[PATCH 1/2 v2] SPI: spi-pxa2xx: Add helpers for regiseters' accessing
Andy Shevchenko
andriy.shevchenko at linux.intel.com
Mon Sep 29 01:52:17 PDT 2014
On Mon, 2014-09-29 at 07:22 -0700, Weike Chen wrote:
I'm okay with the current version, though I have few minor comments
below.
> Introduce helper functions to access the 'SSCR0' and 'SSCR1'.
>
Like you said in the summary there are many accessors to many registers,
not only cr1/cr0. Perhaps, you may extend your commit message.
In any case
Reviewed-by: Andy Shevchenko <andriy.shevchenko at linux.intel.com>
More comments below.
> Signed-off-by: Weike Chen <alvin.chen at intel.com>
> ---
> 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))
Just wondering if those two could fit one line.
> 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))
Ditto.
> 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))
Ditto.
> 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))
Ditto.
> 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);
--
Andy Shevchenko <andriy.shevchenko at linux.intel.com>
Intel Finland Oy
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