[5.10.y-cip,v2,2/4] soc: renesas: Add PWC support for RZ/V2M

Commit Message

Fabrizio Castro July 4, 2023, 3:34 p.m. UTC

Commit 0c56f949f626e59ef7c5b18e2706fed2a6afc4a2 upstream.

The Renesas RZ/V2M External Power Sequence Controller (PWC)
IP is capable of:
* external power supply on/off sequence generation
* on/off signal generation for the LPDDR4 core power supply (LPVDD)
* key input signals processing
* general-purpose output pins

Add the corresponding device driver.

Signed-off-by: Fabrizio Castro <[e-mail]>
Reviewed-by: Geert Uytterhoeven <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Geert Uytterhoeven <[e-mail]>
[Fabrizio: - Switched to using pm_power_off as devm_register
	     power_off_handler is not availble in v5.10.y-cip
	   - priv_pwc is now static to pwc-rzv2m.c as the
	     pm_power_off callback cannot access private data ]
Signed-off-by: Fabrizio Castro <[e-mail]>
---

v2: Moved symname definition to right before it gets used

 drivers/soc/renesas/Kconfig     |   4 +
 drivers/soc/renesas/Makefile    |   1 +
 drivers/soc/renesas/pwc-rzv2m.c | 151 ++++++++++++++++++++++++++++++++
 3 files changed, 156 insertions(+)
 create mode 100644 drivers/soc/renesas/pwc-rzv2m.c

Patch

diff --git a/drivers/soc/renesas/Kconfig b/drivers/soc/renesas/Kconfig
index a2d37a682dfc..dcc0d2ae1b2c 100644
--- a/drivers/soc/renesas/Kconfig
+++ b/drivers/soc/renesas/Kconfig
@@ -306,11 +306,15 @@  config ARCH_R9A09G011
 	bool "ARM64 Platform support for RZ/V2M"
 	select PM
 	select PM_GENERIC_DOMAINS
+	select PWC_RZV2M
 	help
 	  This enables support for the Renesas RZ/V2M SoC.
 
 endif # ARM64
 
+config PWC_RZV2M
+	bool "Renesas RZ/V2M PWC support" if COMPILE_TEST
+
 config RST_RCAR
 	bool "Reset Controller support for R-Car" if COMPILE_TEST
 
diff --git a/drivers/soc/renesas/Makefile b/drivers/soc/renesas/Makefile
index 9b29bed2a597..c571e8ef9192 100644
--- a/drivers/soc/renesas/Makefile
+++ b/drivers/soc/renesas/Makefile
@@ -30,6 +30,7 @@  obj-$(CONFIG_ARCH_R9A06G032)	+= r9a06g032-smp.o
 endif
 
 # Family
+obj-$(CONFIG_PWC_RZV2M)		+= pwc-rzv2m.o
 obj-$(CONFIG_RST_RCAR)		+= rcar-rst.o
 obj-$(CONFIG_SYSC_RCAR)		+= rcar-sysc.o
 obj-$(CONFIG_SYSC_RMOBILE)	+= rmobile-sysc.o
diff --git a/drivers/soc/renesas/pwc-rzv2m.c b/drivers/soc/renesas/pwc-rzv2m.c
new file mode 100644
index 000000000000..075db5d5640c
--- /dev/null
+++ b/drivers/soc/renesas/pwc-rzv2m.c
@@ -0,0 +1,151 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2023 Renesas Electronics Corporation
+ */
+
+#include <linux/delay.h>
+#include <linux/gpio/driver.h>
+#include <linux/kallsyms.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/reboot.h>
+
+#define PWC_PWCRST			0x00
+#define PWC_PWCCKEN			0x04
+#define PWC_PWCCTL			0x50
+#define PWC_GPIO			0x80
+
+#define PWC_PWCRST_RSTSOFTAX		0x1
+#define PWC_PWCCKEN_ENGCKMAIN		0x1
+#define PWC_PWCCTL_PWOFF		0x1
+
+struct rzv2m_pwc_priv {
+	void __iomem *base;
+	struct device *dev;
+	struct gpio_chip gp;
+	DECLARE_BITMAP(ch_en_bits, 2);
+};
+
+static struct rzv2m_pwc_priv *priv_pwc;
+
+static void rzv2m_pwc_gpio_set(struct gpio_chip *chip, unsigned int offset,
+			       int value)
+{
+	struct rzv2m_pwc_priv *priv = gpiochip_get_data(chip);
+	u32 reg;
+
+	/* BIT 16 enables write to BIT 0, and BIT 17 enables write to BIT 1 */
+	reg = BIT(offset + 16);
+	if (value)
+		reg |= BIT(offset);
+
+	writel(reg, priv->base + PWC_GPIO);
+
+	assign_bit(offset, priv->ch_en_bits, value);
+}
+
+static int rzv2m_pwc_gpio_get(struct gpio_chip *chip, unsigned int offset)
+{
+	struct rzv2m_pwc_priv *priv = gpiochip_get_data(chip);
+
+	return test_bit(offset, priv->ch_en_bits);
+}
+
+static int rzv2m_pwc_gpio_direction_output(struct gpio_chip *gc,
+					   unsigned int nr, int value)
+{
+	if (nr > 1)
+		return -EINVAL;
+
+	rzv2m_pwc_gpio_set(gc, nr, value);
+
+	return 0;
+}
+
+static const struct gpio_chip rzv2m_pwc_gc = {
+	.label = "gpio_rzv2m_pwc",
+	.owner = THIS_MODULE,
+	.get = rzv2m_pwc_gpio_get,
+	.set = rzv2m_pwc_gpio_set,
+	.direction_output = rzv2m_pwc_gpio_direction_output,
+	.can_sleep = false,
+	.ngpio = 2,
+	.base = -1,
+};
+
+static void rzv2m_pwc_poweroff(void)
+{
+	writel(PWC_PWCRST_RSTSOFTAX, priv_pwc->base + PWC_PWCRST);
+	writel(PWC_PWCCKEN_ENGCKMAIN, priv_pwc->base + PWC_PWCCKEN);
+	writel(PWC_PWCCTL_PWOFF, priv_pwc->base + PWC_PWCCTL);
+
+	mdelay(150);
+
+	dev_err(priv_pwc->dev, "Failed to power off the system");
+}
+
+static int rzv2m_pwc_probe(struct platform_device *pdev)
+{
+	struct rzv2m_pwc_priv *priv;
+	int ret;
+
+	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(priv->base))
+		return PTR_ERR(priv->base);
+
+	/*
+	 * The register used by this driver cannot be read, therefore set the
+	 * outputs to their default values and initialize priv->ch_en_bits
+	 * accordingly. BIT 16 enables write to BIT 0, BIT 17 enables write to
+	 * BIT 1, and the default value of both BIT 0 and BIT 1 is 0.
+	 */
+	writel(BIT(17) | BIT(16), priv->base + PWC_GPIO);
+	bitmap_zero(priv->ch_en_bits, 2);
+
+	priv->gp = rzv2m_pwc_gc;
+	priv->gp.parent = pdev->dev.parent;
+	priv->gp.of_node = pdev->dev.of_node;
+
+	ret = devm_gpiochip_add_data(&pdev->dev, &priv->gp, priv);
+	if (ret)
+		return ret;
+
+	if (device_property_read_bool(&pdev->dev, "renesas,rzv2m-pwc-power")) {
+		if (pm_power_off) {
+			char symname[KSYM_NAME_LEN];
+
+			lookup_symbol_name((ulong)pm_power_off, symname);
+			dev_err(&pdev->dev, "pm_power_off already claimed %p %s",
+				pm_power_off, symname);
+			return -EBUSY;
+
+		}
+		priv_pwc = priv;
+		pm_power_off = rzv2m_pwc_poweroff;
+	}
+
+	return ret;
+}
+
+static const struct of_device_id rzv2m_pwc_of_match[] = {
+	{ .compatible = "renesas,rzv2m-pwc" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, rzv2m_pwc_of_match);
+
+static struct platform_driver rzv2m_pwc_driver = {
+	.probe = rzv2m_pwc_probe,
+	.driver = {
+		.name = "rzv2m_pwc",
+		.of_match_table = of_match_ptr(rzv2m_pwc_of_match),
+	},
+};
+module_platform_driver(rzv2m_pwc_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Fabrizio Castro <[e-mail]>");
+MODULE_DESCRIPTION("Renesas RZ/V2M PWC driver");