[PATCH 1/2 v2] SPI: spi-pxa2xx: Add helpers for regiseters' accessing
From: Weike Chen
Date: Mon Sep 29 2014 - 02:32:36 EST
Introduce helper functions to access the 'SSCR0' and 'SSCR1'.
Signed-off-by: Weike Chen <alvin.chen@xxxxxxxxx>
---
drivers/spi/spi-pxa2xx.c | 108 ++++++++++++++++++++++++++++++++++++----------
1 file changed, 85 insertions(+), 23 deletions(-)
diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c
index 256c0ab..e7ff9c5 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 +587,12 @@ 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 +683,7 @@ 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 +802,7 @@ 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 +839,15 @@ 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 +1025,8 @@ 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);
--
1.7.9.5
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