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spi: sh-msiof: Limit minimum divider on R-Car Gen3

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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>
This commit is contained in:
Geert Uytterhoeven 2017-07-12 12:26:01 +02:00 committed by Mark Brown
parent 3d108f1e2d
commit 61a8dec502
1 changed files with 23 additions and 9 deletions
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32
drivers/spi/spi-sh-msiof.c
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@ -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 r8a779x_data = {
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 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);