msm_11ad: add rfclk3 clock handling

On platforms where the power supply for 11AD is external
the wil6210 device can control the rfclk3 clock using a GPIO.
wil6210 driver has to enable the clock during device reset
to guarantee the rfclk3 is on for bootloader activity.
After the wil6210 device is up, the wil6210 driver needs to
leave only the pin clock enabled, to allow the device to
toggle it.

Change-Id: I0f6181d18268f7a2f615155525fbed0f0fe7572a
CRs-Fixed: 986130
Signed-off-by: Maya Erez <merez@codeaurora.org>

2 files changed, 191 insertions, 6 deletions

diff --git a/Documentation/devicetree/bindings/arm/msm/wil6210.txt b/Documentation/devicetree/bindings/arm/msm/wil6210.txt
index 1840965b978f..b381bdebdfc9 100644
--- a/Documentation/devicetree/bindings/arm/msm/wil6210.txt
+++ b/Documentation/devicetree/bindings/arm/msm/wil6210.txt
@@ -24,6 +24,10 @@ Optional properties:
 - qcom,use-ext-supply: Boolean flag to indicate if 11ad SIP uses external power supply
 - vdd-supply: phandle to 11ad VDD regulator node
 - vddio-supply: phandle to 11ad VDDIO regulator node
+- qcom,use-ext-clocks: Boolean flag to indicate if 11ad SIP uses external clocks
+- clocks	    : List of phandle and clock specifier pairs
+- clock-names       : List of clock input name strings sorted in the same
+		      order as the clocks property.
 
 Example:
 	wil6210: qcom,wil6210 {
@@ -40,5 +44,9 @@ Example:
 		qcom,use-ext-supply;
 		vdd-supply= <&pm8998_s7>;
 		vddio-supply= <&pm8998_s5>;
+		qcom,use-ext-clocks;
+		clocks = <&clock_gcc clk_rf_clk3>,
+			 <&clock_gcc clk_rf_clk3_pin>;
+		clock-names = "rf_clk3_clk", "rf_clk3_pin_clk";
 	};
 
diff --git a/drivers/platform/msm/msm_11ad/msm_11ad.c b/drivers/platform/msm/msm_11ad/msm_11ad.c
index 35f461f4fcac..203e0c4b4339 100644
--- a/drivers/platform/msm/msm_11ad/msm_11ad.c
+++ b/drivers/platform/msm/msm_11ad/msm_11ad.c
@@ -25,6 +25,7 @@
 #include <soc/qcom/ramdump.h>
 #include <soc/qcom/memory_dump.h>
 #include <linux/regulator/consumer.h>
+#include <linux/clk.h>
 #include "wil_platform.h"
 #include "msm_11ad.h"
 
@@ -64,6 +65,12 @@ struct msm11ad_vreg {
 	bool enabled;
 };
 
+struct msm11ad_clk {
+	const char *name;
+	struct clk *clk;
+	bool enabled;
+};
+
 struct msm11ad_ctx {
 	struct list_head list;
 	struct device *dev; /* for platform device */
@@ -95,8 +102,12 @@ struct msm11ad_ctx {
 	void *ramdump_addr;
 	struct msm_dump_data dump_data;
 	struct ramdump_device *ramdump_dev;
+
+	/* external vregs and clocks */
 	struct msm11ad_vreg vdd;
 	struct msm11ad_vreg vddio;
+	struct msm11ad_clk rf_clk3;
+	struct msm11ad_clk rf_clk3_pin;
 };
 
 static LIST_HEAD(dev_list);
@@ -154,6 +165,48 @@ static int msm_11ad_release_vreg(struct device *dev, struct msm11ad_vreg *vreg)
 	return 0;
 }
 
+static int msm_11ad_init_clk(struct device *dev, struct msm11ad_clk *clk,
+			     const char *name)
+{
+	int rc = 0;
+
+	clk->name = kstrdup(name, GFP_KERNEL);
+	if (!clk->name)
+		return -ENOMEM;
+
+	clk->clk = devm_clk_get(dev, name);
+	if (IS_ERR(clk->clk)) {
+		rc = PTR_ERR(clk->clk);
+		if (rc == -ENOENT)
+			rc = -EPROBE_DEFER;
+		dev_err(dev, "%s: failed to get %s rc %d",
+				__func__, name, rc);
+		kfree(clk->name);
+		clk->clk = NULL;
+		goto out;
+	}
+
+	dev_info(dev, "%s: %s initialized successfully\n", __func__, name);
+
+out:
+	return rc;
+}
+
+static int msm_11ad_release_clk(struct device *dev, struct msm11ad_clk *clk)
+{
+	if (!clk || !clk->clk)
+		return 0;
+
+	dev_info(dev, "%s: %s released\n", __func__, clk->name);
+
+	devm_clk_put(dev, clk->clk);
+	clk->clk = NULL;
+
+	kfree(clk->name);
+
+	return 0;
+}
+
 static int msm_11ad_init_vregs(struct msm11ad_ctx *ctx)
 {
 	int rc;
@@ -324,6 +377,92 @@ out:
 	return 0;
 }
 
+static int msm_11ad_enable_clk(struct msm11ad_ctx *ctx,
+				struct msm11ad_clk *clk)
+{
+	struct device *dev = ctx->dev;
+	int rc = 0;
+
+	if (!clk || !clk->clk || clk->enabled)
+		goto out;
+
+	rc = clk_prepare_enable(clk->clk);
+	if (rc) {
+		dev_err(dev, "%s: failed to enable %s, rc(%d)\n",
+			__func__, clk->name, rc);
+		goto out;
+	}
+	clk->enabled = true;
+
+	dev_dbg(dev, "%s: %s enabled\n", __func__, clk->name);
+
+out:
+	return rc;
+}
+
+static void msm_11ad_disable_clk(struct msm11ad_ctx *ctx,
+				struct msm11ad_clk *clk)
+{
+	struct device *dev = ctx->dev;
+
+	if (!clk || !clk->clk || !clk->enabled)
+		goto out;
+
+	clk_disable_unprepare(clk->clk);
+	clk->enabled = false;
+
+	dev_dbg(dev, "%s: %s disabled\n", __func__, clk->name);
+
+out:
+	return;
+}
+
+static int msm_11ad_enable_clocks(struct msm11ad_ctx *ctx)
+{
+	int rc;
+
+	rc = msm_11ad_enable_clk(ctx, &ctx->rf_clk3);
+	if (rc)
+		return rc;
+
+	rc = msm_11ad_enable_clk(ctx, &ctx->rf_clk3_pin);
+	if (rc)
+		msm_11ad_disable_clk(ctx, &ctx->rf_clk3);
+
+	return rc;
+}
+
+static int msm_11ad_init_clocks(struct msm11ad_ctx *ctx)
+{
+	int rc;
+	struct device *dev = ctx->dev;
+
+	if (!of_property_read_bool(dev->of_node, "qcom,use-ext-clocks"))
+		return 0;
+
+	rc = msm_11ad_init_clk(dev, &ctx->rf_clk3, "rf_clk3_clk");
+	if (rc)
+		return rc;
+
+	rc = msm_11ad_init_clk(dev, &ctx->rf_clk3_pin, "rf_clk3_pin_clk");
+	if (rc)
+		msm_11ad_release_clk(ctx->dev, &ctx->rf_clk3);
+
+	return rc;
+}
+
+static void msm_11ad_release_clocks(struct msm11ad_ctx *ctx)
+{
+	msm_11ad_release_clk(ctx->dev, &ctx->rf_clk3_pin);
+	msm_11ad_release_clk(ctx->dev, &ctx->rf_clk3);
+}
+
+static void msm_11ad_disable_clocks(struct msm11ad_ctx *ctx)
+{
+	msm_11ad_disable_clk(ctx, &ctx->rf_clk3_pin);
+	msm_11ad_disable_clk(ctx, &ctx->rf_clk3);
+}
+
 static int ops_suspend(void *handle)
 {
 	int rc;
@@ -354,6 +493,8 @@ static int ops_suspend(void *handle)
 	if (ctx->sleep_clk_en >= 0)
 		gpio_direction_output(ctx->sleep_clk_en, 0);
 
+	msm_11ad_disable_clocks(ctx);
+
 	msm_11ad_disable_vregs(ctx);
 
 	return rc;
@@ -378,6 +519,12 @@ static int ops_resume(void *handle)
 		return rc;
 	}
 
+	rc = msm_11ad_enable_clocks(ctx);
+	if (rc) {
+		dev_err(ctx->dev, "msm_11ad_enable_clocks failed :%d\n", rc);
+		goto err_disable_vregs;
+	}
+
 	if (ctx->sleep_clk_en >= 0)
 		gpio_direction_output(ctx->sleep_clk_en, 1);
 
@@ -413,6 +560,8 @@ err_disable_power:
 	if (ctx->sleep_clk_en >= 0)
 		gpio_direction_output(ctx->sleep_clk_en, 0);
 
+	msm_11ad_disable_clocks(ctx);
+err_disable_vregs:
 	msm_11ad_disable_vregs(ctx);
 
 	return rc;
@@ -701,15 +850,25 @@ static int msm_11ad_probe(struct platform_device *pdev)
 	/* turn device on */
 	rc = msm_11ad_init_vregs(ctx);
 	if (rc) {
-		dev_err(ctx->dev, "msm_11ad_init_vregs failed :%d\n",
-			rc);
+		dev_err(ctx->dev, "msm_11ad_init_vregs failed: %d\n", rc);
 		return rc;
 	}
 	rc = msm_11ad_enable_vregs(ctx);
 	if (rc) {
-		dev_err(ctx->dev, "msm_11ad_enable_vregs failed :%d\n",
-			rc);
-		goto out_vreg;
+		dev_err(ctx->dev, "msm_11ad_enable_vregs failed: %d\n", rc);
+		goto out_vreg_clk;
+	}
+
+	rc = msm_11ad_init_clocks(ctx);
+	if (rc) {
+		dev_err(ctx->dev, "msm_11ad_init_clocks failed: %d\n", rc);
+		goto out_vreg_clk;
+	}
+
+	rc = msm_11ad_enable_clocks(ctx);
+	if (rc) {
+		dev_err(ctx->dev, "msm_11ad_enable_clocks failed: %d\n", rc);
+		goto out_vreg_clk;
 	}
 
 	if (ctx->gpio_en >= 0) {
@@ -801,8 +960,10 @@ out_set:
 		gpio_free(ctx->gpio_en);
 out_req:
 	ctx->gpio_en = -EINVAL;
+out_vreg_clk:
+	msm_11ad_disable_clocks(ctx);
+	msm_11ad_release_clocks(ctx);
 	msm_11ad_disable_vregs(ctx);
-out_vreg:
 	msm_11ad_release_vregs(ctx);
 
 	return rc;
@@ -827,6 +988,8 @@ static int msm_11ad_remove(struct platform_device *pdev)
 	if (ctx->sleep_clk_en >= 0)
 		gpio_free(ctx->sleep_clk_en);
 
+	msm_11ad_disable_clocks(ctx);
+	msm_11ad_release_clocks(ctx);
 	msm_11ad_disable_vregs(ctx);
 	msm_11ad_release_vregs(ctx);
 
@@ -927,6 +1090,20 @@ static int ops_notify(void *handle, enum wil_platform_event evt)
 	case WIL_PLATFORM_EVT_FW_CRASH:
 		rc = msm_11ad_notify_crash(ctx);
 		break;
+	case WIL_PLATFORM_EVT_PRE_RESET:
+		/*
+		 * Enable rf_clk3 clock before resetting the device to ensure
+		 * stable ref clock during the device reset
+		 */
+		rc = msm_11ad_enable_clk(ctx, &ctx->rf_clk3);
+		break;
+	case WIL_PLATFORM_EVT_FW_RDY:
+		/*
+		 * Disable rf_clk3 clock after the device is up to allow
+		 * the device to control it via its GPIO for power saving
+		 */
+		msm_11ad_disable_clk(ctx, &ctx->rf_clk3);
+		break;
 	default:
 		pr_debug("%s: Unhandled event %d\n", __func__, evt);
 		break;