Look like PLL PMS_P offset value varies between platforms that have Samsung DSIM IP. However, there is no clear evidence for it as both Exynos and i.MX 8M Mini Application Processor Reference Manual is still referring the PMS_P offset as 13. The offset 13 is not working for i.MX8M Mini SoCs but the downstream NXP sec-dsim.c driver is using offset 14 for i.MX8M Mini SoC platforms [1] [2]. PMS_P value set in sec_mipi_dsim_check_pll_out using PLLCTRL_SET_P() with offset 13 and then an additional offset of one bit added in sec_mipi_dsim_config_pll via PLLCTRL_SET_PMS(). Not sure whether it is reference manual documentation or something else but this patch trusts the downstream code and handle PLL_P offset via platform driver data so-that imx8mm driver data shall use pll_p_offset to 14. Similar to Mini the i.MX8M Nano/Plus also has P=14, unlike Exynos. [1] https://source.codeaurora.org/external/imx/linux-imx/tree/drivers/gpu/drm/bridge/sec-dsim.c?h=imx_5.4.47_2.2.0#n210 [2] https://source.codeaurora.org/external/imx/linux-imx/tree/drivers/gpu/drm/bridge/sec-dsim.c?h=imx_5.4.47_2.2.0#n211 v9: * none v8: * updated commit message for 8M Nano/Plus v7, v6: * none v5: * updated clear commit message v4, v3, v2: * none v1: * updated commit message * add downstream driver link Reviewed-by: Marek Vasut <marex@xxxxxxx> Signed-off-by: Frieder Schrempf <frieder.schrempf@xxxxxxxxxx> Signed-off-by: Jagan Teki <jagan@xxxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/bridge/samsung-dsim.c | 10 ++++++++-- include/drm/bridge/samsung-dsim.h | 1 + 2 files changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c b/drivers/gpu/drm/bridge/samsung-dsim.c index c79f7dc49e17..9203116f1efb 100644 --- a/drivers/gpu/drm/bridge/samsung-dsim.c +++ b/drivers/gpu/drm/bridge/samsung-dsim.c @@ -184,7 +184,7 @@ /* DSIM_PLLCTRL */ #define DSIM_FREQ_BAND(x) ((x) << 24) #define DSIM_PLL_EN (1 << 23) -#define DSIM_PLL_P(x) ((x) << 13) +#define DSIM_PLL_P(x, offset) ((x) << (offset)) #define DSIM_PLL_M(x) ((x) << 4) #define DSIM_PLL_S(x) ((x) << 1) @@ -384,6 +384,7 @@ static const struct samsung_dsim_driver_data exynos3_dsi_driver_data = { .max_freq = 1000, .wait_for_reset = 1, .num_bits_resol = 11, + .pll_p_offset = 13, .reg_values = reg_values, }; @@ -396,6 +397,7 @@ static const struct samsung_dsim_driver_data exynos4_dsi_driver_data = { .max_freq = 1000, .wait_for_reset = 1, .num_bits_resol = 11, + .pll_p_offset = 13, .reg_values = reg_values, }; @@ -406,6 +408,7 @@ static const struct samsung_dsim_driver_data exynos5_dsi_driver_data = { .max_freq = 1000, .wait_for_reset = 1, .num_bits_resol = 11, + .pll_p_offset = 13, .reg_values = reg_values, }; @@ -417,6 +420,7 @@ static const struct samsung_dsim_driver_data exynos5433_dsi_driver_data = { .max_freq = 1500, .wait_for_reset = 0, .num_bits_resol = 12, + .pll_p_offset = 13, .reg_values = exynos5433_reg_values, }; @@ -428,6 +432,7 @@ static const struct samsung_dsim_driver_data exynos5422_dsi_driver_data = { .max_freq = 1500, .wait_for_reset = 1, .num_bits_resol = 12, + .pll_p_offset = 13, .reg_values = exynos5422_reg_values, }; @@ -559,7 +564,8 @@ static unsigned long samsung_dsim_set_pll(struct samsung_dsim *dsi, writel(driver_data->reg_values[PLL_TIMER], dsi->reg_base + driver_data->plltmr_reg); - reg = DSIM_PLL_EN | DSIM_PLL_P(p) | DSIM_PLL_M(m) | DSIM_PLL_S(s); + reg = DSIM_PLL_EN | DSIM_PLL_P(p, driver_data->pll_p_offset) | + DSIM_PLL_M(m) | DSIM_PLL_S(s); if (driver_data->has_freqband) { static const unsigned long freq_bands[] = { diff --git a/include/drm/bridge/samsung-dsim.h b/include/drm/bridge/samsung-dsim.h index 0c5a905f3de7..df3d030daec6 100644 --- a/include/drm/bridge/samsung-dsim.h +++ b/include/drm/bridge/samsung-dsim.h @@ -53,6 +53,7 @@ struct samsung_dsim_driver_data { unsigned int max_freq; unsigned int wait_for_reset; unsigned int num_bits_resol; + unsigned int pll_p_offset; const unsigned int *reg_values; }; -- 2.25.1
