[PATCH v2 1/2] soc: amlogic: add Meson GX VPU Domains driver

[Neil Armstrong]

The Video Processing Unit needs a specific Power Domain powering scheme
this driver handles this as a PM Power Domain driver.

Signed-off-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
---
 drivers/soc/amlogic/Kconfig             |  10 ++
 drivers/soc/amlogic/Makefile            |   1 +
 drivers/soc/amlogic/meson-gx-pwrc-vpu.c | 234 ++++++++++++++++++++++++++++++++
 3 files changed, 245 insertions(+)
 create mode 100644 drivers/soc/amlogic/meson-gx-pwrc-vpu.c

diff --git a/drivers/soc/amlogic/Kconfig b/drivers/soc/amlogic/Kconfig
index ef0b8f6..1621bb2 100644
--- a/drivers/soc/amlogic/Kconfig
+++ b/drivers/soc/amlogic/Kconfig
@@ -9,6 +9,16 @@ config MESON_GX_SOCINFO
 	  Say yes to support decoding of Amlogic Meson GX SoC family
 	  information about the type, package and version.
 
+config MESON_GX_PM_DOMAINS
+	bool "Amlogic Meson GX Power Domains driver"
+	depends on ARCH_MESON || COMPILE_TEST
+	default ARCH_MESON
+	select PM_GENERIC_DOMAINS
+	select PM_GENERIC_DOMAINS_OF
+	help
+	  Say yes to expose Amlogic Meson GX Power Domains as
+	  Generic Power Domains.
+
 config MESON_MX_SOCINFO
 	bool "Amlogic Meson MX SoC Information driver"
 	depends on ARCH_MESON || COMPILE_TEST
diff --git a/drivers/soc/amlogic/Makefile b/drivers/soc/amlogic/Makefile
index 1f5df50..8fa3218 100644
--- a/drivers/soc/amlogic/Makefile
+++ b/drivers/soc/amlogic/Makefile
@@ -1,2 +1,3 @@
 obj-$(CONFIG_MESON_GX_SOCINFO) += meson-gx-socinfo.o
+obj-$(CONFIG_MESON_GX_PM_DOMAINS) += meson-gx-pwrc-vpu.o
 obj-$(CONFIG_MESON_MX_SOCINFO) += meson-mx-socinfo.o
diff --git a/drivers/soc/amlogic/meson-gx-pwrc-vpu.c b/drivers/soc/amlogic/meson-gx-pwrc-vpu.c
new file mode 100644
index 0000000..bf5190b
--- /dev/null
+++ b/drivers/soc/amlogic/meson-gx-pwrc-vpu.c
@@ -0,0 +1,234 @@
+/*
+ * Copyright (c) 2017 BayLibre, SAS
+ * Author: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/pm_domain.h>
+#include <linux/bitfield.h>
+#include <linux/regmap.h>
+#include <linux/mfd/syscon.h>
+#include <linux/reset.h>
+#include <linux/clk.h>
+
+/* AO Offsets */
+
+#define AO_RTI_GEN_PWR_SLEEP0		(0x3a << 2)
+
+#define GEN_PWR_VPU_HDMI		BIT(8)
+#define GEN_PWR_VPU_HDMI_ISO		BIT(9)
+
+/* HHI Offsets */
+
+#define HHI_MEM_PD_REG0			(0x40 << 2)
+#define HHI_VPU_MEM_PD_REG0		(0x41 << 2)
+#define HHI_VPU_MEM_PD_REG1		(0x42 << 2)
+
+struct meson_gx_pwrc_vpu {
+	struct generic_pm_domain genpd;
+	struct regmap *regmap_ao;
+	struct regmap *regmap_hhi;
+	struct reset_control *rstc;
+	struct clk *vpu_clk;
+	struct clk *vapb_clk;
+	bool powered;
+};
+
+static inline
+struct meson_gx_pwrc_vpu *genpd_to_pd(struct generic_pm_domain *d)
+{
+	return container_of(d, struct meson_gx_pwrc_vpu, genpd);
+}
+
+static int meson_gx_pwrc_vpu_power_off(struct generic_pm_domain *genpd)
+{
+	struct meson_gx_pwrc_vpu *pd = genpd_to_pd(genpd);
+	int i;
+
+	regmap_update_bits(pd->regmap_ao, AO_RTI_GEN_PWR_SLEEP0,
+			   GEN_PWR_VPU_HDMI_ISO, GEN_PWR_VPU_HDMI_ISO);
+	udelay(20);
+
+	/* Power Down Memories */
+	for (i = 0; i < 32; i += 2) {
+		regmap_update_bits(pd->regmap_hhi, HHI_VPU_MEM_PD_REG0,
+				   0x2 << i, 0x3 << i);
+		udelay(5);
+	}
+	for (i = 0; i < 32; i += 2) {
+		regmap_update_bits(pd->regmap_hhi, HHI_VPU_MEM_PD_REG1,
+				   0x2 << i, 0x3 << i);
+		udelay(5);
+	}
+	for (i = 8; i < 16; i++) {
+		regmap_update_bits(pd->regmap_hhi, HHI_MEM_PD_REG0,
+				   BIT(i), BIT(i));
+		udelay(5);
+	}
+	udelay(20);
+
+	regmap_update_bits(pd->regmap_ao, AO_RTI_GEN_PWR_SLEEP0,
+			   GEN_PWR_VPU_HDMI, GEN_PWR_VPU_HDMI);
+
+	msleep(20);
+
+	clk_disable_unprepare(pd->vpu_clk);
+	clk_disable_unprepare(pd->vapb_clk);
+
+	pd->powered = false;
+
+	return 0;
+}
+
+static int meson_gx_pwrc_vpu_setup_clk(struct meson_gx_pwrc_vpu *pd)
+{
+	int ret;
+
+	ret = clk_prepare_enable(pd->vpu_clk);
+	if (ret)
+		return ret;
+
+	return clk_prepare_enable(pd->vapb_clk);
+}
+
+static int meson_gx_pwrc_vpu_power_on(struct generic_pm_domain *genpd)
+{
+	struct meson_gx_pwrc_vpu *pd = genpd_to_pd(genpd);
+	int ret;
+	int i;
+
+	regmap_update_bits(pd->regmap_ao, AO_RTI_GEN_PWR_SLEEP0,
+			   GEN_PWR_VPU_HDMI, 0);
+	udelay(20);
+
+	/* Power Up Memories */
+	for (i = 0; i < 32; i += 2) {
+		regmap_update_bits(pd->regmap_hhi, HHI_VPU_MEM_PD_REG0,
+				   0x2 << i, 0);
+		udelay(5);
+	}
+
+	for (i = 0; i < 32; i += 2) {
+		regmap_update_bits(pd->regmap_hhi, HHI_VPU_MEM_PD_REG1,
+				   0x2 << i, 0);
+		udelay(5);
+	}
+
+	for (i = 8; i < 16; i++) {
+		regmap_update_bits(pd->regmap_hhi, HHI_MEM_PD_REG0,
+				   BIT(i), 0);
+		udelay(5);
+	}
+	udelay(20);
+
+	ret = reset_control_assert(pd->rstc);
+	if (ret)
+		return ret;
+
+	regmap_update_bits(pd->regmap_ao, AO_RTI_GEN_PWR_SLEEP0,
+			   GEN_PWR_VPU_HDMI_ISO, 0);
+
+	ret = reset_control_deassert(pd->rstc);
+	if (ret)
+		return ret;
+
+	ret = meson_gx_pwrc_vpu_setup_clk(pd);
+	if (ret)
+		return ret;
+
+	pd->powered = true;
+
+	return 0;
+}
+
+static bool meson_gx_pwrc_vpu_get_power(struct meson_gx_pwrc_vpu *pd)
+{
+	u32 reg;
+
+	regmap_read(pd->regmap_ao, AO_RTI_GEN_PWR_SLEEP0, &reg);
+
+	return (reg & GEN_PWR_VPU_HDMI);
+}
+
+static struct meson_gx_pwrc_vpu vpu_hdmi_pd = {
+	.genpd = {
+		.name = "vpu_hdmi",
+		.power_off = meson_gx_pwrc_vpu_power_off,
+		.power_on = meson_gx_pwrc_vpu_power_on,
+	},
+};
+
+static int meson_gx_pwrc_vpu_probe(struct platform_device *pdev)
+{
+	struct regmap *regmap_ao, *regmap_hhi;
+	struct reset_control *rstc;
+	struct clk *vpu_clk;
+	struct clk *vapb_clk;
+
+	regmap_ao = syscon_node_to_regmap(of_get_parent(pdev->dev.of_node));
+	if (IS_ERR(regmap_ao)) {
+		dev_err(&pdev->dev, "failed to get regmap\n");
+		return PTR_ERR(regmap_ao);
+	}
+
+	regmap_hhi = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
+						     "amlogic,hhi-sysctrl");
+	if (IS_ERR(regmap_hhi)) {
+		dev_err(&pdev->dev, "failed to get HHI regmap\n");
+		return PTR_ERR(regmap_hhi);
+	}
+
+	rstc = devm_reset_control_array_get(&pdev->dev, false, false);
+	if (IS_ERR(rstc)) {
+		dev_err(&pdev->dev, "failed to get reset lines\n");
+		return PTR_ERR(rstc);
+	}
+
+	vpu_clk = devm_clk_get(&pdev->dev, "vpu");
+	if (IS_ERR(vpu_clk)) {
+		dev_err(&pdev->dev, "vpu clock request failed\n");
+		return PTR_ERR(vpu_clk);
+	}
+
+	vapb_clk = devm_clk_get(&pdev->dev, "vapb");
+	if (IS_ERR(vapb_clk)) {
+		dev_err(&pdev->dev, "vapb clock request failed\n");
+		return PTR_ERR(vapb_clk);
+	}
+
+	vpu_hdmi_pd.regmap_ao = regmap_ao;
+	vpu_hdmi_pd.regmap_hhi = regmap_hhi;
+	vpu_hdmi_pd.rstc = rstc;
+	vpu_hdmi_pd.vpu_clk = vpu_clk;
+	vpu_hdmi_pd.vapb_clk = vapb_clk;
+
+	pm_genpd_init(&vpu_hdmi_pd.genpd, &simple_qos_governor,
+		      meson_gx_pwrc_vpu_get_power(&vpu_hdmi_pd));
+
+	return of_genpd_add_provider_simple(pdev->dev.of_node,
+					    &vpu_hdmi_pd.genpd);
+}
+
+static void meson_gx_pwrc_vpu_shutdown(struct platform_device *pdev)
+{
+	if (vpu_hdmi_pd.powered)
+		meson_gx_pwrc_vpu_power_off(&vpu_hdmi_pd.genpd);
+}
+
+static const struct of_device_id meson_gx_pwrc_vpu_match_table[] = {
+	{ .compatible = "amlogic,meson-gx-pwrc-vpu" },
+	{ /* sentinel */ }
+};
+
+static struct platform_driver meson_gx_pwrc_vpu_driver = {
+	.probe	= meson_gx_pwrc_vpu_probe,
+	.shutdown = meson_gx_pwrc_vpu_shutdown,
+	.driver = {
+		.name		= "meson_gx_pwrc_vpu",
+		.of_match_table	= meson_gx_pwrc_vpu_match_table,
+	},
+};
+builtin_platform_driver(meson_gx_pwrc_vpu_driver);
-- 
2.7.4