| Message ID | 20221005151309.7278-7-jagan@amarulasolutions.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm: bridge: Add Samsung MIPI DSIM bridge | expand |
On 10/5/22 17:13, Jagan Teki wrote: > 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. > > [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 You also add to the commit message that all of 8M Mini/Nano/Plus have P=14 , unlike Exynos. It also seems like the PLL in the DSIM and the clock PLLs in the 8M are the same design from Samsung. Reviewed-by: Marek Vasut <marex@denx.de>
diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c b/drivers/gpu/drm/bridge/samsung-dsim.c index b46346232c52..41970e794a7c 100644 --- a/drivers/gpu/drm/bridge/samsung-dsim.c +++ b/drivers/gpu/drm/bridge/samsung-dsim.c @@ -168,7 +168,7 @@ /* 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) @@ -368,6 +368,7 @@ 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, }; @@ -380,6 +381,7 @@ 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, }; @@ -390,6 +392,7 @@ 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, }; @@ -401,6 +404,7 @@ 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, }; @@ -412,6 +416,7 @@ 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, }; @@ -543,7 +548,8 @@ 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; };