mmc: mediatek: Add subsys clock control for MT8192 msdc

MT8192 msdc is an independent sub system, we need control more bus
clocks for it.
Add support for the additional subsys clocks to allow it to be
configured appropriately.
Signed-off-by: Wenbin Mei <wenbin.mei@mediatek.com>
Reviewed-by: Nicolas Boichat <drinkcat@chromium.org>
Link: https://lore.kernel.org/r/20201014030846.12428-5-wenbin.mei@mediatek.comSigned-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/mtk-sd.c

@@ -35,6 +35,7 @@
 #include "cqhci.h"
 
 #define MAX_BD_NUM          1024
+#define MSDC_NR_CLOCKS      3
 
 /*--------------------------------------------------------------------------*/
 /* Common Definition                                                        */
@@ -425,6 +426,8 @@ struct msdc_host {
 	struct clk *h_clk;      /* msdc h_clk */
 	struct clk *bus_clk;	/* bus clock which used to access register */
 	struct clk *src_clk_cg; /* msdc source clock control gate */
+	struct clk *sys_clk_cg;	/* msdc subsys clock control gate */
+	struct clk_bulk_data bulk_clks[MSDC_NR_CLOCKS];
 	u32 mclk;		/* mmc subsystem clock frequency */
 	u32 src_clk_freq;	/* source clock frequency */
 	unsigned char timing;
@@ -784,6 +787,7 @@ static void msdc_set_busy_timeout(struct msdc_host *host, u64 ns, u64 clks)
 
 static void msdc_gate_clock(struct msdc_host *host)
 {
+	clk_bulk_disable_unprepare(MSDC_NR_CLOCKS, host->bulk_clks);
 	clk_disable_unprepare(host->src_clk_cg);
 	clk_disable_unprepare(host->src_clk);
 	clk_disable_unprepare(host->bus_clk);
@@ -792,10 +796,18 @@ static void msdc_gate_clock(struct msdc_host *host)
 
 static void msdc_ungate_clock(struct msdc_host *host)
 {
+	int ret;
+
 	clk_prepare_enable(host->h_clk);
 	clk_prepare_enable(host->bus_clk);
 	clk_prepare_enable(host->src_clk);
 	clk_prepare_enable(host->src_clk_cg);
+	ret = clk_bulk_prepare_enable(MSDC_NR_CLOCKS, host->bulk_clks);
+	if (ret) {
+		dev_err(host->dev, "Cannot enable pclk/axi/ahb clock gates\n");
+		return;
+	}
+
 	while (!(readl(host->base + MSDC_CFG) & MSDC_CFG_CKSTB))
 		cpu_relax();
 }
@@ -2366,6 +2378,48 @@ static void msdc_of_property_parse(struct platform_device *pdev,
 		host->cqhci = false;
 }
 
+static int msdc_of_clock_parse(struct platform_device *pdev,
+			       struct msdc_host *host)
+{
+	int ret;
+
+	host->src_clk = devm_clk_get(&pdev->dev, "source");
+	if (IS_ERR(host->src_clk))
+		return PTR_ERR(host->src_clk);
+
+	host->h_clk = devm_clk_get(&pdev->dev, "hclk");
+	if (IS_ERR(host->h_clk))
+		return PTR_ERR(host->h_clk);
+
+	host->bus_clk = devm_clk_get_optional(&pdev->dev, "bus_clk");
+	if (IS_ERR(host->bus_clk))
+		host->bus_clk = NULL;
+
+	/*source clock control gate is optional clock*/
+	host->src_clk_cg = devm_clk_get_optional(&pdev->dev, "source_cg");
+	if (IS_ERR(host->src_clk_cg))
+		host->src_clk_cg = NULL;
+
+	host->sys_clk_cg = devm_clk_get_optional(&pdev->dev, "sys_cg");
+	if (IS_ERR(host->sys_clk_cg))
+		host->sys_clk_cg = NULL;
+
+	/* If present, always enable for this clock gate */
+	clk_prepare_enable(host->sys_clk_cg);
+
+	host->bulk_clks[0].id = "pclk_cg";
+	host->bulk_clks[1].id = "axi_cg";
+	host->bulk_clks[2].id = "ahb_cg";
+	ret = devm_clk_bulk_get_optional(&pdev->dev, MSDC_NR_CLOCKS,
+					 host->bulk_clks);
+	if (ret) {
+		dev_err(&pdev->dev, "Cannot get pclk/axi/ahb clock gates\n");
+		return ret;
+	}
+
+	return 0;
+}
+
 static int msdc_drv_probe(struct platform_device *pdev)
 {
 	struct mmc_host *mmc;
@@ -2405,25 +2459,9 @@ static int msdc_drv_probe(struct platform_device *pdev)
 	if (ret)
 		goto host_free;
 
-	host->src_clk = devm_clk_get(&pdev->dev, "source");
-	if (IS_ERR(host->src_clk)) {
-		ret = PTR_ERR(host->src_clk);
-		goto host_free;
-	}
-
-	host->h_clk = devm_clk_get(&pdev->dev, "hclk");
-	if (IS_ERR(host->h_clk)) {
-		ret = PTR_ERR(host->h_clk);
+	ret = msdc_of_clock_parse(pdev, host);
+	if (ret)
 		goto host_free;
-	}
-
-	host->bus_clk = devm_clk_get(&pdev->dev, "bus_clk");
-	if (IS_ERR(host->bus_clk))
-		host->bus_clk = NULL;
-	/*source clock control gate is optional clock*/
-	host->src_clk_cg = devm_clk_get(&pdev->dev, "source_cg");
-	if (IS_ERR(host->src_clk_cg))
-		host->src_clk_cg = NULL;
 
 	host->reset = devm_reset_control_get_optional_exclusive(&pdev->dev,
 								"hrst");