[PATCH 05/11] drm: bridge: samsung-dsim: Fix PLL_P (PMS_P) offset

[Jagan Teki <jagan@amarulasolutions.com>]

The i.MX 8M Mini Applications Processor Reference Manual, Rev. 3, 11/2020
with 13.7.10.1 Master PLL PMS Value setting Register mentioned PMS_P offset
range from BIT[18-13] and the upstream driver is using the same offset.

However, offset 13 is not working on i.MX8M Mini platforms but downstream
NXP driver is using 14 [1] and it is working with i.MX8M Mini SoC.

Not sure about whether it is reference manual documentation or something
else but this patch trusts the downstream code and fixes the PLL_P offset.

[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#n211

v1:
* updated commit message
* add downstream driver link

Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
---
 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 3e12b469dfa8..423d654e8ffd 100644
--- a/drivers/gpu/drm/bridge/samsung-dsim.c
+++ b/drivers/gpu/drm/bridge/samsung-dsim.c
@@ -169,7 +169,7 @@
 /* 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)
 
@@ -369,6 +369,7 @@ 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,
 	.platform_init = true,
 };
@@ -382,6 +383,7 @@ 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,
 	.platform_init = true,
 };
@@ -393,6 +395,7 @@ 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,
 	.platform_init = true,
 };
@@ -405,6 +408,7 @@ 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,
 	.platform_init = true,
 };
@@ -417,6 +421,7 @@ 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,
 	.platform_init = true,
 };
@@ -564,7 +569,8 @@ 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 eca7eacb5910..4eb48ec6543f 100644
--- a/include/drm/bridge/samsung-dsim.h
+++ b/include/drm/bridge/samsung-dsim.h
@@ -38,6 +38,7 @@ 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;
 	bool platform_init;
 };
-- 
2.25.1