drm/exynos: rework fimc clocks handling

The clocks handling is refactored and a "mux" clock handling is
added to account for changes in the clocks driver. After switching
to the common clock framework the sclk_fimc clock is now split
into two clocks: a gate and a mux clock. In order to retain the
exisiting functionality two additional consumer clocks are passed
to the driver from device tree: "mux" and "parent". Then the driver
sets "parent" clock as a parent clock of the "mux" clock. These two
additional clocks are optional, and should go away when there is a
standard way of setting up parent clocks on DT platforms.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

drivers/gpu/drm/exynos/exynos_drm_fimc.c

@@ -76,6 +76,27 @@ enum fimc_wb {
 	FIMC_WB_B,
 };
 
+enum {
+	FIMC_CLK_LCLK,
+	FIMC_CLK_GATE,
+	FIMC_CLK_WB_A,
+	FIMC_CLK_WB_B,
+	FIMC_CLK_MUX,
+	FIMC_CLK_PARENT,
+	FIMC_CLKS_MAX
+};
+
+static const char * const fimc_clock_names[] = {
+	[FIMC_CLK_LCLK]   = "sclk_fimc",
+	[FIMC_CLK_GATE]   = "fimc",
+	[FIMC_CLK_WB_A]   = "pxl_async0",
+	[FIMC_CLK_WB_B]   = "pxl_async1",
+	[FIMC_CLK_MUX]    = "mux",
+	[FIMC_CLK_PARENT] = "parent",
+};
+
+#define FIMC_DEFAULT_LCLK_FREQUENCY 133000000UL
+
 /*
  * A structure of scaler.
  *
@@ -134,13 +155,9 @@ struct fimc_driverdata {
  * @regs_res: register resources.
  * @regs: memory mapped io registers.
  * @lock: locking of operations.
- * @sclk_fimc_clk: fimc source clock.
- * @fimc_clk: fimc clock.
- * @wb_clk: writeback a clock.
- * @wb_b_clk: writeback b clock.
+ * @clocks: fimc clocks.
+ * @clk_frequency: LCLK clock frequency.
  * @sc: scaler infomations.
- * @odr: ordering of YUV.
- * @ver: fimc version.
  * @pol: porarity of writeback.
  * @id: fimc id.
  * @irq: irq number.
@@ -151,10 +168,8 @@ struct fimc_context {
 	struct resource	*regs_res;
 	void __iomem	*regs;
 	struct mutex	lock;
-	struct clk	*sclk_fimc_clk;
-	struct clk	*fimc_clk;
-	struct clk	*wb_clk;
-	struct clk	*wb_b_clk;
+	struct clk	*clocks[FIMC_CLKS_MAX];
+	u32		clk_frequency;
 	struct fimc_scaler	sc;
 	struct fimc_driverdata	*ddata;
 	struct exynos_drm_ipp_pol	pol;
@@ -1301,14 +1316,12 @@ static int fimc_clk_ctrl(struct fimc_context *ctx, bool enable)
 	DRM_DEBUG_KMS("%s:enable[%d]\n", __func__, enable);
 
 	if (enable) {
-		clk_enable(ctx->sclk_fimc_clk);
-		clk_enable(ctx->fimc_clk);
-		clk_enable(ctx->wb_clk);
+		clk_prepare_enable(ctx->clocks[FIMC_CLK_GATE]);
+		clk_prepare_enable(ctx->clocks[FIMC_CLK_WB_A]);
 		ctx->suspended = false;
 	} else {
-		clk_disable(ctx->sclk_fimc_clk);
-		clk_disable(ctx->fimc_clk);
-		clk_disable(ctx->wb_clk);
+		clk_disable_unprepare(ctx->clocks[FIMC_CLK_GATE]);
+		clk_disable_unprepare(ctx->clocks[FIMC_CLK_WB_A]);
 		ctx->suspended = true;
 	}
 
@@ -1713,11 +1726,70 @@ static void fimc_ippdrv_stop(struct device *dev, enum drm_exynos_ipp_cmd cmd)
 	fimc_write(cfg, EXYNOS_CIGCTRL);
 }
 
+static void fimc_put_clocks(struct fimc_context *ctx)
+{
+	int i;
+
+	for (i = 0; i < FIMC_CLKS_MAX; i++) {
+		if (IS_ERR(ctx->clocks[i]))
+			continue;
+		clk_put(ctx->clocks[i]);
+		ctx->clocks[i] = ERR_PTR(-EINVAL);
+	}
+}
+
+static int fimc_setup_clocks(struct fimc_context *ctx)
+{
+	struct device *fimc_dev = ctx->ippdrv.dev;
+	struct device *dev;
+	int ret, i;
+
+	for (i = 0; i < FIMC_CLKS_MAX; i++)
+		ctx->clocks[i] = ERR_PTR(-EINVAL);
+
+	for (i = 0; i < FIMC_CLKS_MAX; i++) {
+		if (i == FIMC_CLK_WB_A || i == FIMC_CLK_WB_B)
+			dev = fimc_dev->parent;
+		else
+			dev = fimc_dev;
+
+		ctx->clocks[i] = clk_get(dev, fimc_clock_names[i]);
+		if (IS_ERR(ctx->clocks[i])) {
+			if (i >= FIMC_CLK_MUX)
+				break;
+			ret = PTR_ERR(ctx->clocks[i]);
+			dev_err(fimc_dev, "failed to get clock: %s\n",
+						fimc_clock_names[i]);
+			goto e_clk_free;
+		}
+	}
+
+	/* Optional FIMC LCLK parent clock setting */
+	if (!IS_ERR(ctx->clocks[FIMC_CLK_PARENT])) {
+		ret = clk_set_parent(ctx->clocks[FIMC_CLK_MUX],
+				     ctx->clocks[FIMC_CLK_PARENT]);
+		if (ret < 0) {
+			dev_err(fimc_dev, "failed to set parent.\n");
+			goto e_clk_free;
+		}
+	}
+
+	ret = clk_set_rate(ctx->clocks[FIMC_CLK_LCLK], ctx->clk_frequency);
+	if (ret < 0)
+		goto e_clk_free;
+
+	ret = clk_prepare_enable(ctx->clocks[FIMC_CLK_LCLK]);
+	if (!ret)
+		return ret;
+e_clk_free:
+	fimc_put_clocks(ctx);
+	return ret;
+}
+
 static int fimc_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct fimc_context *ctx;
-	struct clk	*parent_clk;
 	struct resource *res;
 	struct exynos_drm_ippdrv *ippdrv;
 	struct exynos_drm_fimc_pdata *pdata;
@@ -1734,55 +1806,6 @@ static int fimc_probe(struct platform_device *pdev)
 	if (!ctx)
 		return -ENOMEM;
 
-	ddata = (struct fimc_driverdata *)
-		platform_get_device_id(pdev)->driver_data;
-
-	/* clock control */
-	ctx->sclk_fimc_clk = devm_clk_get(dev, "sclk_fimc");
-	if (IS_ERR(ctx->sclk_fimc_clk)) {
-		dev_err(dev, "failed to get src fimc clock.\n");
-		return PTR_ERR(ctx->sclk_fimc_clk);
-	}
-	clk_enable(ctx->sclk_fimc_clk);
-
-	ctx->fimc_clk = devm_clk_get(dev, "fimc");
-	if (IS_ERR(ctx->fimc_clk)) {
-		dev_err(dev, "failed to get fimc clock.\n");
-		clk_disable(ctx->sclk_fimc_clk);
-		return PTR_ERR(ctx->fimc_clk);
-	}
-
-	ctx->wb_clk = devm_clk_get(dev, "pxl_async0");
-	if (IS_ERR(ctx->wb_clk)) {
-		dev_err(dev, "failed to get writeback a clock.\n");
-		clk_disable(ctx->sclk_fimc_clk);
-		return PTR_ERR(ctx->wb_clk);
-	}
-
-	ctx->wb_b_clk = devm_clk_get(dev, "pxl_async1");
-	if (IS_ERR(ctx->wb_b_clk)) {
-		dev_err(dev, "failed to get writeback b clock.\n");
-		clk_disable(ctx->sclk_fimc_clk);
-		return PTR_ERR(ctx->wb_b_clk);
-	}
-
-	parent_clk = devm_clk_get(dev, ddata->parent_clk);
-
-	if (IS_ERR(parent_clk)) {
-		dev_err(dev, "failed to get parent clock.\n");
-		clk_disable(ctx->sclk_fimc_clk);
-		return PTR_ERR(parent_clk);
-	}
-
-	if (clk_set_parent(ctx->sclk_fimc_clk, parent_clk)) {
-		dev_err(dev, "failed to set parent.\n");
-		clk_disable(ctx->sclk_fimc_clk);
-		return -EINVAL;
-	}
-
-	devm_clk_put(dev, parent_clk);
-	clk_set_rate(ctx->sclk_fimc_clk, pdata->clk_rate);
-
 	/* resource memory */
 	ctx->regs_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	ctx->regs = devm_ioremap_resource(dev, ctx->regs_res);
@@ -1804,6 +1827,9 @@ static int fimc_probe(struct platform_device *pdev)
 		return ret;
 	}
 
+	ret = fimc_setup_clocks(ctx);
+	if (ret < 0)
+		goto err_free_irq;
 	/* context initailization */
 	ctx->id = pdev->id;
 	ctx->pol = pdata->pol;
@@ -1820,7 +1846,7 @@ static int fimc_probe(struct platform_device *pdev)
 	ret = fimc_init_prop_list(ippdrv);
 	if (ret < 0) {
 		dev_err(dev, "failed to init property list.\n");
-		goto err_get_irq;
+		goto err_put_clk;
 	}
 
 	DRM_DEBUG_KMS("%s:id[%d]ippdrv[0x%x]\n", __func__, ctx->id,
@@ -1835,16 +1861,18 @@ static int fimc_probe(struct platform_device *pdev)
 	ret = exynos_drm_ippdrv_register(ippdrv);
 	if (ret < 0) {
 		dev_err(dev, "failed to register drm fimc device.\n");
-		goto err_ippdrv_register;
+		goto err_pm_dis;
 	}
 
 	dev_info(&pdev->dev, "drm fimc registered successfully.\n");
 
 	return 0;
 
-err_ippdrv_register:
+err_pm_dis:
 	pm_runtime_disable(dev);
-err_get_irq:
+err_put_clk:
+	fimc_put_clocks(ctx);
+err_free_irq:
 	free_irq(ctx->irq, ctx);
 
 	return ret;
@@ -1859,6 +1887,7 @@ static int fimc_remove(struct platform_device *pdev)
 	exynos_drm_ippdrv_unregister(ippdrv);
 	mutex_destroy(&ctx->lock);
 
+	fimc_put_clocks(ctx);
 	pm_runtime_set_suspended(dev);
 	pm_runtime_disable(dev);