soc: zte: pm_domains: Prepare for supporting ARMv8 zx2967 family

The ARMv8 zx2967 family (296718, 296716 etc) uses different value
for controlling the power domain on/off registers, Choose the
value depending on the compatible.

Multiple domains are prepared for the family, this patch prepares
the common functions.

Signed-off-by: Baoyou Xie <baoyou.xie@linaro.org>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

4 files changed, 204 insertions, 0 deletions

diff --git a/drivers/soc/zte/Kconfig b/drivers/soc/zte/Kconfig
new file mode 100644
index 000000000000..20bde38ce2f9
--- /dev/null
+++ b/drivers/soc/zte/Kconfig
@@ -0,0 +1,13 @@
+#
+# ZTE SoC drivers
+#
+menuconfig SOC_ZTE
+	bool "ZTE SoC driver support"
+
+if SOC_ZTE
+
+config ZX2967_PM_DOMAINS
+	bool "ZX2967 PM domains"
+	depends on PM_GENERIC_DOMAINS
+
+endif
diff --git a/drivers/soc/zte/Makefile b/drivers/soc/zte/Makefile
new file mode 100644
index 000000000000..8a37f2f7ed27
--- /dev/null
+++ b/drivers/soc/zte/Makefile
@@ -0,0 +1,4 @@
+#
+# ZTE SOC drivers
+#
+obj-$(CONFIG_ZX2967_PM_DOMAINS) += zx2967_pm_domains.o
diff --git a/drivers/soc/zte/zx2967_pm_domains.c b/drivers/soc/zte/zx2967_pm_domains.c
new file mode 100644
index 000000000000..61c8d84bf315
--- /dev/null
+++ b/drivers/soc/zte/zx2967_pm_domains.c
@@ -0,0 +1,143 @@
+/*
+ * Copyright (C) 2017 ZTE Ltd.
+ *
+ * Author: Baoyou Xie <baoyou.xie@linaro.org>
+ * License terms: GNU General Public License (GPL) version 2
+ */
+
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/of.h>
+
+#include "zx2967_pm_domains.h"
+
+#define PCU_DM_CLKEN(zpd)	((zpd)->reg_offset[REG_CLKEN])
+#define PCU_DM_ISOEN(zpd)	((zpd)->reg_offset[REG_ISOEN])
+#define PCU_DM_RSTEN(zpd)	((zpd)->reg_offset[REG_RSTEN])
+#define PCU_DM_PWREN(zpd)	((zpd)->reg_offset[REG_PWREN])
+#define PCU_DM_ACK_SYNC(zpd)	((zpd)->reg_offset[REG_ACK_SYNC])
+
+static void __iomem *pcubase;
+
+static int zx2967_power_on(struct generic_pm_domain *domain)
+{
+	struct zx2967_pm_domain *zpd = (struct zx2967_pm_domain *)domain;
+	unsigned long loop = 1000;
+	u32 val;
+
+	val = readl_relaxed(pcubase + PCU_DM_PWREN(zpd));
+	if (zpd->polarity == PWREN)
+		val |= BIT(zpd->bit);
+	else
+		val &= ~BIT(zpd->bit);
+	writel_relaxed(val, pcubase + PCU_DM_PWREN(zpd));
+
+	do {
+		udelay(1);
+		val = readl_relaxed(pcubase + PCU_DM_ACK_SYNC(zpd))
+				   & BIT(zpd->bit);
+	} while (--loop && !val);
+
+	if (!loop) {
+		pr_err("Error: %s %s fail\n", __func__, domain->name);
+		return -EIO;
+	}
+
+	val = readl_relaxed(pcubase + PCU_DM_RSTEN(zpd));
+	val |= BIT(zpd->bit);
+	writel_relaxed(val, pcubase + PCU_DM_RSTEN(zpd));
+	udelay(5);
+
+	val = readl_relaxed(pcubase + PCU_DM_ISOEN(zpd));
+	val &= ~BIT(zpd->bit);
+	writel_relaxed(val, pcubase + PCU_DM_ISOEN(zpd));
+	udelay(5);
+
+	val = readl_relaxed(pcubase + PCU_DM_CLKEN(zpd));
+	val |= BIT(zpd->bit);
+	writel_relaxed(val, pcubase + PCU_DM_CLKEN(zpd));
+	udelay(5);
+
+	pr_debug("poweron %s\n", domain->name);
+
+	return 0;
+}
+
+static int zx2967_power_off(struct generic_pm_domain *domain)
+{
+	struct zx2967_pm_domain *zpd = (struct zx2967_pm_domain *)domain;
+	unsigned long loop = 1000;
+	u32 val;
+
+	val = readl_relaxed(pcubase + PCU_DM_CLKEN(zpd));
+	val &= ~BIT(zpd->bit);
+	writel_relaxed(val, pcubase + PCU_DM_CLKEN(zpd));
+	udelay(5);
+
+	val = readl_relaxed(pcubase + PCU_DM_ISOEN(zpd));
+	val |= BIT(zpd->bit);
+	writel_relaxed(val, pcubase + PCU_DM_ISOEN(zpd));
+	udelay(5);
+
+	val = readl_relaxed(pcubase + PCU_DM_RSTEN(zpd));
+	val &= ~BIT(zpd->bit);
+	writel_relaxed(val, pcubase + PCU_DM_RSTEN(zpd));
+	udelay(5);
+
+	val = readl_relaxed(pcubase + PCU_DM_PWREN(zpd));
+	if (zpd->polarity == PWREN)
+		val &= ~BIT(zpd->bit);
+	else
+		val |= BIT(zpd->bit);
+	writel_relaxed(val, pcubase + PCU_DM_PWREN(zpd));
+
+	do {
+		udelay(1);
+		val = readl_relaxed(pcubase + PCU_DM_ACK_SYNC(zpd))
+				   & BIT(zpd->bit);
+	} while (--loop && val);
+
+	if (!loop) {
+		pr_err("Error: %s %s fail\n", __func__, domain->name);
+		return -EIO;
+	}
+
+	pr_debug("poweroff %s\n", domain->name);
+
+	return 0;
+}
+
+int zx2967_pd_probe(struct platform_device *pdev,
+		    struct generic_pm_domain **zx_pm_domains,
+		    int domain_num)
+{
+	struct genpd_onecell_data *genpd_data;
+	struct resource *res;
+	int i;
+
+	genpd_data = devm_kzalloc(&pdev->dev, sizeof(*genpd_data), GFP_KERNEL);
+	if (!genpd_data)
+		return -ENOMEM;
+
+	genpd_data->domains = zx_pm_domains;
+	genpd_data->num_domains = domain_num;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	pcubase = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(pcubase)) {
+		dev_err(&pdev->dev, "ioremap fail.\n");
+		return PTR_ERR(pcubase);
+	}
+
+	for (i = 0; i < domain_num; ++i) {
+		zx_pm_domains[i]->power_on = zx2967_power_on;
+		zx_pm_domains[i]->power_off = zx2967_power_off;
+
+		pm_genpd_init(zx_pm_domains[i], NULL, false);
+	}
+
+	of_genpd_add_provider_onecell(pdev->dev.of_node, genpd_data);
+	dev_info(&pdev->dev, "powerdomain init ok\n");
+	return 0;
+}
diff --git a/drivers/soc/zte/zx2967_pm_domains.h b/drivers/soc/zte/zx2967_pm_domains.h
new file mode 100644
index 000000000000..cb46595a7ff3
--- /dev/null
+++ b/drivers/soc/zte/zx2967_pm_domains.h
@@ -0,0 +1,44 @@
+/*
+ * Header for ZTE's Power Domain Driver support
+ *
+ * Copyright (C) 2017 ZTE Ltd.
+ *
+ * Author: Baoyou Xie <baoyou.xie@linaro.org>
+ * License terms: GNU General Public License (GPL) version 2
+ */
+
+#ifndef __ZTE_ZX2967_PM_DOMAIN_H
+#define __ZTE_ZX2967_PM_DOMAIN_H
+
+#include <linux/platform_device.h>
+#include <linux/pm_domain.h>
+
+enum {
+	REG_CLKEN,
+	REG_ISOEN,
+	REG_RSTEN,
+	REG_PWREN,
+	REG_PWRDN,
+	REG_ACK_SYNC,
+
+	/* The size of the array - must be last */
+	REG_ARRAY_SIZE,
+};
+
+enum zx2967_power_polarity {
+	PWREN,
+	PWRDN,
+};
+
+struct zx2967_pm_domain {
+	struct generic_pm_domain dm;
+	const u16 bit;
+	const enum zx2967_power_polarity polarity;
+	const u16 *reg_offset;
+};
+
+int zx2967_pd_probe(struct platform_device *pdev,
+		    struct generic_pm_domain **zx_pm_domains,
+		    int domain_num);
+
+#endif /* __ZTE_ZX2967_PM_DOMAIN_H */