drm/stm: dsi: add pm runtime ops

Update control of clocks and supply thanks to the PM runtime
mechanism to avoid kernel crash during a system suspend.

Signed-off-by: Yannick Fertre <yannick.fertre@foss.st.com>
Signed-off-by: Raphael Gallais-Pou <raphael.gallais-pou@foss.st.com>
Acked-by: Yannick Fertre <yannick.fertre@foss.st.com>
Tested-by: Yannick Fertre <yannick.fertre@foss.st.com>
Signed-off-by: Philippe Cornu <philippe.cornu@foss.st.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240129104106.43141-3-raphael.gallais-pou@foss.st.com

diff --git a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
index b1aee43d51e9e9fe58094d4279ccaa5a26aefc88..82fff9e84345c175a4cabfc7429901e5db6bdcc0 100644 (file)
--- a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
+++ b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
@@ -11,6 +11,7 @@
 #include <linux/mod_devicetable.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/regulator/consumer.h>
 
 #include <video/mipi_display.h>
@@ -77,6 +78,7 @@ enum dsi_color {
 struct dw_mipi_dsi_stm {
        void __iomem *base;
        struct clk *pllref_clk;
+       struct clk *pclk;
        struct dw_mipi_dsi *dsi;
        u32 hw_version;
        int lane_min_kbps;
@@ -443,7 +445,6 @@ static int dw_mipi_dsi_stm_probe(struct platform_device *pdev)
 {
        struct device *dev = &pdev->dev;
        struct dw_mipi_dsi_stm *dsi;
-       struct clk *pclk;
        int ret;
 
        dsi = devm_kzalloc(dev, sizeof(*dsi), GFP_KERNEL);
@@ -483,21 +484,21 @@ static int dw_mipi_dsi_stm_probe(struct platform_device *pdev)
                goto err_clk_get;
        }
 
-       pclk = devm_clk_get(dev, "pclk");
-       if (IS_ERR(pclk)) {
-               ret = PTR_ERR(pclk);
+       dsi->pclk = devm_clk_get(dev, "pclk");
+       if (IS_ERR(dsi->pclk)) {
+               ret = PTR_ERR(dsi->pclk);
                DRM_ERROR("Unable to get peripheral clock: %d\n", ret);
                goto err_dsi_probe;
        }
 
-       ret = clk_prepare_enable(pclk);
+       ret = clk_prepare_enable(dsi->pclk);
        if (ret) {
                DRM_ERROR("%s: Failed to enable peripheral clk\n", __func__);
                goto err_dsi_probe;
        }
 
        dsi->hw_version = dsi_read(dsi, DSI_VERSION) & VERSION;
-       clk_disable_unprepare(pclk);
+       clk_disable_unprepare(dsi->pclk);
 
        if (dsi->hw_version != HWVER_130 && dsi->hw_version != HWVER_131) {
                ret = -ENODEV;
@@ -551,6 +552,7 @@ static int dw_mipi_dsi_stm_suspend(struct device *dev)
        DRM_DEBUG_DRIVER("\n");
 
        clk_disable_unprepare(dsi->pllref_clk);
+       clk_disable_unprepare(dsi->pclk);
        regulator_disable(dsi->vdd_supply);
 
        return 0;
@@ -569,8 +571,16 @@ static int dw_mipi_dsi_stm_resume(struct device *dev)
                return ret;
        }
 
+       ret = clk_prepare_enable(dsi->pclk);
+       if (ret) {
+               regulator_disable(dsi->vdd_supply);
+               DRM_ERROR("Failed to enable pclk: %d\n", ret);
+               return ret;
+       }
+
        ret = clk_prepare_enable(dsi->pllref_clk);
        if (ret) {
+               clk_disable_unprepare(dsi->pclk);
                regulator_disable(dsi->vdd_supply);
                DRM_ERROR("Failed to enable pllref_clk: %d\n", ret);
                return ret;
@@ -582,6 +592,8 @@ static int dw_mipi_dsi_stm_resume(struct device *dev)
 static const struct dev_pm_ops dw_mipi_dsi_stm_pm_ops = {
        SYSTEM_SLEEP_PM_OPS(dw_mipi_dsi_stm_suspend,
                            dw_mipi_dsi_stm_resume)
+       RUNTIME_PM_OPS(dw_mipi_dsi_stm_suspend,
+                      dw_mipi_dsi_stm_resume, NULL)
 };
 
 static struct platform_driver dw_mipi_dsi_stm_driver = {