DSISRC __________
                       __\_
                      |    \
        pll4_p_ck   ->|  1  |____dsi_k
        ck_dsi_phy  ->|  0  |
                      |____/

A DSI clock is missing in the clock framework. Looking at the
clk_summary, it appears that 'ck_dsi_phy' is not implemented. Since the
DSI kernel clock is based on the internal DSI pll. The common clock
driver can not directly expose this 'ck_dsi_phy' clock because it does
not contain any common registers with the DSI. Thus it needs to be done
directly within the DSI phy driver.

Signed-off-by: Raphael Gallais-Pou <raphael.gallais-...@foss.st.com>
---
 drivers/gpu/drm/stm/dw_mipi_dsi-stm.c | 246 ++++++++++++++++++++++----
 1 file changed, 215 insertions(+), 31 deletions(-)

diff --git a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c 
b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
index a0ca4d7f3b8a..1a4a88ecffe0 100644
--- a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
+++ b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
@@ -7,7 +7,9 @@
  */
 
 #include <linux/clk.h>
+#include <linux/clk-provider.h>
 #include <linux/iopoll.h>
+#include <linux/kernel.h>
 #include <linux/mod_devicetable.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
@@ -77,9 +79,12 @@ enum dsi_color {
 
 struct dw_mipi_dsi_stm {
        void __iomem *base;
+       struct device *dev;
        struct clk *pllref_clk;
        struct clk *pclk;
+       struct clk_hw txbyte_clk;
        struct dw_mipi_dsi *dsi;
+       struct dw_mipi_dsi_plat_data pdata;
        u32 hw_version;
        int lane_min_kbps;
        int lane_max_kbps;
@@ -196,29 +201,198 @@ static int dsi_pll_get_params(struct dw_mipi_dsi_stm 
*dsi,
        return 0;
 }
 
-static int dw_mipi_dsi_phy_init(void *priv_data)
+#define clk_to_dw_mipi_dsi_stm(clk) \
+       container_of(clk, struct dw_mipi_dsi_stm, txbyte_clk)
+
+static void dw_mipi_dsi_clk_disable(struct clk_hw *clk)
 {
-       struct dw_mipi_dsi_stm *dsi = priv_data;
+       struct dw_mipi_dsi_stm *dsi = clk_to_dw_mipi_dsi_stm(clk);
+
+       DRM_DEBUG_DRIVER("\n");
+
+       /* Disable the DSI PLL */
+       dsi_clear(dsi, DSI_WRPCR, WRPCR_PLLEN);
+
+       /* Disable the regulator */
+       dsi_clear(dsi, DSI_WRPCR, WRPCR_REGEN | WRPCR_BGREN);
+}
+
+static int dw_mipi_dsi_clk_enable(struct clk_hw *clk)
+{
+       struct dw_mipi_dsi_stm *dsi = clk_to_dw_mipi_dsi_stm(clk);
        u32 val;
        int ret;
 
+       DRM_DEBUG_DRIVER("\n");
+
        /* Enable the regulator */
        dsi_set(dsi, DSI_WRPCR, WRPCR_REGEN | WRPCR_BGREN);
-       ret = readl_poll_timeout(dsi->base + DSI_WISR, val, val & WISR_RRS,
-                                SLEEP_US, TIMEOUT_US);
+       ret = readl_poll_timeout_atomic(dsi->base + DSI_WISR, val, val & 
WISR_RRS,
+                                       SLEEP_US, TIMEOUT_US);
        if (ret)
                DRM_DEBUG_DRIVER("!TIMEOUT! waiting REGU, let's continue\n");
 
        /* Enable the DSI PLL & wait for its lock */
        dsi_set(dsi, DSI_WRPCR, WRPCR_PLLEN);
-       ret = readl_poll_timeout(dsi->base + DSI_WISR, val, val & WISR_PLLLS,
-                                SLEEP_US, TIMEOUT_US);
+       ret = readl_poll_timeout_atomic(dsi->base + DSI_WISR, val, val & 
WISR_PLLLS,
+                                       SLEEP_US, TIMEOUT_US);
        if (ret)
                DRM_DEBUG_DRIVER("!TIMEOUT! waiting PLL, let's continue\n");
 
        return 0;
 }
 
+static int dw_mipi_dsi_clk_is_enabled(struct clk_hw *hw)
+{
+       struct dw_mipi_dsi_stm *dsi = clk_to_dw_mipi_dsi_stm(hw);
+
+       return dsi_read(dsi, DSI_WRPCR) & WRPCR_PLLEN;
+}
+
+static unsigned long dw_mipi_dsi_clk_recalc_rate(struct clk_hw *hw,
+                                                unsigned long parent_rate)
+{
+       struct dw_mipi_dsi_stm *dsi = clk_to_dw_mipi_dsi_stm(hw);
+       unsigned int idf, ndiv, odf, pll_in_khz, pll_out_khz;
+       u32 val;
+
+       DRM_DEBUG_DRIVER("\n");
+
+       pll_in_khz = (unsigned int)(parent_rate / 1000);
+
+       val = dsi_read(dsi, DSI_WRPCR);
+
+       idf = (val & WRPCR_IDF) >> 11;
+       if (!idf)
+               idf = 1;
+       ndiv = (val & WRPCR_NDIV) >> 2;
+       odf = int_pow(2, (val & WRPCR_ODF) >> 16);
+
+       /* Get the adjusted pll out value */
+       pll_out_khz = dsi_pll_get_clkout_khz(pll_in_khz, idf, ndiv, odf);
+
+       return (unsigned long)pll_out_khz * 1000;
+}
+
+static long dw_mipi_dsi_clk_round_rate(struct clk_hw *hw, unsigned long rate,
+                                      unsigned long *parent_rate)
+{
+       struct dw_mipi_dsi_stm *dsi = clk_to_dw_mipi_dsi_stm(hw);
+       unsigned int idf, ndiv, odf, pll_in_khz, pll_out_khz;
+       int ret;
+
+       DRM_DEBUG_DRIVER("\n");
+
+       pll_in_khz = (unsigned int)(*parent_rate / 1000);
+
+       /* Compute best pll parameters */
+       idf = 0;
+       ndiv = 0;
+       odf = 0;
+
+       ret = dsi_pll_get_params(dsi, pll_in_khz, rate / 1000,
+                                &idf, &ndiv, &odf);
+       if (ret)
+               DRM_WARN("Warning dsi_pll_get_params(): bad params\n");
+
+       /* Get the adjusted pll out value */
+       pll_out_khz = dsi_pll_get_clkout_khz(pll_in_khz, idf, ndiv, odf);
+
+       return pll_out_khz * 1000;
+}
+
+static int dw_mipi_dsi_clk_set_rate(struct clk_hw *hw, unsigned long rate,
+                                   unsigned long parent_rate)
+{
+       struct dw_mipi_dsi_stm *dsi = clk_to_dw_mipi_dsi_stm(hw);
+       unsigned int idf, ndiv, odf, pll_in_khz, pll_out_khz;
+       int ret;
+       u32 val;
+
+       DRM_DEBUG_DRIVER("\n");
+
+       pll_in_khz = (unsigned int)(parent_rate / 1000);
+
+       /* Compute best pll parameters */
+       idf = 0;
+       ndiv = 0;
+       odf = 0;
+
+       ret = dsi_pll_get_params(dsi, pll_in_khz, rate / 1000, &idf, &ndiv, 
&odf);
+       if (ret)
+               DRM_WARN("Warning dsi_pll_get_params(): bad params\n");
+
+       /* Get the adjusted pll out value */
+       pll_out_khz = dsi_pll_get_clkout_khz(pll_in_khz, idf, ndiv, odf);
+
+       /* Set the PLL division factors */
+       dsi_update_bits(dsi, DSI_WRPCR, WRPCR_NDIV | WRPCR_IDF | WRPCR_ODF,
+                       (ndiv << 2) | (idf << 11) | ((ffs(odf) - 1) << 16));
+
+       /* Compute uix4 & set the bit period in high-speed mode */
+       val = 4000000 / pll_out_khz;
+       dsi_update_bits(dsi, DSI_WPCR0, WPCR0_UIX4, val);
+
+       return 0;
+}
+
+static void dw_mipi_dsi_clk_unregister(void *data)
+{
+       struct dw_mipi_dsi_stm *dsi = data;
+
+       DRM_DEBUG_DRIVER("\n");
+
+       of_clk_del_provider(dsi->dev->of_node);
+       clk_hw_unregister(&dsi->txbyte_clk);
+}
+
+static const struct clk_ops dw_mipi_dsi_stm_clk_ops = {
+       .enable = dw_mipi_dsi_clk_enable,
+       .disable = dw_mipi_dsi_clk_disable,
+       .is_enabled = dw_mipi_dsi_clk_is_enabled,
+       .recalc_rate = dw_mipi_dsi_clk_recalc_rate,
+       .round_rate = dw_mipi_dsi_clk_round_rate,
+       .set_rate = dw_mipi_dsi_clk_set_rate,
+};
+
+static struct clk_init_data cdata_init = {
+       .name = "ck_dsi_phy",
+       .ops = &dw_mipi_dsi_stm_clk_ops,
+       .parent_names = (const char * []) {"ck_hse"},
+       .num_parents = 1,
+};
+
+static int dw_mipi_dsi_clk_register(struct dw_mipi_dsi_stm *dsi,
+                                   struct device *dev)
+{
+       struct device_node *node = dev->of_node;
+       int ret;
+
+       DRM_DEBUG_DRIVER("Registering clk\n");
+
+       dsi->txbyte_clk.init = &cdata_init;
+
+       ret = clk_hw_register(dev, &dsi->txbyte_clk);
+       if (ret)
+               return ret;
+
+       ret = of_clk_add_hw_provider(node, of_clk_hw_simple_get,
+                                    &dsi->txbyte_clk);
+       if (ret)
+               clk_hw_unregister(&dsi->txbyte_clk);
+
+       return ret;
+}
+
+static int dw_mipi_dsi_phy_init(void *priv_data)
+{
+       struct dw_mipi_dsi_stm *dsi = priv_data;
+       int ret;
+
+       ret = clk_prepare_enable(dsi->txbyte_clk.clk);
+       return ret;
+}
+
 static void dw_mipi_dsi_phy_power_on(void *priv_data)
 {
        struct dw_mipi_dsi_stm *dsi = priv_data;
@@ -235,6 +409,8 @@ static void dw_mipi_dsi_phy_power_off(void *priv_data)
 
        DRM_DEBUG_DRIVER("\n");
 
+       clk_disable_unprepare(dsi->txbyte_clk.clk);
+
        /* Disable the DSI wrapper */
        dsi_clear(dsi, DSI_WCR, WCR_DSIEN);
 }
@@ -245,9 +421,8 @@ dw_mipi_dsi_get_lane_mbps(void *priv_data, const struct 
drm_display_mode *mode,
                          unsigned int *lane_mbps)
 {
        struct dw_mipi_dsi_stm *dsi = priv_data;
-       unsigned int idf, ndiv, odf, pll_in_khz, pll_out_khz;
+       unsigned int pll_in_khz, pll_out_khz;
        int ret, bpp;
-       u32 val;
 
        pll_in_khz = (unsigned int)(clk_get_rate(dsi->pllref_clk) / 1000);
 
@@ -268,25 +443,10 @@ dw_mipi_dsi_get_lane_mbps(void *priv_data, const struct 
drm_display_mode *mode,
                DRM_WARN("Warning min phy mbps is used\n");
        }
 
-       /* Compute best pll parameters */
-       idf = 0;
-       ndiv = 0;
-       odf = 0;
-       ret = dsi_pll_get_params(dsi, pll_in_khz, pll_out_khz,
-                                &idf, &ndiv, &odf);
+       ret = clk_set_rate((dsi->txbyte_clk.clk), pll_out_khz * 1000);
        if (ret)
-               DRM_WARN("Warning dsi_pll_get_params(): bad params\n");
-
-       /* Get the adjusted pll out value */
-       pll_out_khz = dsi_pll_get_clkout_khz(pll_in_khz, idf, ndiv, odf);
-
-       /* Set the PLL division factors */
-       dsi_update_bits(dsi, DSI_WRPCR, WRPCR_NDIV | WRPCR_IDF | WRPCR_ODF,
-                       (ndiv << 2) | (idf << 11) | ((ffs(odf) - 1) << 16));
-
-       /* Compute uix4 & set the bit period in high-speed mode */
-       val = 4000000 / pll_out_khz;
-       dsi_update_bits(dsi, DSI_WPCR0, WPCR0_UIX4, val);
+               DRM_DEBUG_DRIVER("ERROR Could not set rate of %d to %s 
clk->name",
+                                pll_out_khz, 
clk_hw_get_name(&dsi->txbyte_clk));
 
        /* Select video mode by resetting DSIM bit */
        dsi_clear(dsi, DSI_WCFGR, WCFGR_DSIM);
@@ -445,6 +605,7 @@ static int dw_mipi_dsi_stm_probe(struct platform_device 
*pdev)
 {
        struct device *dev = &pdev->dev;
        struct dw_mipi_dsi_stm *dsi;
+       const struct dw_mipi_dsi_plat_data *pdata = 
of_device_get_match_data(dev);
        int ret;
 
        dsi = devm_kzalloc(dev, sizeof(*dsi), GFP_KERNEL);
@@ -514,18 +675,40 @@ static int dw_mipi_dsi_stm_probe(struct platform_device 
*pdev)
                dsi->lane_max_kbps *= 2;
        }
 
-       dw_mipi_dsi_stm_plat_data.base = dsi->base;
-       dw_mipi_dsi_stm_plat_data.priv_data = dsi;
+       dsi->pdata = *pdata;
+       dsi->pdata.base = dsi->base;
+       dsi->pdata.priv_data = dsi;
+
+       dsi->pdata.max_data_lanes = 2;
+       dsi->pdata.phy_ops = &dw_mipi_dsi_stm_phy_ops;
 
        platform_set_drvdata(pdev, dsi);
 
-       dsi->dsi = dw_mipi_dsi_probe(pdev, &dw_mipi_dsi_stm_plat_data);
+       dsi->dsi = dw_mipi_dsi_probe(pdev, &dsi->pdata);
        if (IS_ERR(dsi->dsi)) {
                ret = PTR_ERR(dsi->dsi);
                dev_err_probe(dev, ret, "Failed to initialize mipi dsi host\n");
                goto err_dsi_probe;
        }
 
+       /*
+        * We need to wait for the generic bridge to probe before enabling and
+        * register the internal pixel clock.
+        */
+       ret = clk_prepare_enable(dsi->pclk);
+       if (ret) {
+               DRM_ERROR("%s: Failed to enable peripheral clk\n", __func__);
+               goto err_dsi_probe;
+       }
+
+       ret = dw_mipi_dsi_clk_register(dsi, dev);
+       if (ret) {
+               DRM_ERROR("Failed to register DSI pixel clock: %d\n", ret);
+               goto err_dsi_probe;
+       }
+
+       clk_disable_unprepare(dsi->pclk);
+
        return 0;
 
 err_dsi_probe:
@@ -542,12 +725,13 @@ static void dw_mipi_dsi_stm_remove(struct platform_device 
*pdev)
 
        dw_mipi_dsi_remove(dsi->dsi);
        clk_disable_unprepare(dsi->pllref_clk);
+       dw_mipi_dsi_clk_unregister(dsi);
        regulator_disable(dsi->vdd_supply);
 }
 
 static int __maybe_unused dw_mipi_dsi_stm_suspend(struct device *dev)
 {
-       struct dw_mipi_dsi_stm *dsi = dw_mipi_dsi_stm_plat_data.priv_data;
+       struct dw_mipi_dsi_stm *dsi = dev_get_drvdata(dev);
 
        DRM_DEBUG_DRIVER("\n");
 
@@ -560,7 +744,7 @@ static int __maybe_unused dw_mipi_dsi_stm_suspend(struct 
device *dev)
 
 static int __maybe_unused dw_mipi_dsi_stm_resume(struct device *dev)
 {
-       struct dw_mipi_dsi_stm *dsi = dw_mipi_dsi_stm_plat_data.priv_data;
+       struct dw_mipi_dsi_stm *dsi = dev_get_drvdata(dev);
        int ret;
 
        DRM_DEBUG_DRIVER("\n");
-- 
2.25.1

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