diff options
Diffstat (limited to 'drivers/spi/spi-sh-msiof.c')
| -rw-r--r-- | drivers/spi/spi-sh-msiof.c | 72 |
1 files changed, 39 insertions, 33 deletions
diff --git a/drivers/spi/spi-sh-msiof.c b/drivers/spi/spi-sh-msiof.c index ae086aab57d5..0e74cbf9929d 100644 --- a/drivers/spi/spi-sh-msiof.c +++ b/drivers/spi/spi-sh-msiof.c @@ -39,7 +39,7 @@ struct sh_msiof_chipdata { u16 tx_fifo_size; u16 rx_fifo_size; u16 master_flags; - u16 min_div; + u16 min_div_pow; }; struct sh_msiof_spi_priv { @@ -51,7 +51,7 @@ struct sh_msiof_spi_priv { struct completion done; unsigned int tx_fifo_size; unsigned int rx_fifo_size; - unsigned int min_div; + unsigned int min_div_pow; void *tx_dma_page; void *rx_dma_page; dma_addr_t tx_dma_addr; @@ -249,42 +249,46 @@ static irqreturn_t sh_msiof_spi_irq(int irq, void *data) return IRQ_HANDLED; } -static struct { - unsigned short div; - unsigned short brdv; -} const sh_msiof_spi_div_table[] = { - { 1, SCR_BRDV_DIV_1 }, - { 2, SCR_BRDV_DIV_2 }, - { 4, SCR_BRDV_DIV_4 }, - { 8, SCR_BRDV_DIV_8 }, - { 16, SCR_BRDV_DIV_16 }, - { 32, SCR_BRDV_DIV_32 }, +static const u32 sh_msiof_spi_div_array[] = { + SCR_BRDV_DIV_1, SCR_BRDV_DIV_2, SCR_BRDV_DIV_4, + SCR_BRDV_DIV_8, SCR_BRDV_DIV_16, SCR_BRDV_DIV_32, }; static void sh_msiof_spi_set_clk_regs(struct sh_msiof_spi_priv *p, unsigned long parent_rate, u32 spi_hz) { - unsigned long div = 1024; + unsigned long div; u32 brps, scr; - size_t k; + unsigned int div_pow = p->min_div_pow; - if (!WARN_ON(!spi_hz || !parent_rate)) - div = DIV_ROUND_UP(parent_rate, spi_hz); - - div = max_t(unsigned long, div, p->min_div); + if (!spi_hz || !parent_rate) { + WARN(1, "Invalid clock rate parameters %lu and %u\n", + parent_rate, spi_hz); + return; + } - for (k = 0; k < ARRAY_SIZE(sh_msiof_spi_div_table); k++) { - brps = DIV_ROUND_UP(div, sh_msiof_spi_div_table[k].div); + div = DIV_ROUND_UP(parent_rate, spi_hz); + if (div <= 1024) { /* SCR_BRDV_DIV_1 is valid only if BRPS is x 1/1 or x 1/2 */ - if (sh_msiof_spi_div_table[k].div == 1 && brps > 2) - continue; - if (brps <= 32) /* max of brdv is 32 */ - break; - } + if (!div_pow && div <= 32 && div > 2) + div_pow = 1; + + if (div_pow) + brps = (div + 1) >> div_pow; + else + brps = div; - k = min_t(int, k, ARRAY_SIZE(sh_msiof_spi_div_table) - 1); + for (; brps > 32; div_pow++) + brps = (brps + 1) >> 1; + } else { + /* Set transfer rate composite divisor to 2^5 * 32 = 1024 */ + dev_err(&p->pdev->dev, + "Requested SPI transfer rate %d is too low\n", spi_hz); + div_pow = 5; + brps = 32; + } - scr = sh_msiof_spi_div_table[k].brdv | SCR_BRPS(brps); + scr = sh_msiof_spi_div_array[div_pow] | SCR_BRPS(brps); sh_msiof_write(p, TSCR, scr); if (!(p->master->flags & SPI_MASTER_MUST_TX)) sh_msiof_write(p, RSCR, scr); @@ -563,14 +567,16 @@ static int sh_msiof_spi_setup(struct spi_device *spi) /* Configure native chip select mode/polarity early */ clr = MDR1_SYNCMD_MASK; - set = MDR1_TRMD | TMDR1_PCON | MDR1_SYNCMD_SPI; + set = MDR1_SYNCMD_SPI; if (spi->mode & SPI_CS_HIGH) clr |= BIT(MDR1_SYNCAC_SHIFT); else set |= BIT(MDR1_SYNCAC_SHIFT); pm_runtime_get_sync(&p->pdev->dev); tmp = sh_msiof_read(p, TMDR1) & ~clr; - sh_msiof_write(p, TMDR1, tmp | set); + sh_msiof_write(p, TMDR1, tmp | set | MDR1_TRMD | TMDR1_PCON); + tmp = sh_msiof_read(p, RMDR1) & ~clr; + sh_msiof_write(p, RMDR1, tmp | set); pm_runtime_put(&p->pdev->dev); p->native_cs_high = spi->mode & SPI_CS_HIGH; p->native_cs_inited = true; @@ -1040,21 +1046,21 @@ static const struct sh_msiof_chipdata sh_data = { .tx_fifo_size = 64, .rx_fifo_size = 64, .master_flags = 0, - .min_div = 1, + .min_div_pow = 0, }; static const struct sh_msiof_chipdata rcar_gen2_data = { .tx_fifo_size = 64, .rx_fifo_size = 64, .master_flags = SPI_MASTER_MUST_TX, - .min_div = 1, + .min_div_pow = 0, }; static const struct sh_msiof_chipdata rcar_gen3_data = { .tx_fifo_size = 64, .rx_fifo_size = 64, .master_flags = SPI_MASTER_MUST_TX, - .min_div = 2, + .min_div_pow = 1, }; static const struct of_device_id sh_msiof_match[] = { @@ -1318,7 +1324,7 @@ static int sh_msiof_spi_probe(struct platform_device *pdev) platform_set_drvdata(pdev, p); p->master = master; p->info = info; - p->min_div = chipdata->min_div; + p->min_div_pow = chipdata->min_div_pow; init_completion(&p->done); |