[PATCH 7/7] pinctrl: tegra: Add driver to configure voltage and power state of io pads

[Laxman Dewangan <ldewangan@nvidia.com>]

NVIDIA Tegra210 supports the IO pads which can operate at 1.8V
or 3.3V I/O voltage levels. Also the IO pads can be configured
for power down state if it is not used. SW needs to configure the
voltage level of IO pads based on IO rail voltage and its power
state based on platform usage.

The voltage and power state configurations of pads are provided
through pin control frameworks. Add pin control driver for Tegra's
IO pads' voltage and power state configurations.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
---
 drivers/pinctrl/tegra/Kconfig                   |  11 +
 drivers/pinctrl/tegra/Makefile                  |   1 +
 drivers/pinctrl/tegra/pinctrl-tegra210-io-pad.c | 302 ++++++++++++++++++++++++
 3 files changed, 314 insertions(+)
 create mode 100644 drivers/pinctrl/tegra/pinctrl-tegra210-io-pad.c

diff --git a/drivers/pinctrl/tegra/Kconfig b/drivers/pinctrl/tegra/Kconfig
index 24e20cc..37b85d7 100644
--- a/drivers/pinctrl/tegra/Kconfig
+++ b/drivers/pinctrl/tegra/Kconfig
@@ -23,6 +23,17 @@ config PINCTRL_TEGRA210
 	bool
 	select PINCTRL_TEGRA
 
+config PINCTRL_TEGRA210_IO_PAD
+	bool "Tegra210 IO pad Control Driver"
+	depends on ARCH_TEGRA
+	select PINCONF
+	select PINMUX
+	help
+	  NVIDIA Tegra210 SoC has IO pads which supports mult-voltage level
+	  of interfacing. The voltage of IO pads are SW configurable based
+	  on IO rail of that pads. This driver provides the interface to
+	  change IO pad voltage and power state via pincontrol interface.
+
 config PINCTRL_TEGRA_XUSB
 	def_bool y if ARCH_TEGRA
 	select GENERIC_PHY
diff --git a/drivers/pinctrl/tegra/Makefile b/drivers/pinctrl/tegra/Makefile
index a927379..90f4000 100644
--- a/drivers/pinctrl/tegra/Makefile
+++ b/drivers/pinctrl/tegra/Makefile
@@ -4,4 +4,5 @@ obj-$(CONFIG_PINCTRL_TEGRA30)		+= pinctrl-tegra30.o
 obj-$(CONFIG_PINCTRL_TEGRA114)		+= pinctrl-tegra114.o
 obj-$(CONFIG_PINCTRL_TEGRA124)		+= pinctrl-tegra124.o
 obj-$(CONFIG_PINCTRL_TEGRA210)		+= pinctrl-tegra210.o
+obj-$(CONFIG_PINCTRL_TEGRA210_IO_PAD)	+= pinctrl-tegra210-io-pad.o
 obj-$(CONFIG_PINCTRL_TEGRA_XUSB)	+= pinctrl-tegra-xusb.o
diff --git a/drivers/pinctrl/tegra/pinctrl-tegra210-io-pad.c b/drivers/pinctrl/tegra/pinctrl-tegra210-io-pad.c
new file mode 100644
index 0000000..4959c19
--- /dev/null
+++ b/drivers/pinctrl/tegra/pinctrl-tegra210-io-pad.c
@@ -0,0 +1,302 @@
+/*
+ * Generic ADC thermal driver
+ *
+ * Copyright (C) 2016 NVIDIA CORPORATION. All rights reserved.
+ *
+ * Author: Laxman Dewangan <ldewangan@nvidia.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/pinctrl/pinctrl.h>
+#include <linux/pinctrl/pinconf-generic.h>
+#include <linux/pinctrl/pinconf.h>
+#include <linux/pinctrl/pinmux.h>
+#include <linux/platform_device.h>
+#include <linux/delay.h>
+#include <soc/tegra/pmc.h>
+
+#include "../core.h"
+#include "../pinconf.h"
+#include "../pinctrl-utils.h"
+
+enum tegra_io_rail_pads_params {
+	TEGRA_IO_RAIL_VOLTAGE = PIN_CONFIG_END + 1,
+	TEGRA_IO_PAD_DEEP_POWER_DOWN,
+};
+
+static const struct pinconf_generic_params tegra_io_pads_cfg_params[] = {
+	{
+		.property = "nvidia,io-rail-voltage",
+		.param = TEGRA_IO_RAIL_VOLTAGE,
+	}, {
+		.property = "nvidia,io-pad-deep-power-down",
+		.param = TEGRA_IO_PAD_DEEP_POWER_DOWN,
+	},
+};
+
+struct tegra_io_pads_cfg_info {
+	const char *name;
+	const unsigned int pins[1];
+	int io_rail_id;
+};
+
+#define TEGRA210_PAD_INFO_TABLE(_entry_)		\
+	_entry_(0, "audio", AUDIO),			\
+	_entry_(1, "audio-hv", AUDIO_HV),	\
+	_entry_(2, "cam", CAM),			\
+	_entry_(3, "csia", CSIA),			\
+	_entry_(4, "csib", CSIB),			\
+	_entry_(5, "csic", CSIC),			\
+	_entry_(6, "csid", CSID),			\
+	_entry_(7, "csie", CSIE),			\
+	_entry_(8, "csif", CSIF),			\
+	_entry_(9, "dbg", DBG),			\
+	_entry_(10, "debug-nonao", DBG_NONAO), \
+	_entry_(11, "dmic", DMIC),			\
+	_entry_(12, "dp", DP),				\
+	_entry_(13, "dsi", DSI),			\
+	_entry_(14, "dsib", DSIB),			\
+	_entry_(15, "dsic", DSIC),			\
+	_entry_(16, "dsid", DSID),			\
+	_entry_(17, "emmc", SDMMC4),			\
+	_entry_(18, "emmc2", EMMC2),			\
+	_entry_(19, "gpio", GPIO),			\
+	_entry_(20, "hdmi", HDMI),			\
+	_entry_(21, "hsic", HSIC),			\
+	_entry_(22, "lvds", LVDS),			\
+	_entry_(23, "mipi-bias", MIPI_BIAS),	\
+	_entry_(24, "pex-bias", PEX_BIAS),	\
+	_entry_(25, "pex-clk1", PEX_CLK1),	\
+	_entry_(26, "pex-clk2", PEX_CLK2),	\
+	_entry_(27, "pex-ctrl", PEX_CNTRL),	\
+	_entry_(28, "sdmmc1", SDMMC1),		\
+	_entry_(29, "sdmmc3", SDMMC3),		\
+	_entry_(30, "spi", SPI),			\
+	_entry_(31, "spi-hv", SPI_HV),		\
+	_entry_(32, "uart", UART),			\
+	_entry_(33, "usb-bias", USB_BIAS),	\
+	_entry_(34, "usb0", USB0),			\
+	_entry_(35, "usb1", USB1),			\
+	_entry_(36, "usb2", USB2),			\
+	_entry_(37, "usb3", USB3)
+
+#define TEGRA_IO_PAD_INFO(_id, _name, _io_rail_id)			\
+	{								\
+		.name = _name,						\
+		.pins = {(_id)},					\
+		.io_rail_id = TEGRA_IO_RAIL_##_io_rail_id,		\
+	}
+
+static struct tegra_io_pads_cfg_info tegra210_io_pads_cfg_info[] = {
+	TEGRA210_PAD_INFO_TABLE(TEGRA_IO_PAD_INFO),
+};
+
+#define TEGRA_IO_PAD_DESC(_id, _name, _io_rail_id)			\
+	PINCTRL_PIN(_id, _name)
+
+static const struct pinctrl_pin_desc tegra210_io_pads_pinctrl_desc[] = {
+	TEGRA210_PAD_INFO_TABLE(TEGRA_IO_PAD_DESC),
+};
+
+struct tegra_io_pads_info {
+	struct device *dev;
+	struct pinctrl_dev *pctl;
+	struct tegra_io_pads_cfg_info *pads_cfg;
+	unsigned int num_pads_cfg;
+};
+
+static int tegra_iop_pinctrl_get_groups_count(struct pinctrl_dev *pctldev)
+{
+	struct tegra_io_pads_info *tiopi = pinctrl_dev_get_drvdata(pctldev);
+
+	return tiopi->num_pads_cfg;
+}
+
+static const char *tegra_iop_pinctrl_get_group_name(struct pinctrl_dev *pctldev,
+						    unsigned int group)
+{
+	struct tegra_io_pads_info *tiopi = pinctrl_dev_get_drvdata(pctldev);
+
+	return tiopi->pads_cfg[group].name;
+}
+
+static int tegra_iop_pinctrl_get_group_pins(struct pinctrl_dev *pctldev,
+					    unsigned int group,
+					    const unsigned int **pins,
+					    unsigned int *num_pins)
+{
+	struct tegra_io_pads_info *tiopi = pinctrl_dev_get_drvdata(pctldev);
+
+	*pins = tiopi->pads_cfg[group].pins;
+	*num_pins = 1;
+
+	return 0;
+}
+
+static const struct pinctrl_ops tegra_iop_pinctrl_ops = {
+	.get_groups_count = tegra_iop_pinctrl_get_groups_count,
+	.get_group_name = tegra_iop_pinctrl_get_group_name,
+	.get_group_pins = tegra_iop_pinctrl_get_group_pins,
+	.dt_node_to_map = pinconf_generic_dt_node_to_map_pin,
+	.dt_free_map = pinctrl_utils_dt_free_map,
+};
+
+static int tegra_io_pad_pinconf_get(struct pinctrl_dev *pctldev,
+				    unsigned int pin, unsigned long *config)
+{
+	struct tegra_io_pads_info *tiopi = pinctrl_dev_get_drvdata(pctldev);
+	int param = pinconf_to_config_param(*config);
+	struct tegra_io_pads_cfg_info *pad_cfg = &tiopi->pads_cfg[pin];
+	int io_rail_id = pad_cfg->io_rail_id;
+	int arg = 0;
+	int ret;
+
+	switch (param) {
+	case TEGRA_IO_RAIL_VOLTAGE:
+		ret = tegra_io_rail_voltage_get(io_rail_id);
+		if (ret < 0)
+			return ret;
+		arg = ret;
+		break;
+
+	case TEGRA_IO_PAD_DEEP_POWER_DOWN:
+		ret = tegra_io_rail_power_get_status(io_rail_id);
+		if (ret < 0)
+			return ret;
+		arg = !ret;
+		break;
+
+	default:
+		dev_err(tiopi->dev, "The parameter %d not supported\n", param);
+		return -EINVAL;
+	}
+
+	*config = pinconf_to_config_packed(param, (u16)arg);
+	return 0;
+}
+
+static int tegra_io_pad_pinconf_set(struct pinctrl_dev *pctldev,
+				    unsigned int pin, unsigned long *configs,
+				    unsigned int num_configs)
+{
+	struct tegra_io_pads_info *tiopi = pinctrl_dev_get_drvdata(pctldev);
+	struct tegra_io_pads_cfg_info *pad_cfg = &tiopi->pads_cfg[pin];
+	int io_rail_id = pad_cfg->io_rail_id;
+	int param;
+	u16 param_val;
+	int ret;
+	int i;
+
+	for (i = 0; i < num_configs; i++) {
+		param = pinconf_to_config_param(configs[i]);
+		param_val = pinconf_to_config_argument(configs[i]);
+
+		switch (param) {
+		case TEGRA_IO_RAIL_VOLTAGE:
+			ret = tegra_io_rail_voltage_set(io_rail_id, param_val);
+			if (ret < 0) {
+				dev_err(tiopi->dev,
+					"Failed to set voltage %d of pin %u: %d\n",
+					param_val, pin, ret);
+				return ret;
+			}
+			break;
+
+		case TEGRA_IO_PAD_DEEP_POWER_DOWN:
+			if (param_val)
+				ret = tegra_io_rail_power_off(io_rail_id);
+			else
+				ret = tegra_io_rail_power_on(io_rail_id);
+			if (ret < 0) {
+				dev_err(tiopi->dev,
+					"Failed to set DPD %d of pin %u: %d\n",
+					param_val, pin, ret);
+				return ret;
+			}
+			break;
+
+		default:
+			dev_err(tiopi->dev, "The parameter %d not supported\n",
+				param);
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+static const struct pinconf_ops tegra_io_pad_pinconf_ops = {
+	.pin_config_get = tegra_io_pad_pinconf_get,
+	.pin_config_set = tegra_io_pad_pinconf_set,
+};
+
+static struct pinctrl_desc tegra_iop_pinctrl_desc = {
+	.name = "pinctrl-tegra-io-pads",
+	.pctlops = &tegra_iop_pinctrl_ops,
+	.confops = &tegra_io_pad_pinconf_ops,
+	.pins = tegra210_io_pads_pinctrl_desc,
+	.npins = ARRAY_SIZE(tegra210_io_pads_pinctrl_desc),
+	.custom_params = tegra_io_pads_cfg_params,
+	.num_custom_params = ARRAY_SIZE(tegra_io_pads_cfg_params),
+};
+
+static int tegra_iop_pinctrl_probe(struct platform_device *pdev)
+{
+	struct tegra_io_pads_info *tiopi;
+	struct device *dev = &pdev->dev;
+
+	tiopi = devm_kzalloc(&pdev->dev, sizeof(*tiopi), GFP_KERNEL);
+	if (!tiopi)
+		return -ENOMEM;
+
+	tiopi->dev = &pdev->dev;
+	tiopi->dev->of_node = pdev->dev.of_node;
+	tiopi->pads_cfg = tegra210_io_pads_cfg_info;
+	tiopi->num_pads_cfg = ARRAY_SIZE(tegra210_io_pads_cfg_info);
+
+	platform_set_drvdata(pdev, tiopi);
+
+	tiopi->pctl = pinctrl_register(&tegra_iop_pinctrl_desc, dev, tiopi);
+	if (IS_ERR(tiopi->pctl)) {
+		dev_err(&pdev->dev, "Couldn't register pinctrl driver\n");
+		return PTR_ERR(tiopi->pctl);
+	}
+
+	return 0;
+}
+
+static int tegra_iop_pinctrl_remove(struct platform_device *pdev)
+{
+	struct tegra_io_pads_info *tiopi = platform_get_drvdata(pdev);
+
+	pinctrl_unregister(tiopi->pctl);
+
+	return 0;
+}
+
+static const struct of_device_id tegra_io_pads_of_match[] = {
+	{ .compatible = "nvidia,tegra210-io-pad", },
+	{},
+};
+MODULE_DEVICE_TABLE(platform, tegra_iop_pinctrl_devtype);
+
+static struct platform_driver tegra_iop_pinctrl_driver = {
+	.driver = {
+		.name = "pinctrl-tegra-io-pad",
+		.of_match_table = tegra_io_pads_of_match,
+	},
+	.probe = tegra_iop_pinctrl_probe,
+	.remove = tegra_iop_pinctrl_remove,
+};
+
+module_platform_driver(tegra_iop_pinctrl_driver);
+
+MODULE_DESCRIPTION("NVIDIA TEGRA IO pad Control Driver");
+MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
+MODULE_ALIAS("platform:pinctrl-tegra-io-pads");
+MODULE_LICENSE("GPL v2");
-- 
2.1.4