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+rene...@glider.be>
---
drivers/spi/spi-sh-msiof.c | 32 +++++++++++++++++++++++---------
1 file changed, 23 insertions(+), 9 deletions(-)
diff --git a/drivers/spi/spi-sh-msiof.c b/drivers/spi/spi-sh-msiof.c
index c304c7167866d2db..0eb1e95834854fb6 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);
--
2.7.4
