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| author | Geert Uytterhoeven <geert+renesas@glider.be> | 2017-07-12 12:26:01 +0200 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2017-07-17 12:09:59 +0100 |
| commit | 61a8dec502b873879fa240ec7614601523b46a43 (patch) | |
| tree | 74b5d8eddd0b48ac4b101fe91224986ed2360764 /drivers/spi/spi-sh-msiof.c | |
| parent | 3d108f1e2d4c21026750cd4107e03b3e7a3e98a0 (diff) | |
| download | linux-61a8dec502b873879fa240ec7614601523b46a43.tar.gz linux-61a8dec502b873879fa240ec7614601523b46a43.tar.bz2 linux-61a8dec502b873879fa240ec7614601523b46a43.zip | |
spi: sh-msiof: Limit minimum divider on R-Car Gen3
On R-Car Gen3 SoCs (excluding R-Car H3 ES1.x, which cannot be used for
SPI due to a hardware erratum), BRPS x BRDV = 1/1 is an invalid divider
setting.
Implement this limitation using an SoC/family-specific minimum divider.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi/spi-sh-msiof.c')
| -rw-r--r-- | drivers/spi/spi-sh-msiof.c | 32 |
1 files changed, 23 insertions, 9 deletions
diff --git a/drivers/spi/spi-sh-msiof.c b/drivers/spi/spi-sh-msiof.c index c304c7167866..0eb1e9583485 100644 --- a/drivers/spi/spi-sh-msiof.c +++ b/drivers/spi/spi-sh-msiof.c @@ -38,6 +38,7 @@ struct sh_msiof_chipdata { u16 tx_fifo_size; u16 rx_fifo_size; u16 master_flags; + u16 min_div; }; struct sh_msiof_spi_priv { @@ -49,6 +50,7 @@ struct sh_msiof_spi_priv { struct completion done; unsigned int tx_fifo_size; unsigned int rx_fifo_size; + unsigned int min_div; void *tx_dma_page; void *rx_dma_page; dma_addr_t tx_dma_addr; @@ -261,6 +263,8 @@ static void sh_msiof_spi_set_clk_regs(struct sh_msiof_spi_priv *p, if (!WARN_ON(!spi_hz || !parent_rate)) div = DIV_ROUND_UP(parent_rate, spi_hz); + div = max_t(unsigned long, div, p->min_div); + for (k = 0; k < ARRAY_SIZE(sh_msiof_spi_div_table); k++) { brps = DIV_ROUND_UP(div, sh_msiof_spi_div_table[k].div); /* SCR_BRDV_DIV_1 is valid only if BRPS is x 1/1 or x 1/2 */ @@ -998,24 +1002,33 @@ static const struct sh_msiof_chipdata sh_data = { .tx_fifo_size = 64, .rx_fifo_size = 64, .master_flags = 0, + .min_div = 1, +}; + +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, }; -static const struct sh_msiof_chipdata r8a779x_data = { +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, }; static const struct of_device_id sh_msiof_match[] = { { .compatible = "renesas,sh-mobile-msiof", .data = &sh_data }, - { .compatible = "renesas,msiof-r8a7790", .data = &r8a779x_data }, - { .compatible = "renesas,msiof-r8a7791", .data = &r8a779x_data }, - { .compatible = "renesas,msiof-r8a7792", .data = &r8a779x_data }, - { .compatible = "renesas,msiof-r8a7793", .data = &r8a779x_data }, - { .compatible = "renesas,msiof-r8a7794", .data = &r8a779x_data }, - { .compatible = "renesas,rcar-gen2-msiof", .data = &r8a779x_data }, - { .compatible = "renesas,msiof-r8a7796", .data = &r8a779x_data }, - { .compatible = "renesas,rcar-gen3-msiof", .data = &r8a779x_data }, + { .compatible = "renesas,msiof-r8a7790", .data = &rcar_gen2_data }, + { .compatible = "renesas,msiof-r8a7791", .data = &rcar_gen2_data }, + { .compatible = "renesas,msiof-r8a7792", .data = &rcar_gen2_data }, + { .compatible = "renesas,msiof-r8a7793", .data = &rcar_gen2_data }, + { .compatible = "renesas,msiof-r8a7794", .data = &rcar_gen2_data }, + { .compatible = "renesas,rcar-gen2-msiof", .data = &rcar_gen2_data }, + { .compatible = "renesas,msiof-r8a7796", .data = &rcar_gen3_data }, + { .compatible = "renesas,rcar-gen3-msiof", .data = &rcar_gen3_data }, { .compatible = "renesas,sh-msiof", .data = &sh_data }, /* Deprecated */ {}, }; @@ -1230,6 +1243,7 @@ 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; init_completion(&p->done); |