drm/msm/dsi: support CPHY mode for 7nm pll/phy

Add the required changes to support 7nm pll/phy in CPHY mode.

This adds a "qcom,dsi-phy-cphy-mode" property for the PHY node to enable
the CPHY mode.

Signed-off-by: Jonathan Marek <[email protected]>
Reviewed-by: Dmitry Baryshkov <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Dmitry Baryshkov <[email protected]>
Signed-off-by: Rob Clark <[email protected]>

drivers/gpu/drm/msm/dsi/dsi_host.c

@@ -27,6 +27,7 @@
 #include "dsi_cfg.h"
 #include "msm_kms.h"
 #include "msm_gem.h"
+#include "phy/dsi_phy.h"
 
 #define DSI_RESET_TOGGLE_DELAY_MS 20
 
@@ -167,6 +168,9 @@ struct msm_dsi_host {
 	int dlane_swap;
 	int num_data_lanes;
 
+	/* from phy DT */
+	bool cphy_mode;
+
 	u32 dma_cmd_ctrl_restore;
 
 	bool registered;
@@ -510,6 +514,7 @@ int msm_dsi_runtime_resume(struct device *dev)
 
 int dsi_link_clk_set_rate_6g(struct msm_dsi_host *msm_host)
 {
+	u32 byte_intf_rate;
 	int ret;
 
 	DBG("Set clk rates: pclk=%d, byteclk=%d",
@@ -529,8 +534,13 @@ int dsi_link_clk_set_rate_6g(struct msm_dsi_host *msm_host)
 	}
 
 	if (msm_host->byte_intf_clk) {
-		ret = clk_set_rate(msm_host->byte_intf_clk,
-				   msm_host->byte_clk_rate / 2);
+		/* For CPHY, byte_intf_clk is same as byte_clk */
+		if (msm_host->cphy_mode)
+			byte_intf_rate = msm_host->byte_clk_rate;
+		else
+			byte_intf_rate = msm_host->byte_clk_rate / 2;
+
+		ret = clk_set_rate(msm_host->byte_intf_clk, byte_intf_rate);
 		if (ret) {
 			pr_err("%s: Failed to set rate byte intf clk, %d\n",
 			       __func__, ret);
@@ -710,7 +720,11 @@ static void dsi_calc_pclk(struct msm_dsi_host *msm_host, bool is_dual_dsi)
 		lanes = 1;
 	}
 
-	do_div(pclk_bpp, (8 * lanes));
+	/* CPHY "byte_clk" is in units of 16 bits */
+	if (msm_host->cphy_mode)
+		do_div(pclk_bpp, (16 * lanes));
+	else
+		do_div(pclk_bpp, (8 * lanes));
 
 	msm_host->pixel_clk_rate = pclk_rate;
 	msm_host->byte_clk_rate = pclk_bpp;
@@ -936,6 +950,9 @@ static void dsi_ctrl_config(struct msm_dsi_host *msm_host, bool enable,
 	data |= DSI_CTRL_ENABLE;
 
 	dsi_write(msm_host, REG_DSI_CTRL, data);
+
+	if (msm_host->cphy_mode)
+		dsi_write(msm_host, REG_DSI_CPHY_MODE_CTRL, BIT(0));
 }
 
 static void dsi_timing_setup(struct msm_dsi_host *msm_host, bool is_dual_dsi)
@@ -2226,6 +2243,8 @@ int msm_dsi_host_set_src_pll(struct mipi_dsi_host *host,
 	struct clk *byte_clk_provider, *pixel_clk_provider;
 	int ret;
 
+	msm_host->cphy_mode = src_phy->cphy_mode;
+
 	ret = msm_dsi_phy_get_clk_provider(src_phy,
 				&byte_clk_provider, &pixel_clk_provider);
 	if (ret) {
@@ -2297,7 +2316,14 @@ void msm_dsi_host_get_phy_clk_req(struct mipi_dsi_host *host,
 		return;
 	}
 
-	clk_req->bitclk_rate = msm_host->byte_clk_rate * 8;
+	/* CPHY transmits 16 bits over 7 clock cycles
+	 * "byte_clk" is in units of 16-bits (see dsi_calc_pclk),
+	 * so multiply by 7 to get the "bitclk rate"
+	 */
+	if (msm_host->cphy_mode)
+		clk_req->bitclk_rate = msm_host->byte_clk_rate * 7;
+	else
+		clk_req->bitclk_rate = msm_host->byte_clk_rate * 8;
 	clk_req->escclk_rate = msm_host->esc_clk_rate;
 }
 

drivers/gpu/drm/msm/dsi/phy/dsi_phy.c

@@ -5,6 +5,7 @@
 
 #include <linux/clk-provider.h>
 #include <linux/platform_device.h>
+#include <dt-bindings/phy/phy.h>
 
 #include "dsi_phy.h"
 
@@ -461,6 +462,51 @@ int msm_dsi_dphy_timing_calc_v4(struct msm_dsi_dphy_timing *timing,
 	return 0;
 }
 
+int msm_dsi_cphy_timing_calc_v4(struct msm_dsi_dphy_timing *timing,
+	struct msm_dsi_phy_clk_request *clk_req)
+{
+	const unsigned long bit_rate = clk_req->bitclk_rate;
+	const unsigned long esc_rate = clk_req->escclk_rate;
+	s32 ui, ui_x7;
+	s32 tmax, tmin;
+	s32 coeff = 1000; /* Precision, should avoid overflow */
+	s32 temp;
+
+	if (!bit_rate || !esc_rate)
+		return -EINVAL;
+
+	ui = mult_frac(NSEC_PER_MSEC, coeff, bit_rate / 1000);
+	ui_x7 = ui * 7;
+
+	temp = S_DIV_ROUND_UP(38 * coeff, ui_x7);
+	tmin = max_t(s32, temp, 0);
+	temp = (95 * coeff) / ui_x7;
+	tmax = max_t(s32, temp, 0);
+	timing->clk_prepare = linear_inter(tmax, tmin, 50, 0, false);
+
+	tmin = DIV_ROUND_UP(50 * coeff, ui_x7);
+	tmax = 255;
+	timing->hs_rqst = linear_inter(tmax, tmin, 1, 0, false);
+
+	tmin = DIV_ROUND_UP(100 * coeff, ui_x7) - 1;
+	tmax = 255;
+	timing->hs_exit = linear_inter(tmax, tmin, 10, 0, false);
+
+	tmin = 1;
+	tmax = 32;
+	timing->shared_timings.clk_post = linear_inter(tmax, tmin, 80, 0, false);
+
+	tmin = min_t(s32, 64, S_DIV_ROUND_UP(262 * coeff, ui_x7) - 1);
+	tmax = 64;
+	timing->shared_timings.clk_pre = linear_inter(tmax, tmin, 20, 0, false);
+
+	DBG("%d, %d, %d, %d, %d",
+		timing->shared_timings.clk_pre, timing->shared_timings.clk_post,
+		timing->clk_prepare, timing->hs_exit, timing->hs_rqst);
+
+	return 0;
+}
+
 static int dsi_phy_regulator_init(struct msm_dsi_phy *phy)
 {
 	struct regulator_bulk_data *s = phy->supplies;
@@ -626,6 +672,7 @@ static int dsi_phy_driver_probe(struct platform_device *pdev)
 	struct msm_dsi_phy *phy;
 	struct device *dev = &pdev->dev;
 	const struct of_device_id *match;
+	u32 phy_type;
 	int ret;
 
 	phy = devm_kzalloc(dev, sizeof(*phy), GFP_KERNEL);
@@ -657,6 +704,8 @@ static int dsi_phy_driver_probe(struct platform_device *pdev)
 
 	phy->regulator_ldo_mode = of_property_read_bool(dev->of_node,
 				"qcom,dsi-phy-regulator-ldo-mode");
+	if (!of_property_read_u32(dev->of_node, "phy-type", &phy_type))
+		phy->cphy_mode = (phy_type == PHY_TYPE_CPHY);
 
 	phy->base = msm_ioremap_size(pdev, "dsi_phy", "DSI_PHY", &phy->base_size);
 	if (IS_ERR(phy->base)) {

drivers/gpu/drm/msm/dsi/phy/dsi_phy.h

@@ -99,6 +99,7 @@ struct msm_dsi_phy {
 
 	enum msm_dsi_phy_usecase usecase;
 	bool regulator_ldo_mode;
+	bool cphy_mode;
 
 	struct clk_hw *vco_hw;
 	bool pll_on;
@@ -119,5 +120,7 @@ int msm_dsi_dphy_timing_calc_v3(struct msm_dsi_dphy_timing *timing,
 				struct msm_dsi_phy_clk_request *clk_req);
 int msm_dsi_dphy_timing_calc_v4(struct msm_dsi_dphy_timing *timing,
 				struct msm_dsi_phy_clk_request *clk_req);
+int msm_dsi_cphy_timing_calc_v4(struct msm_dsi_dphy_timing *timing,
+				struct msm_dsi_phy_clk_request *clk_req);
 
 #endif /* __DSI_PHY_H__ */