linux-kernel - [PATCH v6 11/14] soc: mediatek: Add subsys clock control for bus protection

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Message-ID: <1560998286-9189-12-git-send-email-weiyi.lu@mediatek.com>
Date:   Thu, 20 Jun 2019 10:38:03 +0800
From:   Weiyi Lu <weiyi.lu@...iatek.com>
To:     Nicolas Boichat <drinkcat@...omium.org>,
        Matthias Brugger <matthias.bgg@...il.com>,
        Rob Herring <robh@...nel.org>
CC:     James Liao <jamesjj.liao@...iatek.com>,
        Fan Chen <fan.chen@...iatek.com>,
        <linux-arm-kernel@...ts.infradead.org>,
        <linux-kernel@...r.kernel.org>,
        <linux-mediatek@...ts.infradead.org>,
        <srv_heupstream@...iatek.com>, Weiyi Lu <weiyi.lu@...iatek.com>,
        Yong Wu <yong.wu@...iatek.com>
Subject: [PATCH v6 11/14] soc: mediatek: Add subsys clock control for bus protection

Add subsys CG control flow before/after the bus protect control
due to bus protection need SMI bus relative CGs enabled to feedback
its ack.

Signed-off-by: Weiyi Lu <weiyi.lu@...iatek.com>
---
 drivers/soc/mediatek/mtk-scpsys.c | 72 +++++++++++++++++++++++++++++++++++++--
 1 file changed, 70 insertions(+), 2 deletions(-)

diff --git a/drivers/soc/mediatek/mtk-scpsys.c b/drivers/soc/mediatek/mtk-scpsys.c
index 10c2440..74fd981 100644
--- a/drivers/soc/mediatek/mtk-scpsys.c
+++ b/drivers/soc/mediatek/mtk-scpsys.c
@@ -108,6 +108,7 @@ enum clk_id {
 };
 
 #define MAX_CLKS	3
+#define MAX_SUBSYS_CLKS 10
 
 /**
  * struct scp_domain_data - scp domain data for power on/off flow
@@ -120,6 +121,8 @@ enum clk_id {
  * @clk_id: The basic clocks required by this power domain.
  * @basic_clk_id: provide the same purpose with field "clk_id"
  *                by declaring basic clock prefix name rather than clk_id.
+ * @subsys_clk_prefix: The prefix name of the clocks need to be enabled
+ *                     before releasing bus protection.
  * @caps: The flag for active wake-up action.
  * @bp_table: The mask table for multiple step bus protection.
  */
@@ -132,6 +135,7 @@ struct scp_domain_data {
 	u32 bus_prot_mask;
 	enum clk_id clk_id[MAX_CLKS];
 	const char *basic_clk_id[MAX_CLKS];
+	const char *subsys_clk_prefix;
 	u8 caps;
 	struct bus_prot bp_table[MAX_STEPS];
 };
@@ -142,6 +146,7 @@ struct scp_domain {
 	struct generic_pm_domain genpd;
 	struct scp *scp;
 	struct clk *clk[MAX_CLKS];
+	struct clk *subsys_clk[MAX_SUBSYS_CLKS];
 	const struct scp_domain_data *data;
 	struct regulator *supply;
 };
@@ -347,16 +352,22 @@ static int scpsys_power_on(struct generic_pm_domain *genpd)
 	val |= PWR_RST_B_BIT;
 	writel(val, ctl_addr);
 
-	ret = scpsys_sram_enable(scpd, ctl_addr);
+	ret = scpsys_clk_enable(scpd->subsys_clk, MAX_SUBSYS_CLKS);
 	if (ret < 0)
 		goto err_pwr_ack;
 
+	ret = scpsys_sram_enable(scpd, ctl_addr);
+	if (ret < 0)
+		goto err_sram;
+
 	ret = scpsys_bus_protect_disable(scpd);
 	if (ret < 0)
-		goto err_pwr_ack;
+		goto err_sram;
 
 	return 0;
 
+err_sram:
+	scpsys_clk_disable(scpd->subsys_clk, MAX_SUBSYS_CLKS);
 err_pwr_ack:
 	scpsys_clk_disable(scpd->clk, MAX_CLKS);
 err_clk:
@@ -383,6 +394,8 @@ static int scpsys_power_off(struct generic_pm_domain *genpd)
 	if (ret < 0)
 		goto out;
 
+	scpsys_clk_disable(scpd->subsys_clk, MAX_SUBSYS_CLKS);
+
 	/* subsys power off */
 	val = readl(ctl_addr) | PWR_ISO_BIT;
 	writel(val, ctl_addr);
@@ -419,6 +432,48 @@ static int scpsys_power_off(struct generic_pm_domain *genpd)
 	return ret;
 }
 
+static int init_subsys_clks(struct platform_device *pdev,
+		const char *prefix, struct clk **clk)
+{
+	struct device_node *node = pdev->dev.of_node;
+	u32 prefix_len, sub_clk_cnt = 0;
+	struct property *prop;
+	const char *clk_name;
+
+	if (!node) {
+		dev_err(&pdev->dev, "Cannot find scpsys node: %ld\n",
+			PTR_ERR(node));
+		return PTR_ERR(node);
+	}
+
+	prefix_len = strlen(prefix);
+
+	of_property_for_each_string(node, "clock-names", prop, clk_name) {
+		if (!strncmp(clk_name, prefix, prefix_len) &&
+				(clk_name[prefix_len] == '-')) {
+			if (sub_clk_cnt >= MAX_SUBSYS_CLKS) {
+				dev_err(&pdev->dev,
+					"subsys clk out of range %d\n",
+					sub_clk_cnt);
+				return -ENOMEM;
+			}
+
+			clk[sub_clk_cnt] = devm_clk_get(&pdev->dev,
+						clk_name);
+
+			if (IS_ERR(clk)) {
+				dev_err(&pdev->dev,
+					"Subsys clk read fail %ld\n",
+					PTR_ERR(clk));
+				return PTR_ERR(clk);
+			}
+			sub_clk_cnt++;
+		}
+	}
+
+	return sub_clk_cnt;
+}
+
 static void init_clks(struct platform_device *pdev, struct clk **clk)
 {
 	int i;
@@ -506,6 +561,7 @@ static struct scp *init_scp(struct platform_device *pdev,
 		struct scp_domain *scpd = &scp->domains[i];
 		struct generic_pm_domain *genpd = &scpd->genpd;
 		const struct scp_domain_data *data = &scp_domain_data[i];
+		int clk_cnt;
 
 		pd_data->domains[i] = genpd;
 		scpd->scp = scp;
@@ -534,6 +590,18 @@ static struct scp *init_scp(struct platform_device *pdev,
 						data->basic_clk_id[j]);
 		}
 
+		if (data->subsys_clk_prefix) {
+			clk_cnt = init_subsys_clks(pdev,
+					data->subsys_clk_prefix,
+					scpd->subsys_clk);
+			if (clk_cnt < 0) {
+				dev_err(&pdev->dev,
+					"%s: subsys clk unavailable\n",
+					data->name);
+				return ERR_PTR(clk_cnt);
+			}
+		}
+
 		genpd->name = data->name;
 		genpd->power_off = scpsys_power_off;
 		genpd->power_on = scpsys_power_on;
-- 
1.8.1.1.dirty