[PATCH 2/2] pinctrl: tegra: Add driver to configure voltage and power of io pads

[Laxman Dewangan <ldewangan@xxxxxxxxxx>]

NVIDIA Tegra124 and later SoCs support the multi-voltage level and
low power state of some of its IO pads. The IO pads can work in
the voltage of the 1.8V and 3.3V of IO power rail sources. When IO
interface are not used then IO pads can be configure in low power
state to reduce the power from that IO pads.

On Tegra124, the IO power rail source is auto detected by SoC and hence
it is only require to configure in low power mode if IO pads are not
used.

On T210 onwards, the auto-detection is removed from SoC and hence SW
must configure the PMC register explicitly to set proper voltage in
IO pads based on IO rail power source voltage.

This driver adds the IO pad driver to configure the power state and
IO pad voltage based on the usage and power tree via pincontrol
framework. The configuration can be static and dynamic.

Signed-off-by: Laxman Dewangan <ldewangan@xxxxxxxxxx>

---
On top of the branch from Thierry's T186 work
	https://github.com/thierryreding/linux/tree/tegra186

 drivers/pinctrl/tegra/Kconfig                |  12 +
 drivers/pinctrl/tegra/Makefile               |   1 +
 drivers/pinctrl/tegra/pinctrl-tegra-io-pad.c | 369 +++++++++++++++++++++++++++
 3 files changed, 382 insertions(+)
 create mode 100644 drivers/pinctrl/tegra/pinctrl-tegra-io-pad.c

diff --git a/drivers/pinctrl/tegra/Kconfig b/drivers/pinctrl/tegra/Kconfig
index 24e20cc..eef1d6b 100644
--- a/drivers/pinctrl/tegra/Kconfig
+++ b/drivers/pinctrl/tegra/Kconfig
@@ -23,6 +23,18 @@ config PINCTRL_TEGRA210
 	bool
 	select PINCTRL_TEGRA
 
+config PINCTRL_TEGRA_IO_PAD
+	bool "Tegra IO pad Control Driver"
+	depends on ARCH_TEGRA
+	select PINCONF
+	select PINMUX
+	help
+	  NVIDIA Tegra124/210 SoC has IO pads which supports multi-voltage
+	  level of interfacing and deep power down mode of IO pads. The
+	  voltage of IO pads are SW configurable based on IO rail of that
+	  pads on T210. 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 d9ea2be..3ebaaa2 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-$(CONFIG_PINCTRL_TEGRA_IO_PAD)	+= pinctrl-tegra-io-pad.o
 obj-$(CONFIG_PINCTRL_TEGRA_XUSB)	+= pinctrl-tegra-xusb.o
diff --git a/drivers/pinctrl/tegra/pinctrl-tegra-io-pad.c b/drivers/pinctrl/tegra/pinctrl-tegra-io-pad.c
new file mode 100644
index 0000000..7af9552
--- /dev/null
+++ b/drivers/pinctrl/tegra/pinctrl-tegra-io-pad.c
@@ -0,0 +1,369 @@
+/*
+ * pinctrl-tegra-io-pad: IO PAD driver for configuration of IO rail and deep
+ *			 Power Down mode via pinctrl framework.
+ *
+ * Copyright (C) 2016 NVIDIA CORPORATION. All rights reserved.
+ *
+ * Author: Laxman Dewangan <ldewangan@xxxxxxxxxx>
+ *
+ * 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_PAD_POWER_SOURCE_VOLTAGE = PIN_CONFIG_END + 1,
+};
+
+static const struct pinconf_generic_params tegra_io_pads_cfg_params[] = {
+	{
+		.property = "nvidia,power-source-voltage",
+		.param = TEGRA_IO_PAD_POWER_SOURCE_VOLTAGE,
+	},
+};
+
+struct tegra_io_pads_cfg_info {
+	const char *name;
+	const unsigned int pins[1];
+	enum tegra_io_pad pad_id;
+	bool voltage_can_change;
+	bool support_low_power_state;
+};
+
+struct tegra_io_pad_soc_data {
+	const struct tegra_io_pads_cfg_info *pads_cfg;
+	int num_pads_cfg;
+	const struct pinctrl_pin_desc *pins_desc;
+	int num_pins_desc;
+};
+
+struct tegra_io_pads_info {
+	struct device *dev;
+	struct pinctrl_dev *pctl;
+	const struct tegra_io_pad_soc_data *soc_data;
+};
+
+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->soc_data->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->soc_data->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->soc_data->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_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);
+	const struct tegra_io_pads_cfg_info *pad_cfg =
+					&tiopi->soc_data->pads_cfg[pin];
+	enum tegra_io_pad pad_id = pad_cfg->pad_id;
+	int arg = 0;
+	int ret;
+
+	switch (param) {
+	case TEGRA_IO_PAD_POWER_SOURCE_VOLTAGE:
+		ret = tegra_io_pad_get_voltage(pad_id);
+		if (ret < 0)
+			return ret;
+		arg = ret;
+		break;
+
+	case PIN_CONFIG_LOW_POWER_MODE:
+		ret = tegra_io_pad_power_get_status(pad_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);
+	const struct tegra_io_pads_cfg_info *pad_cfg =
+					&tiopi->soc_data->pads_cfg[pin];
+	int pad_id = pad_cfg->pad_id;
+	u16 param_val;
+	int param;
+	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_PAD_POWER_SOURCE_VOLTAGE:
+			ret = tegra_io_pad_set_voltage(pad_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 PIN_CONFIG_LOW_POWER_MODE:
+			if (param_val)
+				ret = tegra_io_pad_power_disable(pad_id);
+			else
+				ret = tegra_io_pad_power_enable(pad_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,
+	.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 device *dev = &pdev->dev;
+	const struct platform_device_id *id = platform_get_device_id(pdev);
+	struct device_node *np_parent = pdev->dev.parent->of_node;
+	struct tegra_io_pads_info *tiopi;
+
+	if (!np_parent) {
+		dev_err(&pdev->dev, "PMC should be register from DT\n");
+		return -ENODEV;
+	}
+
+	tiopi = devm_kzalloc(&pdev->dev, sizeof(*tiopi), GFP_KERNEL);
+	if (!tiopi)
+		return -ENOMEM;
+
+	tiopi->dev = &pdev->dev;
+	pdev->dev.of_node = np_parent;
+	tiopi->soc_data = (const struct tegra_io_pad_soc_data *)id->driver_data;
+	tegra_iop_pinctrl_desc.pins = tiopi->soc_data->pins_desc;
+	tegra_iop_pinctrl_desc.npins = tiopi->soc_data->num_pins_desc;
+	platform_set_drvdata(pdev, tiopi);
+
+	tiopi->pctl = devm_pinctrl_register(dev, &tegra_iop_pinctrl_desc,
+					    tiopi);
+	if (IS_ERR(tiopi->pctl)) {
+		int ret = PTR_ERR(tiopi->pctl);
+
+		dev_err(dev, "Failed to register io-pad pinctrl driver: %d\n",
+			ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+#define TEGRA124_PAD_INFO_TABLE(_entry_)			\
+	_entry_(0, "audio", AUDIO, true, false),		\
+	_entry_(1, "bb", BB, true, false),			\
+	_entry_(2, "cam", CAM, true, false),			\
+	_entry_(3, "comp", COMP, true, false),			\
+	_entry_(4, "csia", CSIA, true, false),			\
+	_entry_(5, "csib", CSIB, true, false),			\
+	_entry_(6, "csie", CSIE, true, false),			\
+	_entry_(7, "dsi", DSI, true, false),			\
+	_entry_(8, "dsib", DSIB, true, false),			\
+	_entry_(9, "dsic", DSIC, true, false),			\
+	_entry_(10, "dsid", DSID, true, false),			\
+	_entry_(11, "hdmi", HDMI, true, false),			\
+	_entry_(12, "hsic", HSIC, true, false),			\
+	_entry_(13, "hv", HV, true, false),			\
+	_entry_(14, "lvds", LVDS, true, false),			\
+	_entry_(15, "mipi-bias", MIPI_BIAS, true, false),	\
+	_entry_(16, "nand", NAND, true, false),			\
+	_entry_(17, "pex-bias", PEX_BIAS, true, false),		\
+	_entry_(18, "pex-clk1", PEX_CLK1, true, false),		\
+	_entry_(19, "pex-clk2", PEX_CLK2, true, false),		\
+	_entry_(20, "pex-ctrl", PEX_CNTRL, true, false),	\
+	_entry_(21, "sdmmc1", SDMMC1, true, false),		\
+	_entry_(22, "sdmmc3", SDMMC3, true, false),		\
+	_entry_(23, "sdmmc4", SDMMC4, true, false),		\
+	_entry_(24, "sys-ddc", SYS_DDC, true, false),		\
+	_entry_(25, "uart", UART, true, false),			\
+	_entry_(26, "usb0", USB0, true, false),			\
+	_entry_(27, "usb1", USB1, true, false),			\
+	_entry_(28, "usb2", USB2, true, false),			\
+	_entry_(29, "usb-bias", USB_BIAS, true, false)
+
+#define TEGRA210_PAD_INFO_TABLE(_entry_)			\
+	_entry_(0, "audio", AUDIO, true, true),			\
+	_entry_(1, "audio-hv", AUDIO_HV, true, true),		\
+	_entry_(2, "cam", CAM, true, true),			\
+	_entry_(3, "csia", CSIA, true, false),			\
+	_entry_(4, "csib", CSIB, true, false),			\
+	_entry_(5, "csic", CSIC, true, false),			\
+	_entry_(6, "csid", CSID, true, false),			\
+	_entry_(7, "csie", CSIE, true, false),			\
+	_entry_(8, "csif", CSIF, true, false),			\
+	_entry_(9, "dbg", DBG, true, true),			\
+	_entry_(10, "debug-nonao", DEBUG_NONAO, true, false),	\
+	_entry_(11, "dmic", DMIC, true, true),			\
+	_entry_(12, "dp", DP, true, false),			\
+	_entry_(13, "dsi", DSI, true, false),			\
+	_entry_(14, "dsib", DSIB, true, false),			\
+	_entry_(15, "dsic", DSIC, true, false),			\
+	_entry_(16, "dsid", DSID, true, false),			\
+	_entry_(17, "emmc", SDMMC4, true, false),		\
+	_entry_(18, "emmc2", EMMC2, true, false),		\
+	_entry_(19, "gpio", GPIO, true, true),			\
+	_entry_(20, "hdmi", HDMI, true, false),			\
+	_entry_(21, "hsic", HSIC, true, false),			\
+	_entry_(22, "lvds", LVDS, true, false),			\
+	_entry_(23, "mipi-bias", MIPI_BIAS, true, false),	\
+	_entry_(24, "pex-bias", PEX_BIAS, true, false),		\
+	_entry_(25, "pex-clk1", PEX_CLK1, true, false),		\
+	_entry_(26, "pex-clk2", PEX_CLK2, true, false),		\
+	_entry_(27, "pex-ctrl", PEX_CNTRL, false, true),	\
+	_entry_(28, "sdmmc1", SDMMC1, true, true),		\
+	_entry_(29, "sdmmc3", SDMMC3, true, true),		\
+	_entry_(30, "spi", SPI, true, true),			\
+	_entry_(31, "spi-hv", SPI_HV, true, true),		\
+	_entry_(32, "uart", UART, true, true),			\
+	_entry_(33, "usb0", USB0, true, false),			\
+	_entry_(34, "usb1", USB1, true, false),			\
+	_entry_(35, "usb2", USB2, true, false),			\
+	_entry_(36, "usb3", USB3, true, false),			\
+	_entry_(37, "usb-bias", USB_BIAS, true, false)
+
+#define TEGRA_IO_PAD_INFO(_id, _name, _pad_id, _lpstate, _vchange)	\
+	{								\
+		.name = _name,						\
+		.pins = {(_id)},					\
+		.pad_id = TEGRA_IO_PAD_##_pad_id,			\
+		.voltage_can_change = (_vchange),			\
+		.support_low_power_state = (_lpstate),			\
+	}
+
+static const struct tegra_io_pads_cfg_info tegra124_io_pads_cfg_info[] = {
+	TEGRA124_PAD_INFO_TABLE(TEGRA_IO_PAD_INFO),
+};
+
+static const 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, _pad_id,  _vchange, _lpstate)	\
+	PINCTRL_PIN(_id, _name)
+
+static const struct pinctrl_pin_desc tegra124_io_pads_pinctrl_desc[] = {
+	TEGRA124_PAD_INFO_TABLE(TEGRA_IO_PAD_DESC),
+};
+
+static const struct pinctrl_pin_desc tegra210_io_pads_pinctrl_desc[] = {
+	TEGRA210_PAD_INFO_TABLE(TEGRA_IO_PAD_DESC),
+};
+
+static const struct tegra_io_pad_soc_data tegra124_io_pad_soc_data = {
+	.pins_desc	= tegra124_io_pads_pinctrl_desc,
+	.num_pins_desc	= ARRAY_SIZE(tegra124_io_pads_pinctrl_desc),
+	.pads_cfg	= tegra124_io_pads_cfg_info,
+	.num_pins_desc	= ARRAY_SIZE(tegra124_io_pads_cfg_info),
+};
+
+static const struct tegra_io_pad_soc_data tegra210_io_pad_soc_data = {
+	.pins_desc	= tegra210_io_pads_pinctrl_desc,
+	.num_pins_desc	= ARRAY_SIZE(tegra210_io_pads_pinctrl_desc),
+	.pads_cfg	= tegra210_io_pads_cfg_info,
+	.num_pins_desc	= ARRAY_SIZE(tegra210_io_pads_cfg_info),
+};
+
+static const struct platform_device_id tegra_io_pads_dev_id[] = {
+	{
+		.name = "pinctrl-t124-io-pad",
+		.driver_data = (kernel_ulong_t)&tegra124_io_pad_soc_data,
+	}, {
+		.name = "pinctrl-t210-io-pad",
+		.driver_data = (kernel_ulong_t)&tegra210_io_pad_soc_data,
+	}, {
+	},
+};
+MODULE_DEVICE_TABLE(platform, tegra_io_pads_dev_id);
+
+static struct platform_driver tegra_iop_pinctrl_driver = {
+	.driver		= {
+		.name	= "pinctrl-tegra-io-pad",
+	},
+	.probe		= tegra_iop_pinctrl_probe,
+	.id_table	= tegra_io_pads_dev_id,
+};
+
+module_platform_driver(tegra_iop_pinctrl_driver);
+
+MODULE_DESCRIPTION("NVIDIA TEGRA IO pad Control Driver");
+MODULE_AUTHOR("Laxman Dewangan <ldewangan@xxxxxxxxxx>");
+MODULE_LICENSE("GPL v2");
-- 
2.1.4

--
To unsubscribe from this list: send the line "unsubscribe linux-gpio" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html