[mirror_ubuntu-bionic-kernel.git] / drivers / staging / greybus / arche-apb-ctrl.c

/*
 * Arche Platform driver to control APB.
 *
 * Copyright 2014-2015 Google Inc.
 * Copyright 2014-2015 Linaro Ltd.
 *
 * Released under the GPLv2 only.
 */

#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/gpio.h>
#include <linux/interrupt.h>
#include <linux/of_gpio.h>
#include <linux/of_irq.h>
#include <linux/module.h>
#include <linux/pinctrl/consumer.h>
#include <linux/platform_device.h>
#include <linux/pm.h>
#include <linux/regulator/consumer.h>
#include <linux/spinlock.h>
#include "arche_platform.h"


static void apb_bootret_deassert(struct device *dev);

struct arche_apb_ctrl_drvdata {
	/* Control GPIO signals to and from AP <=> AP Bridges */
	int resetn_gpio;
	int boot_ret_gpio;
	int pwroff_gpio;
	int wake_in_gpio;
	int wake_out_gpio;
	int pwrdn_gpio;

	enum arche_platform_state state;
	bool init_disabled;

	struct regulator *vcore;
	struct regulator *vio;

	int clk_en_gpio;
	struct clk *clk;

	struct pinctrl *pinctrl;
	struct pinctrl_state *pin_default;

	/* V2: SPI Bus control  */
	int spi_en_gpio;
	bool spi_en_polarity_high;
};

/*
 * Note that these low level api's are active high
 */
static inline void deassert_reset(unsigned int gpio)
{
	gpio_set_value(gpio, 1);
}

static inline void assert_reset(unsigned int gpio)
{
	gpio_set_value(gpio, 0);
}

/*
 * Note: Please do not modify the below sequence, as it is as per the spec
 */
static int coldboot_seq(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct arche_apb_ctrl_drvdata *apb = platform_get_drvdata(pdev);
	int ret;

	if (apb->init_disabled ||
			apb->state == ARCHE_PLATFORM_STATE_ACTIVE)
		return 0;

	/* Hold APB in reset state */
	assert_reset(apb->resetn_gpio);

	if (apb->state == ARCHE_PLATFORM_STATE_FW_FLASHING &&
			gpio_is_valid(apb->spi_en_gpio))
		devm_gpio_free(dev, apb->spi_en_gpio);

	/* Enable power to APB */
	if (!IS_ERR(apb->vcore)) {
		ret = regulator_enable(apb->vcore);
		if (ret) {
			dev_err(dev, "failed to enable core regulator\n");
			return ret;
		}
	}

	if (!IS_ERR(apb->vio)) {
		ret = regulator_enable(apb->vio);
		if (ret) {
			dev_err(dev, "failed to enable IO regulator\n");
			return ret;
		}
	}

	apb_bootret_deassert(dev);

	/* On DB3 clock was not mandatory */
	if (gpio_is_valid(apb->clk_en_gpio))
		gpio_set_value(apb->clk_en_gpio, 1);

	usleep_range(100, 200);

	/* deassert reset to APB : Active-low signal */
	deassert_reset(apb->resetn_gpio);

	apb->state = ARCHE_PLATFORM_STATE_ACTIVE;

	return 0;
}

static int fw_flashing_seq(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct arche_apb_ctrl_drvdata *apb = platform_get_drvdata(pdev);
	int ret;

	if (apb->init_disabled ||
			apb->state == ARCHE_PLATFORM_STATE_FW_FLASHING)
		return 0;

	ret = regulator_enable(apb->vcore);
	if (ret) {
		dev_err(dev, "failed to enable core regulator\n");
		return ret;
	}

	ret = regulator_enable(apb->vio);
	if (ret) {
		dev_err(dev, "failed to enable IO regulator\n");
		return ret;
	}

	if (gpio_is_valid(apb->spi_en_gpio)) {
		unsigned long flags;

		if (apb->spi_en_polarity_high)
			flags = GPIOF_OUT_INIT_HIGH;
		else
			flags = GPIOF_OUT_INIT_LOW;

		ret = devm_gpio_request_one(dev, apb->spi_en_gpio,
				flags, "apb_spi_en");
		if (ret) {
			dev_err(dev, "Failed requesting SPI bus en gpio %d\n",
				apb->spi_en_gpio);
			return ret;
		}
	}

	/* for flashing device should be in reset state */
	assert_reset(apb->resetn_gpio);
	apb->state = ARCHE_PLATFORM_STATE_FW_FLASHING;

	return 0;
}

static int standby_boot_seq(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct arche_apb_ctrl_drvdata *apb = platform_get_drvdata(pdev);

	if (apb->init_disabled)
		return 0;

	/*
	 * Even if it is in OFF state,
	 * then we do not want to change the state
	 */
	if (apb->state == ARCHE_PLATFORM_STATE_STANDBY ||
			apb->state == ARCHE_PLATFORM_STATE_OFF)
		return 0;

	if (apb->state == ARCHE_PLATFORM_STATE_FW_FLASHING &&
			gpio_is_valid(apb->spi_en_gpio))
		devm_gpio_free(dev, apb->spi_en_gpio);

	/*
	 * As per WDM spec, do nothing
	 *
	 * Pasted from WDM spec,
	 *  - A falling edge on POWEROFF_L is detected (a)
	 *  - WDM enters standby mode, but no output signals are changed
	 */

	/* TODO: POWEROFF_L is input to WDM module  */
	apb->state = ARCHE_PLATFORM_STATE_STANDBY;
	return 0;
}

static void poweroff_seq(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct arche_apb_ctrl_drvdata *apb = platform_get_drvdata(pdev);

	if (apb->init_disabled || apb->state == ARCHE_PLATFORM_STATE_OFF)
		return;

	if (apb->state == ARCHE_PLATFORM_STATE_FW_FLASHING &&
			gpio_is_valid(apb->spi_en_gpio))
		devm_gpio_free(dev, apb->spi_en_gpio);

	/* disable the clock */
	if (gpio_is_valid(apb->clk_en_gpio))
		gpio_set_value(apb->clk_en_gpio, 0);

	if (!IS_ERR(apb->vcore) && regulator_is_enabled(apb->vcore) > 0)
		regulator_disable(apb->vcore);

	if (!IS_ERR(apb->vio) && regulator_is_enabled(apb->vio) > 0)
		regulator_disable(apb->vio);

	/* As part of exit, put APB back in reset state */
	assert_reset(apb->resetn_gpio);
	apb->state = ARCHE_PLATFORM_STATE_OFF;

	/* TODO: May have to send an event to SVC about this exit */
}

static void apb_bootret_deassert(struct device *dev)
{
	struct arche_apb_ctrl_drvdata *apb = dev_get_drvdata(dev);

	gpio_set_value(apb->boot_ret_gpio, 0);
}

int apb_ctrl_coldboot(struct device *dev)
{
	return coldboot_seq(to_platform_device(dev));
}

int apb_ctrl_fw_flashing(struct device *dev)
{
	return fw_flashing_seq(to_platform_device(dev));
}

int apb_ctrl_standby_boot(struct device *dev)
{
	return standby_boot_seq(to_platform_device(dev));
}

void apb_ctrl_poweroff(struct device *dev)
{
	poweroff_seq(to_platform_device(dev));
}

static ssize_t state_store(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t count)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct arche_apb_ctrl_drvdata *apb = platform_get_drvdata(pdev);
	int ret = 0;
	bool is_disabled;

	if (sysfs_streq(buf, "off")) {
		if (apb->state == ARCHE_PLATFORM_STATE_OFF)
			return count;

		poweroff_seq(pdev);
	} else if (sysfs_streq(buf, "active")) {
		if (apb->state == ARCHE_PLATFORM_STATE_ACTIVE)
			return count;

		poweroff_seq(pdev);
		is_disabled = apb->init_disabled;
		apb->init_disabled = false;
		ret = coldboot_seq(pdev);
		if (ret)
			apb->init_disabled = is_disabled;
	} else if (sysfs_streq(buf, "standby")) {
		if (apb->state == ARCHE_PLATFORM_STATE_STANDBY)
			return count;

		ret = standby_boot_seq(pdev);
	} else if (sysfs_streq(buf, "fw_flashing")) {
		if (apb->state == ARCHE_PLATFORM_STATE_FW_FLASHING)
			return count;

		/*
		 * First we want to make sure we power off everything
		 * and then enter FW flashing state
		 */
		poweroff_seq(pdev);
		ret = fw_flashing_seq(pdev);
	} else {
		dev_err(dev, "unknown state\n");
		ret = -EINVAL;
	}

	return ret ? ret : count;
}

static ssize_t state_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct arche_apb_ctrl_drvdata *apb = dev_get_drvdata(dev);

	switch (apb->state) {
	case ARCHE_PLATFORM_STATE_OFF:
		return sprintf(buf, "off%s\n",
				apb->init_disabled ? ",disabled" : "");
	case ARCHE_PLATFORM_STATE_ACTIVE:
		return sprintf(buf, "active\n");
	case ARCHE_PLATFORM_STATE_STANDBY:
		return sprintf(buf, "standby\n");
	case ARCHE_PLATFORM_STATE_FW_FLASHING:
		return sprintf(buf, "fw_flashing\n");
	default:
		return sprintf(buf, "unknown state\n");
	}
}

static DEVICE_ATTR_RW(state);

static int apb_ctrl_get_devtree_data(struct platform_device *pdev,
		struct arche_apb_ctrl_drvdata *apb)
{
	struct device *dev = &pdev->dev;
	struct device_node *np = dev->of_node;
	int ret;

	apb->resetn_gpio = of_get_named_gpio(np, "reset-gpios", 0);
	if (apb->resetn_gpio < 0) {
		dev_err(dev, "failed to get reset gpio\n");
		return apb->resetn_gpio;
	}
	ret = devm_gpio_request_one(dev, apb->resetn_gpio,
			GPIOF_OUT_INIT_LOW, "apb-reset");
	if (ret) {
		dev_err(dev, "Failed requesting reset gpio %d\n",
				apb->resetn_gpio);
		return ret;
	}

	apb->boot_ret_gpio = of_get_named_gpio(np, "boot-ret-gpios", 0);
	if (apb->boot_ret_gpio < 0) {
		dev_err(dev, "failed to get boot retention gpio\n");
		return apb->boot_ret_gpio;
	}
	ret = devm_gpio_request_one(dev, apb->boot_ret_gpio,
			GPIOF_OUT_INIT_LOW, "boot retention");
	if (ret) {
		dev_err(dev, "Failed requesting bootret gpio %d\n",
				apb->boot_ret_gpio);
		return ret;
	}

	/* It's not mandatory to support power management interface */
	apb->pwroff_gpio = of_get_named_gpio(np, "pwr-off-gpios", 0);
	if (apb->pwroff_gpio < 0) {
		dev_err(dev, "failed to get power off gpio\n");
		return apb->pwroff_gpio;
	}
	ret = devm_gpio_request_one(dev, apb->pwroff_gpio,
			GPIOF_IN, "pwroff_n");
	if (ret) {
		dev_err(dev, "Failed requesting pwroff_n gpio %d\n",
				apb->pwroff_gpio);
		return ret;
	}

	/* Do not make clock mandatory as of now (for DB3) */
	apb->clk_en_gpio = of_get_named_gpio(np, "clock-en-gpio", 0);
	if (apb->clk_en_gpio < 0) {
		dev_warn(dev, "failed to get clock en gpio\n");
	} else if (gpio_is_valid(apb->clk_en_gpio)) {
		ret = devm_gpio_request_one(dev, apb->clk_en_gpio,
				GPIOF_OUT_INIT_LOW, "apb_clk_en");
		if (ret) {
			dev_warn(dev, "Failed requesting APB clock en gpio %d\n",
					apb->clk_en_gpio);
			return ret;
		}
	}

	apb->pwrdn_gpio = of_get_named_gpio(np, "pwr-down-gpios", 0);
	if (apb->pwrdn_gpio < 0)
		dev_warn(dev, "failed to get power down gpio\n");

	/* Regulators are optional, as we may have fixed supply coming in */
	apb->vcore = devm_regulator_get(dev, "vcore");
	if (IS_ERR(apb->vcore))
		dev_warn(dev, "no core regulator found\n");

	apb->vio = devm_regulator_get(dev, "vio");
	if (IS_ERR(apb->vio))
		dev_warn(dev, "no IO regulator found\n");

	apb->pinctrl = devm_pinctrl_get(&pdev->dev);
	if (IS_ERR(apb->pinctrl)) {
		dev_err(&pdev->dev, "could not get pinctrl handle\n");
		return PTR_ERR(apb->pinctrl);
	}
	apb->pin_default = pinctrl_lookup_state(apb->pinctrl, "default");
	if (IS_ERR(apb->pin_default)) {
		dev_err(&pdev->dev, "could not get default pin state\n");
		return PTR_ERR(apb->pin_default);
	}

	/* Only applicable for platform >= V2 */
	apb->spi_en_gpio = of_get_named_gpio(np, "spi-en-gpio", 0);
	if (apb->spi_en_gpio >= 0) {
		if (of_property_read_bool(pdev->dev.of_node,
					"spi-en-active-high"))
			apb->spi_en_polarity_high = true;
	}

	return 0;
}

static int arche_apb_ctrl_probe(struct platform_device *pdev)
{
	int ret;
	struct arche_apb_ctrl_drvdata *apb;
	struct device *dev = &pdev->dev;

	apb = devm_kzalloc(&pdev->dev, sizeof(*apb), GFP_KERNEL);
	if (!apb)
		return -ENOMEM;

	ret = apb_ctrl_get_devtree_data(pdev, apb);
	if (ret) {
		dev_err(dev, "failed to get apb devicetree data %d\n", ret);
		return ret;
	}

	/* Initially set APB to OFF state */
	apb->state = ARCHE_PLATFORM_STATE_OFF;
	/* Check whether device needs to be enabled on boot */
	if (of_property_read_bool(pdev->dev.of_node, "arche,init-disable"))
		apb->init_disabled = true;

	platform_set_drvdata(pdev, apb);

	/* Create sysfs interface to allow user to change state dynamically */
	ret = device_create_file(dev, &dev_attr_state);
	if (ret) {
		dev_err(dev, "failed to create state file in sysfs\n");
		return ret;
	}

	dev_info(&pdev->dev, "Device registered successfully\n");
	return 0;
}

static int arche_apb_ctrl_remove(struct platform_device *pdev)
{
	device_remove_file(&pdev->dev, &dev_attr_state);
	poweroff_seq(pdev);
	platform_set_drvdata(pdev, NULL);

	return 0;
}

static int __maybe_unused arche_apb_ctrl_suspend(struct device *dev)
{
	/*
	 * If timing profile permits, we may shutdown bridge
	 * completely
	 *
	 * TODO: sequence ??
	 *
	 * Also, need to make sure we meet precondition for unipro suspend
	 * Precondition: Definition ???
	 */
	return 0;
}

static int __maybe_unused arche_apb_ctrl_resume(struct device *dev)
{
	/*
	 * Atleast for ES2 we have to meet the delay requirement between
	 * unipro switch and AP bridge init, depending on whether bridge is in
	 * OFF state or standby state.
	 *
	 * Based on whether bridge is in standby or OFF state we may have to
	 * assert multiple signals. Please refer to WDM spec, for more info.
	 *
	 */
	return 0;
}

static void arche_apb_ctrl_shutdown(struct platform_device *pdev)
{
	apb_ctrl_poweroff(&pdev->dev);
}

static SIMPLE_DEV_PM_OPS(arche_apb_ctrl_pm_ops, arche_apb_ctrl_suspend,
			 arche_apb_ctrl_resume);

static const struct of_device_id arche_apb_ctrl_of_match[] = {
	{ .compatible = "usbffff,2", },
	{ },
};

static struct platform_driver arche_apb_ctrl_device_driver = {
	.probe		= arche_apb_ctrl_probe,
	.remove		= arche_apb_ctrl_remove,
	.shutdown	= arche_apb_ctrl_shutdown,
	.driver		= {
		.name	= "arche-apb-ctrl",
		.pm	= &arche_apb_ctrl_pm_ops,
		.of_match_table = arche_apb_ctrl_of_match,
	}
};

int __init arche_apb_init(void)
{
	return platform_driver_register(&arche_apb_ctrl_device_driver);
}

void __exit arche_apb_exit(void)
{
	platform_driver_unregister(&arche_apb_ctrl_device_driver);
}
Commit	Line	Data
5a781787 VH	1	/*
	2	* Arche Platform driver to control APB.
	3	*
	4	* Copyright 2014-2015 Google Inc.
	5	* Copyright 2014-2015 Linaro Ltd.
	6	*
	7	* Released under the GPLv2 only.
	8	*/
	9
3b858df0	10	#include <linux/clk.h>
5a781787	11	#include <linux/delay.h>
5a781787	12	#include <linux/gpio.h>
3b858df0	13	#include <linux/interrupt.h>
5a781787 VH	14	#include <linux/of_gpio.h>
5a781787 VH	15	#include <linux/of_irq.h>
3b858df0	16	#include <linux/module.h>
5a781787	17	#include <linux/pinctrl/consumer.h>
3b858df0 VK	18	#include <linux/platform_device.h>
	19	#include <linux/pm.h>
	20	#include <linux/regulator/consumer.h>
	21	#include <linux/spinlock.h>
1e5dd1f8	22	#include "arche_platform.h"
5a781787	23
5a781787	24
1e029b83 JH	25	static void apb_bootret_deassert(struct device *dev);
1e029b83 JH	26
5a781787 VH	27	struct arche_apb_ctrl_drvdata {
5a781787 VH	28	/* Control GPIO signals to and from AP <=> AP Bridges */
5a781787 VH	29	int resetn_gpio;
	30	int boot_ret_gpio;
	31	int pwroff_gpio;
	32	int wake_in_gpio;
	33	int wake_out_gpio;
	34	int pwrdn_gpio;
	35
a821adb4	36	enum arche_platform_state state;
af3aae10	37	bool init_disabled;
5a781787 VH	38
	39	struct regulator *vcore;
	40	struct regulator *vio;
	41
7fe93014	42	int clk_en_gpio;
5a781787 VH	43	struct clk *clk;
	44
	45	struct pinctrl *pinctrl;
	46	struct pinctrl_state *pin_default;
921dbe52 VH	47
	48	/* V2: SPI Bus control */
	49	int spi_en_gpio;
	50	bool spi_en_polarity_high;
5a781787 VH	51	};
	52
	53	/*
	54	* Note that these low level api's are active high
	55	*/
f1e9cbd5	56	static inline void deassert_reset(unsigned int gpio)
5a781787 VH	57	{
5a781787 VH	58	gpio_set_value(gpio, 1);
5a781787 VH	59	}
5a781787 VH	60
f1e9cbd5	61	static inline void assert_reset(unsigned int gpio)
5a781787 VH	62	{
	63	gpio_set_value(gpio, 0);
	64	}
	65
5a781787 VH	66	/*
	67	* Note: Please do not modify the below sequence, as it is as per the spec
	68	*/
80a057aa	69	static int coldboot_seq(struct platform_device *pdev)
5a781787 VH	70	{
5a781787 VH	71	struct device *dev = &pdev->dev;
6961e046	72	struct arche_apb_ctrl_drvdata *apb = platform_get_drvdata(pdev);
5a781787 VH	73	int ret;
5a781787 VH	74
c5e7cbaf VH	75	if (apb->init_disabled \|\|
c5e7cbaf VH	76	apb->state == ARCHE_PLATFORM_STATE_ACTIVE)
af3aae10 VH	77	return 0;
af3aae10 VH	78
5a781787	79	/* Hold APB in reset state */
6ceed512	80	assert_reset(apb->resetn_gpio);
5a781787	81
921dbe52 VH	82	if (apb->state == ARCHE_PLATFORM_STATE_FW_FLASHING &&
	83	gpio_is_valid(apb->spi_en_gpio))
	84	devm_gpio_free(dev, apb->spi_en_gpio);
	85
5a781787	86	/* Enable power to APB */
dcf77c39	87	if (!IS_ERR(apb->vcore)) {
5a781787 VH	88	ret = regulator_enable(apb->vcore);
	89	if (ret) {
	90	dev_err(dev, "failed to enable core regulator\n");
	91	return ret;
	92	}
	93	}
aa187d33	94
dcf77c39	95	if (!IS_ERR(apb->vio)) {
5a781787 VH	96	ret = regulator_enable(apb->vio);
	97	if (ret) {
	98	dev_err(dev, "failed to enable IO regulator\n");
6ceed512	99	return ret;
5a781787 VH	100	}
	101	}
	102
970dc85b	103	apb_bootret_deassert(dev);
aa187d33 VH	104
aa187d33 VH	105	/* On DB3 clock was not mandatory */
6ceed512 VH	106	if (gpio_is_valid(apb->clk_en_gpio))
6ceed512 VH	107	gpio_set_value(apb->clk_en_gpio, 1);
aa187d33 VH	108
aa187d33 VH	109	usleep_range(100, 200);
5a781787	110
6ceed512 VH	111	/* deassert reset to APB : Active-low signal */
6ceed512 VH	112	deassert_reset(apb->resetn_gpio);
d258432f	113
6ceed512	114	apb->state = ARCHE_PLATFORM_STATE_ACTIVE;
5a781787	115
6ceed512	116	return 0;
5a781787 VH	117	}
5a781787 VH	118
80a057aa	119	static int fw_flashing_seq(struct platform_device *pdev)
33d76291 VH	120	{
	121	struct device *dev = &pdev->dev;
	122	struct arche_apb_ctrl_drvdata *apb = platform_get_drvdata(pdev);
	123	int ret;
	124
c5e7cbaf VH	125	if (apb->init_disabled \|\|
c5e7cbaf VH	126	apb->state == ARCHE_PLATFORM_STATE_FW_FLASHING)
af3aae10 VH	127	return 0;
af3aae10 VH	128
33d76291 VH	129	ret = regulator_enable(apb->vcore);
	130	if (ret) {
	131	dev_err(dev, "failed to enable core regulator\n");
	132	return ret;
	133	}
	134
	135	ret = regulator_enable(apb->vio);
	136	if (ret) {
	137	dev_err(dev, "failed to enable IO regulator\n");
	138	return ret;
	139	}
	140
921dbe52 VH	141	if (gpio_is_valid(apb->spi_en_gpio)) {
	142	unsigned long flags;
	143
	144	if (apb->spi_en_polarity_high)
	145	flags = GPIOF_OUT_INIT_HIGH;
	146	else
	147	flags = GPIOF_OUT_INIT_LOW;
	148
	149	ret = devm_gpio_request_one(dev, apb->spi_en_gpio,
	150	flags, "apb_spi_en");
	151	if (ret) {
	152	dev_err(dev, "Failed requesting SPI bus en gpio %d\n",
	153	apb->spi_en_gpio);
	154	return ret;
	155	}
	156	}
	157
33d76291 VH	158	/* for flashing device should be in reset state */
	159	assert_reset(apb->resetn_gpio);
	160	apb->state = ARCHE_PLATFORM_STATE_FW_FLASHING;
	161
	162	return 0;
	163	}
	164
80a057aa	165	static int standby_boot_seq(struct platform_device *pdev)
33d76291	166	{
921dbe52	167	struct device *dev = &pdev->dev;
33d76291 VH	168	struct arche_apb_ctrl_drvdata *apb = platform_get_drvdata(pdev);
33d76291 VH	169
af3aae10 VH	170	if (apb->init_disabled)
	171	return 0;
	172
461ab807 GK	173	/*
	174	* Even if it is in OFF state,
	175	* then we do not want to change the state
	176	*/
c5e7cbaf VH	177	if (apb->state == ARCHE_PLATFORM_STATE_STANDBY \|\|
c5e7cbaf VH	178	apb->state == ARCHE_PLATFORM_STATE_OFF)
33d76291 VH	179	return 0;
33d76291 VH	180
921dbe52 VH	181	if (apb->state == ARCHE_PLATFORM_STATE_FW_FLASHING &&
	182	gpio_is_valid(apb->spi_en_gpio))
	183	devm_gpio_free(dev, apb->spi_en_gpio);
	184
33d76291 VH	185	/*
	186	* As per WDM spec, do nothing
	187	*
	188	* Pasted from WDM spec,
	189	* - A falling edge on POWEROFF_L is detected (a)
	190	* - WDM enters standby mode, but no output signals are changed
1047cc13	191	*/
33d76291 VH	192
	193	/* TODO: POWEROFF_L is input to WDM module */
	194	apb->state = ARCHE_PLATFORM_STATE_STANDBY;
	195	return 0;
	196	}
	197
80a057aa	198	static void poweroff_seq(struct platform_device *pdev)
5667ab17	199	{
921dbe52	200	struct device *dev = &pdev->dev;
6961e046 VH	201	struct arche_apb_ctrl_drvdata *apb = platform_get_drvdata(pdev);
6961e046 VH	202
c5e7cbaf	203	if (apb->init_disabled \|\| apb->state == ARCHE_PLATFORM_STATE_OFF)
af3aae10 VH	204	return;
af3aae10 VH	205
921dbe52 VH	206	if (apb->state == ARCHE_PLATFORM_STATE_FW_FLASHING &&
	207	gpio_is_valid(apb->spi_en_gpio))
	208	devm_gpio_free(dev, apb->spi_en_gpio);
	209
5667ab17 VH	210	/* disable the clock */
	211	if (gpio_is_valid(apb->clk_en_gpio))
	212	gpio_set_value(apb->clk_en_gpio, 0);
	213
	214	if (!IS_ERR(apb->vcore) && regulator_is_enabled(apb->vcore) > 0)
	215	regulator_disable(apb->vcore);
	216
	217	if (!IS_ERR(apb->vio) && regulator_is_enabled(apb->vio) > 0)
	218	regulator_disable(apb->vio);
	219
	220	/* As part of exit, put APB back in reset state */
	221	assert_reset(apb->resetn_gpio);
	222	apb->state = ARCHE_PLATFORM_STATE_OFF;
	223
	224	/* TODO: May have to send an event to SVC about this exit */
	225	}
	226
1e029b83	227	static void apb_bootret_deassert(struct device *dev)
970dc85b BD	228	{
	229	struct arche_apb_ctrl_drvdata *apb = dev_get_drvdata(dev);
	230
	231	gpio_set_value(apb->boot_ret_gpio, 0);
	232	}
	233
65fd5a50 VH	234	int apb_ctrl_coldboot(struct device *dev)
	235	{
	236	return coldboot_seq(to_platform_device(dev));
	237	}
	238
	239	int apb_ctrl_fw_flashing(struct device *dev)
	240	{
	241	return fw_flashing_seq(to_platform_device(dev));
	242	}
	243
	244	int apb_ctrl_standby_boot(struct device *dev)
	245	{
	246	return standby_boot_seq(to_platform_device(dev));
	247	}
	248
	249	void apb_ctrl_poweroff(struct device *dev)
	250	{
	251	poweroff_seq(to_platform_device(dev));
	252	}
	253
33d76291 VH	254	static ssize_t state_store(struct device *dev,
	255	struct device_attribute attr, const char buf, size_t count)
	256	{
	257	struct platform_device *pdev = to_platform_device(dev);
	258	struct arche_apb_ctrl_drvdata *apb = platform_get_drvdata(pdev);
	259	int ret = 0;
af3aae10	260	bool is_disabled;
33d76291 VH	261
	262	if (sysfs_streq(buf, "off")) {
	263	if (apb->state == ARCHE_PLATFORM_STATE_OFF)
	264	return count;
	265
80a057aa	266	poweroff_seq(pdev);
33d76291 VH	267	} else if (sysfs_streq(buf, "active")) {
	268	if (apb->state == ARCHE_PLATFORM_STATE_ACTIVE)
	269	return count;
	270
80a057aa	271	poweroff_seq(pdev);
af3aae10 VH	272	is_disabled = apb->init_disabled;
af3aae10 VH	273	apb->init_disabled = false;
80a057aa	274	ret = coldboot_seq(pdev);
af3aae10 VH	275	if (ret)
af3aae10 VH	276	apb->init_disabled = is_disabled;
33d76291 VH	277	} else if (sysfs_streq(buf, "standby")) {
	278	if (apb->state == ARCHE_PLATFORM_STATE_STANDBY)
	279	return count;
	280
80a057aa	281	ret = standby_boot_seq(pdev);
33d76291 VH	282	} else if (sysfs_streq(buf, "fw_flashing")) {
	283	if (apb->state == ARCHE_PLATFORM_STATE_FW_FLASHING)
	284	return count;
	285
cb026e39 SG	286	/*
	287	* First we want to make sure we power off everything
	288	* and then enter FW flashing state
	289	*/
80a057aa VH	290	poweroff_seq(pdev);
80a057aa VH	291	ret = fw_flashing_seq(pdev);
33d76291 VH	292	} else {
	293	dev_err(dev, "unknown state\n");
	294	ret = -EINVAL;
	295	}
	296
	297	return ret ? ret : count;
	298	}
	299
	300	static ssize_t state_show(struct device *dev,
	301	struct device_attribute attr, char buf)
	302	{
	303	struct arche_apb_ctrl_drvdata *apb = dev_get_drvdata(dev);
	304
	305	switch (apb->state) {
	306	case ARCHE_PLATFORM_STATE_OFF:
af3aae10 VH	307	return sprintf(buf, "off%s\n",
af3aae10 VH	308	apb->init_disabled ? ",disabled" : "");
33d76291 VH	309	case ARCHE_PLATFORM_STATE_ACTIVE:
	310	return sprintf(buf, "active\n");
	311	case ARCHE_PLATFORM_STATE_STANDBY:
	312	return sprintf(buf, "standby\n");
	313	case ARCHE_PLATFORM_STATE_FW_FLASHING:
	314	return sprintf(buf, "fw_flashing\n");
	315	default:
	316	return sprintf(buf, "unknown state\n");
	317	}
	318	}
	319
	320	static DEVICE_ATTR_RW(state);
	321
5a781787 VH	322	static int apb_ctrl_get_devtree_data(struct platform_device *pdev,
	323	struct arche_apb_ctrl_drvdata *apb)
	324	{
	325	struct device *dev = &pdev->dev;
	326	struct device_node *np = dev->of_node;
6ceed512	327	int ret;
5a781787	328
5a781787	329	apb->resetn_gpio = of_get_named_gpio(np, "reset-gpios", 0);
7541c1a1	330	if (apb->resetn_gpio < 0) {
5a781787 VH	331	dev_err(dev, "failed to get reset gpio\n");
	332	return apb->resetn_gpio;
	333	}
6ceed512 VH	334	ret = devm_gpio_request_one(dev, apb->resetn_gpio,
	335	GPIOF_OUT_INIT_LOW, "apb-reset");
	336	if (ret) {
	337	dev_err(dev, "Failed requesting reset gpio %d\n",
	338	apb->resetn_gpio);
	339	return ret;
	340	}
5a781787 VH	341
5a781787 VH	342	apb->boot_ret_gpio = of_get_named_gpio(np, "boot-ret-gpios", 0);
7541c1a1	343	if (apb->boot_ret_gpio < 0) {
5a781787 VH	344	dev_err(dev, "failed to get boot retention gpio\n");
	345	return apb->boot_ret_gpio;
	346	}
6ceed512 VH	347	ret = devm_gpio_request_one(dev, apb->boot_ret_gpio,
	348	GPIOF_OUT_INIT_LOW, "boot retention");
	349	if (ret) {
	350	dev_err(dev, "Failed requesting bootret gpio %d\n",
	351	apb->boot_ret_gpio);
	352	return ret;
	353	}
5a781787 VH	354
	355	/* It's not mandatory to support power management interface */
	356	apb->pwroff_gpio = of_get_named_gpio(np, "pwr-off-gpios", 0);
7541c1a1	357	if (apb->pwroff_gpio < 0) {
db0cff55	358	dev_err(dev, "failed to get power off gpio\n");
5a781787 VH	359	return apb->pwroff_gpio;
5a781787 VH	360	}
6ceed512 VH	361	ret = devm_gpio_request_one(dev, apb->pwroff_gpio,
	362	GPIOF_IN, "pwroff_n");
	363	if (ret) {
	364	dev_err(dev, "Failed requesting pwroff_n gpio %d\n",
	365	apb->pwroff_gpio);
	366	return ret;
	367	}
5a781787 VH	368
	369	/* Do not make clock mandatory as of now (for DB3) */
	370	apb->clk_en_gpio = of_get_named_gpio(np, "clock-en-gpio", 0);
6ceed512	371	if (apb->clk_en_gpio < 0) {
db0cff55	372	dev_warn(dev, "failed to get clock en gpio\n");
6ceed512 VH	373	} else if (gpio_is_valid(apb->clk_en_gpio)) {
	374	ret = devm_gpio_request_one(dev, apb->clk_en_gpio,
	375	GPIOF_OUT_INIT_LOW, "apb_clk_en");
	376	if (ret) {
	377	dev_warn(dev, "Failed requesting APB clock en gpio %d\n",
	378	apb->clk_en_gpio);
	379	return ret;
	380	}
	381	}
5a781787 VH	382
5a781787 VH	383	apb->pwrdn_gpio = of_get_named_gpio(np, "pwr-down-gpios", 0);
7541c1a1	384	if (apb->pwrdn_gpio < 0)
db0cff55	385	dev_warn(dev, "failed to get power down gpio\n");
5a781787 VH	386
	387	/* Regulators are optional, as we may have fixed supply coming in */
	388	apb->vcore = devm_regulator_get(dev, "vcore");
dcf77c39	389	if (IS_ERR(apb->vcore))
db0cff55	390	dev_warn(dev, "no core regulator found\n");
5a781787 VH	391
5a781787 VH	392	apb->vio = devm_regulator_get(dev, "vio");
dcf77c39	393	if (IS_ERR(apb->vio))
db0cff55	394	dev_warn(dev, "no IO regulator found\n");
5a781787 VH	395
	396	apb->pinctrl = devm_pinctrl_get(&pdev->dev);
	397	if (IS_ERR(apb->pinctrl)) {
	398	dev_err(&pdev->dev, "could not get pinctrl handle\n");
	399	return PTR_ERR(apb->pinctrl);
	400	}
	401	apb->pin_default = pinctrl_lookup_state(apb->pinctrl, "default");
	402	if (IS_ERR(apb->pin_default)) {
	403	dev_err(&pdev->dev, "could not get default pin state\n");
	404	return PTR_ERR(apb->pin_default);
	405	}
	406
921dbe52 VH	407	/* Only applicable for platform >= V2 */
	408	apb->spi_en_gpio = of_get_named_gpio(np, "spi-en-gpio", 0);
	409	if (apb->spi_en_gpio >= 0) {
	410	if (of_property_read_bool(pdev->dev.of_node,
	411	"spi-en-active-high"))
	412	apb->spi_en_polarity_high = true;
	413	}
	414
5a781787 VH	415	return 0;
	416	}
	417
7b62b61c	418	static int arche_apb_ctrl_probe(struct platform_device *pdev)
5a781787 VH	419	{
	420	int ret;
	421	struct arche_apb_ctrl_drvdata *apb;
	422	struct device *dev = &pdev->dev;
	423
	424	apb = devm_kzalloc(&pdev->dev, sizeof(*apb), GFP_KERNEL);
	425	if (!apb)
	426	return -ENOMEM;
	427
	428	ret = apb_ctrl_get_devtree_data(pdev, apb);
	429	if (ret) {
	430	dev_err(dev, "failed to get apb devicetree data %d\n", ret);
	431	return ret;
	432	}
	433
f2222a41 VH	434	/* Initially set APB to OFF state */
f2222a41 VH	435	apb->state = ARCHE_PLATFORM_STATE_OFF;
af3aae10	436	/* Check whether device needs to be enabled on boot */
20de72f5	437	if (of_property_read_bool(pdev->dev.of_node, "arche,init-disable"))
af3aae10	438	apb->init_disabled = true;
f2222a41	439
6961e046 VH	440	platform_set_drvdata(pdev, apb);
6961e046 VH	441
33d76291 VH	442	/* Create sysfs interface to allow user to change state dynamically */
	443	ret = device_create_file(dev, &dev_attr_state);
	444	if (ret) {
	445	dev_err(dev, "failed to create state file in sysfs\n");
	446	return ret;
	447	}
	448
5a781787 VH	449	dev_info(&pdev->dev, "Device registered successfully\n");
5a781787 VH	450	return 0;
5a781787 VH	451	}
5a781787 VH	452
7b62b61c	453	static int arche_apb_ctrl_remove(struct platform_device *pdev)
5a781787	454	{
33d76291	455	device_remove_file(&pdev->dev, &dev_attr_state);
80a057aa	456	poweroff_seq(pdev);
5a781787 VH	457	platform_set_drvdata(pdev, NULL);
	458
	459	return 0;
	460	}
	461
6da80863	462	static int __maybe_unused arche_apb_ctrl_suspend(struct device *dev)
5a781787 VH	463	{
5a781787 VH	464	/*
3b538c39	465	* If timing profile permits, we may shutdown bridge
5a781787 VH	466	* completely
	467	*
	468	* TODO: sequence ??
	469	*
	470	* Also, need to make sure we meet precondition for unipro suspend
	471	* Precondition: Definition ???
	472	*/
	473	return 0;
	474	}
	475
6da80863	476	static int __maybe_unused arche_apb_ctrl_resume(struct device *dev)
5a781787 VH	477	{
	478	/*
	479	* Atleast for ES2 we have to meet the delay requirement between
	480	* unipro switch and AP bridge init, depending on whether bridge is in
	481	* OFF state or standby state.
	482	*
	483	* Based on whether bridge is in standby or OFF state we may have to
	484	* assert multiple signals. Please refer to WDM spec, for more info.
	485	*
	486	*/
	487	return 0;
	488	}
	489
1f77b363 DL	490	static void arche_apb_ctrl_shutdown(struct platform_device *pdev)
	491	{
	492	apb_ctrl_poweroff(&pdev->dev);
	493	}
	494
7b62b61c VK	495	static SIMPLE_DEV_PM_OPS(arche_apb_ctrl_pm_ops, arche_apb_ctrl_suspend,
	496	arche_apb_ctrl_resume);
	497
5c925fe2	498	static const struct of_device_id arche_apb_ctrl_of_match[] = {
7b62b61c VK	499	{ .compatible = "usbffff,2", },
	500	{ },
	501	};
	502
	503	static struct platform_driver arche_apb_ctrl_device_driver = {
	504	.probe = arche_apb_ctrl_probe,
	505	.remove = arche_apb_ctrl_remove,
1f77b363	506	.shutdown = arche_apb_ctrl_shutdown,
7b62b61c VK	507	.driver = {
	508	.name = "arche-apb-ctrl",
	509	.pm = &arche_apb_ctrl_pm_ops,
	510	.of_match_table = arche_apb_ctrl_of_match,
	511	}
	512	};
	513
	514	int __init arche_apb_init(void)
	515	{
	516	return platform_driver_register(&arche_apb_ctrl_device_driver);
	517	}
	518
	519	void __exit arche_apb_exit(void)
	520	{
	521	platform_driver_unregister(&arche_apb_ctrl_device_driver);
	522	}