[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"


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 */
}

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

	gpio_set_value(apb->boot_ret_gpio, 1);
}

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 VH	24
	25	struct arche_apb_ctrl_drvdata {
	26	/* Control GPIO signals to and from AP <=> AP Bridges */
5a781787 VH	27	int resetn_gpio;
	28	int boot_ret_gpio;
	29	int pwroff_gpio;
	30	int wake_in_gpio;
	31	int wake_out_gpio;
	32	int pwrdn_gpio;
	33
a821adb4	34	enum arche_platform_state state;
af3aae10	35	bool init_disabled;
5a781787 VH	36
	37	struct regulator *vcore;
	38	struct regulator *vio;
	39
7fe93014	40	int clk_en_gpio;
5a781787 VH	41	struct clk *clk;
	42
	43	struct pinctrl *pinctrl;
	44	struct pinctrl_state *pin_default;
921dbe52 VH	45
	46	/* V2: SPI Bus control */
	47	int spi_en_gpio;
	48	bool spi_en_polarity_high;
5a781787 VH	49	};
	50
	51	/*
	52	* Note that these low level api's are active high
	53	*/
f1e9cbd5	54	static inline void deassert_reset(unsigned int gpio)
5a781787 VH	55	{
5a781787 VH	56	gpio_set_value(gpio, 1);
5a781787 VH	57	}
5a781787 VH	58
f1e9cbd5	59	static inline void assert_reset(unsigned int gpio)
5a781787 VH	60	{
	61	gpio_set_value(gpio, 0);
	62	}
	63
5a781787 VH	64	/*
	65	* Note: Please do not modify the below sequence, as it is as per the spec
	66	*/
80a057aa	67	static int coldboot_seq(struct platform_device *pdev)
5a781787 VH	68	{
5a781787 VH	69	struct device *dev = &pdev->dev;
6961e046	70	struct arche_apb_ctrl_drvdata *apb = platform_get_drvdata(pdev);
5a781787 VH	71	int ret;
5a781787 VH	72
c5e7cbaf VH	73	if (apb->init_disabled \|\|
c5e7cbaf VH	74	apb->state == ARCHE_PLATFORM_STATE_ACTIVE)
af3aae10 VH	75	return 0;
af3aae10 VH	76
5a781787	77	/* Hold APB in reset state */
6ceed512	78	assert_reset(apb->resetn_gpio);
5a781787	79
921dbe52 VH	80	if (apb->state == ARCHE_PLATFORM_STATE_FW_FLASHING &&
	81	gpio_is_valid(apb->spi_en_gpio))
	82	devm_gpio_free(dev, apb->spi_en_gpio);
	83
5a781787	84	/* Enable power to APB */
dcf77c39	85	if (!IS_ERR(apb->vcore)) {
5a781787 VH	86	ret = regulator_enable(apb->vcore);
	87	if (ret) {
	88	dev_err(dev, "failed to enable core regulator\n");
	89	return ret;
	90	}
	91	}
aa187d33	92
dcf77c39	93	if (!IS_ERR(apb->vio)) {
5a781787 VH	94	ret = regulator_enable(apb->vio);
	95	if (ret) {
	96	dev_err(dev, "failed to enable IO regulator\n");
6ceed512	97	return ret;
5a781787 VH	98	}
	99	}
	100
970dc85b	101	apb_bootret_deassert(dev);
aa187d33 VH	102
aa187d33 VH	103	/* On DB3 clock was not mandatory */
6ceed512 VH	104	if (gpio_is_valid(apb->clk_en_gpio))
6ceed512 VH	105	gpio_set_value(apb->clk_en_gpio, 1);
aa187d33 VH	106
aa187d33 VH	107	usleep_range(100, 200);
5a781787	108
6ceed512 VH	109	/* deassert reset to APB : Active-low signal */
6ceed512 VH	110	deassert_reset(apb->resetn_gpio);
d258432f	111
6ceed512	112	apb->state = ARCHE_PLATFORM_STATE_ACTIVE;
5a781787	113
6ceed512	114	return 0;
5a781787 VH	115	}
5a781787 VH	116
80a057aa	117	static int fw_flashing_seq(struct platform_device *pdev)
33d76291 VH	118	{
	119	struct device *dev = &pdev->dev;
	120	struct arche_apb_ctrl_drvdata *apb = platform_get_drvdata(pdev);
	121	int ret;
	122
c5e7cbaf VH	123	if (apb->init_disabled \|\|
c5e7cbaf VH	124	apb->state == ARCHE_PLATFORM_STATE_FW_FLASHING)
af3aae10 VH	125	return 0;
af3aae10 VH	126
33d76291 VH	127	ret = regulator_enable(apb->vcore);
	128	if (ret) {
	129	dev_err(dev, "failed to enable core regulator\n");
	130	return ret;
	131	}
	132
	133	ret = regulator_enable(apb->vio);
	134	if (ret) {
	135	dev_err(dev, "failed to enable IO regulator\n");
	136	return ret;
	137	}
	138
921dbe52 VH	139	if (gpio_is_valid(apb->spi_en_gpio)) {
	140	unsigned long flags;
	141
	142	if (apb->spi_en_polarity_high)
	143	flags = GPIOF_OUT_INIT_HIGH;
	144	else
	145	flags = GPIOF_OUT_INIT_LOW;
	146
	147	ret = devm_gpio_request_one(dev, apb->spi_en_gpio,
	148	flags, "apb_spi_en");
	149	if (ret) {
	150	dev_err(dev, "Failed requesting SPI bus en gpio %d\n",
	151	apb->spi_en_gpio);
	152	return ret;
	153	}
	154	}
	155
33d76291 VH	156	/* for flashing device should be in reset state */
	157	assert_reset(apb->resetn_gpio);
	158	apb->state = ARCHE_PLATFORM_STATE_FW_FLASHING;
	159
	160	return 0;
	161	}
	162
80a057aa	163	static int standby_boot_seq(struct platform_device *pdev)
33d76291	164	{
921dbe52	165	struct device *dev = &pdev->dev;
33d76291 VH	166	struct arche_apb_ctrl_drvdata *apb = platform_get_drvdata(pdev);
33d76291 VH	167
af3aae10 VH	168	if (apb->init_disabled)
	169	return 0;
	170
461ab807 GK	171	/*
	172	* Even if it is in OFF state,
	173	* then we do not want to change the state
	174	*/
c5e7cbaf VH	175	if (apb->state == ARCHE_PLATFORM_STATE_STANDBY \|\|
c5e7cbaf VH	176	apb->state == ARCHE_PLATFORM_STATE_OFF)
33d76291 VH	177	return 0;
33d76291 VH	178
921dbe52 VH	179	if (apb->state == ARCHE_PLATFORM_STATE_FW_FLASHING &&
	180	gpio_is_valid(apb->spi_en_gpio))
	181	devm_gpio_free(dev, apb->spi_en_gpio);
	182
33d76291 VH	183	/*
	184	* As per WDM spec, do nothing
	185	*
	186	* Pasted from WDM spec,
	187	* - A falling edge on POWEROFF_L is detected (a)
	188	* - WDM enters standby mode, but no output signals are changed
1047cc13	189	*/
33d76291 VH	190
	191	/* TODO: POWEROFF_L is input to WDM module */
	192	apb->state = ARCHE_PLATFORM_STATE_STANDBY;
	193	return 0;
	194	}
	195
80a057aa	196	static void poweroff_seq(struct platform_device *pdev)
5667ab17	197	{
921dbe52	198	struct device *dev = &pdev->dev;
6961e046 VH	199	struct arche_apb_ctrl_drvdata *apb = platform_get_drvdata(pdev);
6961e046 VH	200
c5e7cbaf	201	if (apb->init_disabled \|\| apb->state == ARCHE_PLATFORM_STATE_OFF)
af3aae10 VH	202	return;
af3aae10 VH	203
921dbe52 VH	204	if (apb->state == ARCHE_PLATFORM_STATE_FW_FLASHING &&
	205	gpio_is_valid(apb->spi_en_gpio))
	206	devm_gpio_free(dev, apb->spi_en_gpio);
	207
5667ab17 VH	208	/* disable the clock */
	209	if (gpio_is_valid(apb->clk_en_gpio))
	210	gpio_set_value(apb->clk_en_gpio, 0);
	211
	212	if (!IS_ERR(apb->vcore) && regulator_is_enabled(apb->vcore) > 0)
	213	regulator_disable(apb->vcore);
	214
	215	if (!IS_ERR(apb->vio) && regulator_is_enabled(apb->vio) > 0)
	216	regulator_disable(apb->vio);
	217
	218	/* As part of exit, put APB back in reset state */
	219	assert_reset(apb->resetn_gpio);
	220	apb->state = ARCHE_PLATFORM_STATE_OFF;
	221
	222	/* TODO: May have to send an event to SVC about this exit */
	223	}
	224
970dc85b BD	225	void apb_bootret_assert(struct device *dev)
	226	{
	227	struct arche_apb_ctrl_drvdata *apb = dev_get_drvdata(dev);
	228
	229	gpio_set_value(apb->boot_ret_gpio, 1);
	230	}
	231
	232	void apb_bootret_deassert(struct device *dev)
	233	{
	234	struct arche_apb_ctrl_drvdata *apb = dev_get_drvdata(dev);
	235
	236	gpio_set_value(apb->boot_ret_gpio, 0);
	237	}
	238
65fd5a50 VH	239	int apb_ctrl_coldboot(struct device *dev)
	240	{
	241	return coldboot_seq(to_platform_device(dev));
	242	}
	243
	244	int apb_ctrl_fw_flashing(struct device *dev)
	245	{
	246	return fw_flashing_seq(to_platform_device(dev));
	247	}
	248
	249	int apb_ctrl_standby_boot(struct device *dev)
	250	{
	251	return standby_boot_seq(to_platform_device(dev));
	252	}
	253
	254	void apb_ctrl_poweroff(struct device *dev)
	255	{
	256	poweroff_seq(to_platform_device(dev));
	257	}
	258
33d76291 VH	259	static ssize_t state_store(struct device *dev,
	260	struct device_attribute attr, const char buf, size_t count)
	261	{
	262	struct platform_device *pdev = to_platform_device(dev);
	263	struct arche_apb_ctrl_drvdata *apb = platform_get_drvdata(pdev);
	264	int ret = 0;
af3aae10	265	bool is_disabled;
33d76291 VH	266
	267	if (sysfs_streq(buf, "off")) {
	268	if (apb->state == ARCHE_PLATFORM_STATE_OFF)
	269	return count;
	270
80a057aa	271	poweroff_seq(pdev);
33d76291 VH	272	} else if (sysfs_streq(buf, "active")) {
	273	if (apb->state == ARCHE_PLATFORM_STATE_ACTIVE)
	274	return count;
	275
80a057aa	276	poweroff_seq(pdev);
af3aae10 VH	277	is_disabled = apb->init_disabled;
af3aae10 VH	278	apb->init_disabled = false;
80a057aa	279	ret = coldboot_seq(pdev);
af3aae10 VH	280	if (ret)
af3aae10 VH	281	apb->init_disabled = is_disabled;
33d76291 VH	282	} else if (sysfs_streq(buf, "standby")) {
	283	if (apb->state == ARCHE_PLATFORM_STATE_STANDBY)
	284	return count;
	285
80a057aa	286	ret = standby_boot_seq(pdev);
33d76291 VH	287	} else if (sysfs_streq(buf, "fw_flashing")) {
	288	if (apb->state == ARCHE_PLATFORM_STATE_FW_FLASHING)
	289	return count;
	290
cb026e39 SG	291	/*
	292	* First we want to make sure we power off everything
	293	* and then enter FW flashing state
	294	*/
80a057aa VH	295	poweroff_seq(pdev);
80a057aa VH	296	ret = fw_flashing_seq(pdev);
33d76291 VH	297	} else {
	298	dev_err(dev, "unknown state\n");
	299	ret = -EINVAL;
	300	}
	301
	302	return ret ? ret : count;
	303	}
	304
	305	static ssize_t state_show(struct device *dev,
	306	struct device_attribute attr, char buf)
	307	{
	308	struct arche_apb_ctrl_drvdata *apb = dev_get_drvdata(dev);
	309
	310	switch (apb->state) {
	311	case ARCHE_PLATFORM_STATE_OFF:
af3aae10 VH	312	return sprintf(buf, "off%s\n",
af3aae10 VH	313	apb->init_disabled ? ",disabled" : "");
33d76291 VH	314	case ARCHE_PLATFORM_STATE_ACTIVE:
	315	return sprintf(buf, "active\n");
	316	case ARCHE_PLATFORM_STATE_STANDBY:
	317	return sprintf(buf, "standby\n");
	318	case ARCHE_PLATFORM_STATE_FW_FLASHING:
	319	return sprintf(buf, "fw_flashing\n");
	320	default:
	321	return sprintf(buf, "unknown state\n");
	322	}
	323	}
	324
	325	static DEVICE_ATTR_RW(state);
	326
5a781787 VH	327	static int apb_ctrl_get_devtree_data(struct platform_device *pdev,
	328	struct arche_apb_ctrl_drvdata *apb)
	329	{
	330	struct device *dev = &pdev->dev;
	331	struct device_node *np = dev->of_node;
6ceed512	332	int ret;
5a781787	333
5a781787	334	apb->resetn_gpio = of_get_named_gpio(np, "reset-gpios", 0);
7541c1a1	335	if (apb->resetn_gpio < 0) {
5a781787 VH	336	dev_err(dev, "failed to get reset gpio\n");
	337	return apb->resetn_gpio;
	338	}
6ceed512 VH	339	ret = devm_gpio_request_one(dev, apb->resetn_gpio,
	340	GPIOF_OUT_INIT_LOW, "apb-reset");
	341	if (ret) {
	342	dev_err(dev, "Failed requesting reset gpio %d\n",
	343	apb->resetn_gpio);
	344	return ret;
	345	}
5a781787 VH	346
5a781787 VH	347	apb->boot_ret_gpio = of_get_named_gpio(np, "boot-ret-gpios", 0);
7541c1a1	348	if (apb->boot_ret_gpio < 0) {
5a781787 VH	349	dev_err(dev, "failed to get boot retention gpio\n");
	350	return apb->boot_ret_gpio;
	351	}
6ceed512 VH	352	ret = devm_gpio_request_one(dev, apb->boot_ret_gpio,
	353	GPIOF_OUT_INIT_LOW, "boot retention");
	354	if (ret) {
	355	dev_err(dev, "Failed requesting bootret gpio %d\n",
	356	apb->boot_ret_gpio);
	357	return ret;
	358	}
5a781787 VH	359
	360	/* It's not mandatory to support power management interface */
	361	apb->pwroff_gpio = of_get_named_gpio(np, "pwr-off-gpios", 0);
7541c1a1	362	if (apb->pwroff_gpio < 0) {
db0cff55	363	dev_err(dev, "failed to get power off gpio\n");
5a781787 VH	364	return apb->pwroff_gpio;
5a781787 VH	365	}
6ceed512 VH	366	ret = devm_gpio_request_one(dev, apb->pwroff_gpio,
	367	GPIOF_IN, "pwroff_n");
	368	if (ret) {
	369	dev_err(dev, "Failed requesting pwroff_n gpio %d\n",
	370	apb->pwroff_gpio);
	371	return ret;
	372	}
5a781787 VH	373
	374	/* Do not make clock mandatory as of now (for DB3) */
	375	apb->clk_en_gpio = of_get_named_gpio(np, "clock-en-gpio", 0);
6ceed512	376	if (apb->clk_en_gpio < 0) {
db0cff55	377	dev_warn(dev, "failed to get clock en gpio\n");
6ceed512 VH	378	} else if (gpio_is_valid(apb->clk_en_gpio)) {
	379	ret = devm_gpio_request_one(dev, apb->clk_en_gpio,
	380	GPIOF_OUT_INIT_LOW, "apb_clk_en");
	381	if (ret) {
	382	dev_warn(dev, "Failed requesting APB clock en gpio %d\n",
	383	apb->clk_en_gpio);
	384	return ret;
	385	}
	386	}
5a781787 VH	387
5a781787 VH	388	apb->pwrdn_gpio = of_get_named_gpio(np, "pwr-down-gpios", 0);
7541c1a1	389	if (apb->pwrdn_gpio < 0)
db0cff55	390	dev_warn(dev, "failed to get power down gpio\n");
5a781787 VH	391
	392	/* Regulators are optional, as we may have fixed supply coming in */
	393	apb->vcore = devm_regulator_get(dev, "vcore");
dcf77c39	394	if (IS_ERR(apb->vcore))
db0cff55	395	dev_warn(dev, "no core regulator found\n");
5a781787 VH	396
5a781787 VH	397	apb->vio = devm_regulator_get(dev, "vio");
dcf77c39	398	if (IS_ERR(apb->vio))
db0cff55	399	dev_warn(dev, "no IO regulator found\n");
5a781787 VH	400
	401	apb->pinctrl = devm_pinctrl_get(&pdev->dev);
	402	if (IS_ERR(apb->pinctrl)) {
	403	dev_err(&pdev->dev, "could not get pinctrl handle\n");
	404	return PTR_ERR(apb->pinctrl);
	405	}
	406	apb->pin_default = pinctrl_lookup_state(apb->pinctrl, "default");
	407	if (IS_ERR(apb->pin_default)) {
	408	dev_err(&pdev->dev, "could not get default pin state\n");
	409	return PTR_ERR(apb->pin_default);
	410	}
	411
921dbe52 VH	412	/* Only applicable for platform >= V2 */
	413	apb->spi_en_gpio = of_get_named_gpio(np, "spi-en-gpio", 0);
	414	if (apb->spi_en_gpio >= 0) {
	415	if (of_property_read_bool(pdev->dev.of_node,
	416	"spi-en-active-high"))
	417	apb->spi_en_polarity_high = true;
	418	}
	419
5a781787 VH	420	return 0;
	421	}
	422
7b62b61c	423	static int arche_apb_ctrl_probe(struct platform_device *pdev)
5a781787 VH	424	{
	425	int ret;
	426	struct arche_apb_ctrl_drvdata *apb;
	427	struct device *dev = &pdev->dev;
	428
	429	apb = devm_kzalloc(&pdev->dev, sizeof(*apb), GFP_KERNEL);
	430	if (!apb)
	431	return -ENOMEM;
	432
	433	ret = apb_ctrl_get_devtree_data(pdev, apb);
	434	if (ret) {
	435	dev_err(dev, "failed to get apb devicetree data %d\n", ret);
	436	return ret;
	437	}
	438
f2222a41 VH	439	/* Initially set APB to OFF state */
f2222a41 VH	440	apb->state = ARCHE_PLATFORM_STATE_OFF;
af3aae10	441	/* Check whether device needs to be enabled on boot */
20de72f5	442	if (of_property_read_bool(pdev->dev.of_node, "arche,init-disable"))
af3aae10	443	apb->init_disabled = true;
f2222a41	444
6961e046 VH	445	platform_set_drvdata(pdev, apb);
6961e046 VH	446
33d76291 VH	447	/* Create sysfs interface to allow user to change state dynamically */
	448	ret = device_create_file(dev, &dev_attr_state);
	449	if (ret) {
	450	dev_err(dev, "failed to create state file in sysfs\n");
	451	return ret;
	452	}
	453
5a781787 VH	454	dev_info(&pdev->dev, "Device registered successfully\n");
5a781787 VH	455	return 0;
5a781787 VH	456	}
5a781787 VH	457
7b62b61c	458	static int arche_apb_ctrl_remove(struct platform_device *pdev)
5a781787	459	{
33d76291	460	device_remove_file(&pdev->dev, &dev_attr_state);
80a057aa	461	poweroff_seq(pdev);
5a781787 VH	462	platform_set_drvdata(pdev, NULL);
	463
	464	return 0;
	465	}
	466
6da80863	467	static int __maybe_unused arche_apb_ctrl_suspend(struct device *dev)
5a781787 VH	468	{
5a781787 VH	469	/*
3b538c39	470	* If timing profile permits, we may shutdown bridge
5a781787 VH	471	* completely
	472	*
	473	* TODO: sequence ??
	474	*
	475	* Also, need to make sure we meet precondition for unipro suspend
	476	* Precondition: Definition ???
	477	*/
	478	return 0;
	479	}
	480
6da80863	481	static int __maybe_unused arche_apb_ctrl_resume(struct device *dev)
5a781787 VH	482	{
	483	/*
	484	* Atleast for ES2 we have to meet the delay requirement between
	485	* unipro switch and AP bridge init, depending on whether bridge is in
	486	* OFF state or standby state.
	487	*
	488	* Based on whether bridge is in standby or OFF state we may have to
	489	* assert multiple signals. Please refer to WDM spec, for more info.
	490	*
	491	*/
	492	return 0;
	493	}
	494
1f77b363 DL	495	static void arche_apb_ctrl_shutdown(struct platform_device *pdev)
	496	{
	497	apb_ctrl_poweroff(&pdev->dev);
	498	}
	499
7b62b61c VK	500	static SIMPLE_DEV_PM_OPS(arche_apb_ctrl_pm_ops, arche_apb_ctrl_suspend,
	501	arche_apb_ctrl_resume);
	502
5c925fe2	503	static const struct of_device_id arche_apb_ctrl_of_match[] = {
7b62b61c VK	504	{ .compatible = "usbffff,2", },
	505	{ },
	506	};
	507
	508	static struct platform_driver arche_apb_ctrl_device_driver = {
	509	.probe = arche_apb_ctrl_probe,
	510	.remove = arche_apb_ctrl_remove,
1f77b363	511	.shutdown = arche_apb_ctrl_shutdown,
7b62b61c VK	512	.driver = {
	513	.name = "arche-apb-ctrl",
	514	.pm = &arche_apb_ctrl_pm_ops,
	515	.of_match_table = arche_apb_ctrl_of_match,
	516	}
	517	};
	518
	519	int __init arche_apb_init(void)
	520	{
	521	return platform_driver_register(&arche_apb_ctrl_device_driver);
	522	}
	523
	524	void __exit arche_apb_exit(void)
	525	{
	526	platform_driver_unregister(&arche_apb_ctrl_device_driver);
	527	}