mask;
+
+ switch (drv_data->ssp_type) {
+ default:
+ mask = SSCR1_RFT;
+ break;
+ }
+ *sccr1_reg &= ~mask;
+}
+
+static void pxa2xx_spi_set_rx_thre(const struct driver_data *drv_data,
+ u32 *sccr1_reg, u32 threshold)
+{
+ switch (drv_data->ssp_type) {
+ default:
+ *sccr1_reg |= SSCR1_RxTresh(threshold);
+ break;
+ }
+}
+
+static u32 pxa2xx_configure_sscr0(const struct driver_data *drv_data,
+ u32 clk_div, u8 bits)
+{
+ switch (drv_data->ssp_type) {
+ default:
+ return clk_div
+ | SSCR0_Motorola
+ | SSCR0_DataSize(bits > 16 ? bits - 16 : bits)
+ | SSCR0_SSE
+ | (bits > 16 ? SSCR0_EDSS : 0);
+ }
+}
+
/*
* Read and write LPSS SSP private registers. Caller must first check that
* is_lpss_ssp() returns true before these can be called.
@@ -234,7 +301,7 @@ static int null_writer(struct driver_data *drv_data)
void __iomem *reg = drv_data->ioaddr;
u8 n_bytes = drv_data->n_bytes;
- if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)
+ if (pxa2xx_spi_txfifo_full(drv_data)
|| (drv_data->tx == drv_data->tx_end))
return 0;
@@ -262,7 +329,7 @@ static int u8_writer(struct driver_data *drv_data)
{
void __iomem *reg = drv_data->ioaddr;
- if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)
+ if (pxa2xx_spi_txfifo_full(drv_data)
|| (drv_data->tx == drv_data->tx_end))
return 0;
@@ -289,7 +356,7 @@ static int u16_writer(struct driver_data *drv_data)
{
void __iomem *reg = drv_data->ioaddr;
- if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)
+ if (pxa2xx_spi_txfifo_full(drv_data)
|| (drv_data->tx == drv_data->tx_end))
return 0;
@@ -316,7 +383,7 @@ static int u32_writer(struct driver_data *drv_data)
{
void __iomem *reg = drv_data->ioaddr;
- if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)
+ if (pxa2xx_spi_txfifo_full(drv_data)
|| (drv_data->tx == drv_data->tx_end))
return 0;
@@ -508,8 +575,9 @@ static irqreturn_t interrupt_transfer(struct driver_data *drv_data)
* remaining RX bytes.
*/
if (pxa25x_ssp_comp(drv_data)) {
+ u32 rx_thre;
- sccr1_reg &= ~SSCR1_RFT;
+ pxa2xx_spi_clear_rx_thre(drv_data, &sccr1_reg);
bytes_left = drv_data->rx_end - drv_data->rx;
switch (drv_data->n_bytes) {
@@ -519,10 +587,11 @@ static irqreturn_t interrupt_transfer(struct driver_data *drv_data)
bytes_left >>= 1;
}
- if (bytes_left > RX_THRESH_DFLT)
- bytes_left = RX_THRESH_DFLT;
+ rx_thre = pxa2xx_spi_get_rx_default_thre(drv_data);
+ if (rx_thre > bytes_left)
+ rx_thre = bytes_left;
- sccr1_reg |= SSCR1_RxTresh(bytes_left);
+ pxa2xx_spi_set_rx_thre(drv_data, &sccr1_reg, rx_thre);
}
write_SSCR1(sccr1_reg, reg);
}
@@ -613,6 +682,7 @@ static void pump_transfers(unsigned long data)
u32 cr1;
u32 dma_thresh = drv_data->cur_chip->dma_threshold;
u32 dma_burst = drv_data->cur_chip->dma_burst_size;
+ u32 change_mask = pxa2xx_spi_get_ssrc1_change_mask(drv_data);
/* Get current state information */
message = drv_data->cur_msg;
@@ -731,11 +801,7 @@ static void pump_transfers(unsigned long data)
"pump_transfers: DMA burst size reduced to match bits_per_word\n");
}
- cr0 = clk_div
- | SSCR0_Motorola
- | SSCR0_DataSize(bits > 16 ? bits - 16 : bits)
- | SSCR0_SSE
- | (bits > 16 ? SSCR0_EDSS : 0);
+ cr0 = pxa2xx_configure_sscr0(drv_data, clk_div, bits);
}
message->state = RUNNING_STATE;
@@ -772,16 +838,15 @@ static void pump_transfers(unsigned long data)
}
/* see if we need to reload the config registers */
- if ((read_SSCR0(reg) != cr0)
- || (read_SSCR1(reg) & SSCR1_CHANGE_MASK) !=
- (cr1 & SSCR1_CHANGE_MASK)) {
+ if ((read_SSCR0(reg) != cr0) ||
+ (read_SSCR1(reg) & change_mask) != (cr1 & change_mask)) {
/* stop the SSP, and update the other bits */
write_SSCR0(cr0 & ~SSCR0_SSE, reg);
if (!pxa25x_ssp_comp(drv_data))
write_SSTO(chip->timeout, reg);
/* first set CR1 without interrupt and service enables */
- write_SSCR1(cr1 & SSCR1_CHANGE_MASK, reg);
+ write_SSCR1(cr1 & change_mask, reg);
/* restart the SSP */
write_SSCR0(cr0, reg);
@@ -959,12 +1024,8 @@ static int setup(struct spi_device *spi)
clk_div = ssp_get_clk_div(drv_data, spi->max_speed_hz);
chip->speed_hz = spi->max_speed_hz;
- chip->cr0 = clk_div
- | SSCR0_Motorola
- | SSCR0_DataSize(spi->bits_per_word > 16 ?
- spi->bits_per_word - 16 : spi->bits_per_word)
- | SSCR0_SSE
- | (spi->bits_per_word > 16 ? SSCR0_EDSS : 0);
+ chip->cr0 = pxa2xx_configure_sscr0(drv_data, clk_div,
+ spi->bits_per_word);
chip->cr1 &= ~(SSCR1_SPO | SSCR1_SPH);
chip->cr1 |= (((spi->mode & SPI_CPHA) != 0) ? SSCR1_SPH : 0)
| (((spi->mode & SPI_CPOL) != 0) ? SSCR1_SPO : 0);