[linux-block.git] / drivers / usb / misc / qcom_eud.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2015-2021, The Linux Foundation. All rights reserved.
 */

#include <linux/bitops.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/usb/role.h>

#define EUD_REG_INT1_EN_MASK	0x0024
#define EUD_REG_INT_STATUS_1	0x0044
#define EUD_REG_CTL_OUT_1	0x0074
#define EUD_REG_VBUS_INT_CLR	0x0080
#define EUD_REG_CSR_EUD_EN	0x1014
#define EUD_REG_SW_ATTACH_DET	0x1018
#define EUD_REG_EUD_EN2        0x0000

#define EUD_ENABLE		BIT(0)
#define EUD_INT_PET_EUD	BIT(0)
#define EUD_INT_VBUS		BIT(2)
#define EUD_INT_SAFE_MODE	BIT(4)
#define EUD_INT_ALL		(EUD_INT_VBUS | EUD_INT_SAFE_MODE)

struct eud_chip {
	struct device			*dev;
	struct usb_role_switch		*role_sw;
	void __iomem			*base;
	void __iomem			*mode_mgr;
	unsigned int			int_status;
	int				irq;
	bool				enabled;
	bool				usb_attached;
};

static int enable_eud(struct eud_chip *priv)
{
	writel(EUD_ENABLE, priv->base + EUD_REG_CSR_EUD_EN);
	writel(EUD_INT_VBUS | EUD_INT_SAFE_MODE,
			priv->base + EUD_REG_INT1_EN_MASK);
	writel(1, priv->mode_mgr + EUD_REG_EUD_EN2);

	return usb_role_switch_set_role(priv->role_sw, USB_ROLE_DEVICE);
}

static void disable_eud(struct eud_chip *priv)
{
	writel(0, priv->base + EUD_REG_CSR_EUD_EN);
	writel(0, priv->mode_mgr + EUD_REG_EUD_EN2);
}

static ssize_t enable_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct eud_chip *chip = dev_get_drvdata(dev);

	return sysfs_emit(buf, "%d\n", chip->enabled);
}

static ssize_t enable_store(struct device *dev,
		struct device_attribute *attr,
		const char *buf, size_t count)
{
	struct eud_chip *chip = dev_get_drvdata(dev);
	bool enable;
	int ret;

	if (kstrtobool(buf, &enable))
		return -EINVAL;

	if (enable) {
		ret = enable_eud(chip);
		if (!ret)
			chip->enabled = enable;
		else
			disable_eud(chip);
	} else {
		disable_eud(chip);
	}

	return count;
}

static DEVICE_ATTR_RW(enable);

static struct attribute *eud_attrs[] = {
	&dev_attr_enable.attr,
	NULL,
};
ATTRIBUTE_GROUPS(eud);

static void usb_attach_detach(struct eud_chip *chip)
{
	u32 reg;

	/* read ctl_out_1[4] to find USB attach or detach event */
	reg = readl(chip->base + EUD_REG_CTL_OUT_1);
	chip->usb_attached = reg & EUD_INT_SAFE_MODE;
}

static void pet_eud(struct eud_chip *chip)
{
	u32 reg;
	int ret;

	/* When the EUD_INT_PET_EUD in SW_ATTACH_DET is set, the cable has been
	 * disconnected and we need to detach the pet to check if EUD is in safe
	 * mode before attaching again.
	 */
	reg = readl(chip->base + EUD_REG_SW_ATTACH_DET);
	if (reg & EUD_INT_PET_EUD) {
		/* Detach & Attach pet for EUD */
		writel(0, chip->base + EUD_REG_SW_ATTACH_DET);
		/* Delay to make sure detach pet is done before attach pet */
		ret = readl_poll_timeout(chip->base + EUD_REG_SW_ATTACH_DET,
					reg, (reg == 0), 1, 100);
		if (ret) {
			dev_err(chip->dev, "Detach pet failed\n");
			return;
		}
	}
	/* Attach pet for EUD */
	writel(EUD_INT_PET_EUD, chip->base + EUD_REG_SW_ATTACH_DET);
}

static irqreturn_t handle_eud_irq(int irq, void *data)
{
	struct eud_chip *chip = data;
	u32 reg;

	reg = readl(chip->base + EUD_REG_INT_STATUS_1);
	switch (reg & EUD_INT_ALL) {
	case EUD_INT_VBUS:
		usb_attach_detach(chip);
		return IRQ_WAKE_THREAD;
	case EUD_INT_SAFE_MODE:
		pet_eud(chip);
		return IRQ_HANDLED;
	default:
		return IRQ_NONE;
	}
}

static irqreturn_t handle_eud_irq_thread(int irq, void *data)
{
	struct eud_chip *chip = data;
	int ret;

	if (chip->usb_attached)
		ret = usb_role_switch_set_role(chip->role_sw, USB_ROLE_DEVICE);
	else
		ret = usb_role_switch_set_role(chip->role_sw, USB_ROLE_HOST);
	if (ret)
		dev_err(chip->dev, "failed to set role switch\n");

	/* set and clear vbus_int_clr[0] to clear interrupt */
	writel(BIT(0), chip->base + EUD_REG_VBUS_INT_CLR);
	writel(0, chip->base + EUD_REG_VBUS_INT_CLR);

	return IRQ_HANDLED;
}

static void eud_role_switch_release(void *data)
{
	struct eud_chip *chip = data;

	usb_role_switch_put(chip->role_sw);
}

static int eud_probe(struct platform_device *pdev)
{
	struct eud_chip *chip;
	int ret;

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

	chip->dev = &pdev->dev;

	chip->role_sw = usb_role_switch_get(&pdev->dev);
	if (IS_ERR(chip->role_sw))
		return dev_err_probe(chip->dev, PTR_ERR(chip->role_sw),
					"failed to get role switch\n");

	ret = devm_add_action_or_reset(chip->dev, eud_role_switch_release, chip);
	if (ret)
		return dev_err_probe(chip->dev, ret,
				"failed to add role switch release action\n");

	chip->base = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(chip->base))
		return PTR_ERR(chip->base);

	chip->mode_mgr = devm_platform_ioremap_resource(pdev, 1);
	if (IS_ERR(chip->mode_mgr))
		return PTR_ERR(chip->mode_mgr);

	chip->irq = platform_get_irq(pdev, 0);
	ret = devm_request_threaded_irq(&pdev->dev, chip->irq, handle_eud_irq,
			handle_eud_irq_thread, IRQF_ONESHOT, NULL, chip);
	if (ret)
		return dev_err_probe(chip->dev, ret, "failed to allocate irq\n");

	enable_irq_wake(chip->irq);

	platform_set_drvdata(pdev, chip);

	return 0;
}

static int eud_remove(struct platform_device *pdev)
{
	struct eud_chip *chip = platform_get_drvdata(pdev);

	if (chip->enabled)
		disable_eud(chip);

	device_init_wakeup(&pdev->dev, false);
	disable_irq_wake(chip->irq);

	return 0;
}

static const struct of_device_id eud_dt_match[] = {
	{ .compatible = "qcom,sc7280-eud" },
	{ }
};
MODULE_DEVICE_TABLE(of, eud_dt_match);

static struct platform_driver eud_driver = {
	.probe	= eud_probe,
	.remove	= eud_remove,
	.driver	= {
		.name = "qcom_eud",
		.dev_groups = eud_groups,
		.of_match_table = eud_dt_match,
	},
};
module_platform_driver(eud_driver);

MODULE_DESCRIPTION("QTI EUD driver");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
9a1bf58c SC	1	// SPDX-License-Identifier: GPL-2.0-only
	2	/*
	3	* Copyright (c) 2015-2021, The Linux Foundation. All rights reserved.
	4	*/
	5
	6	#include <linux/bitops.h>
	7	#include <linux/err.h>
	8	#include <linux/interrupt.h>
	9	#include <linux/io.h>
	10	#include <linux/iopoll.h>
	11	#include <linux/kernel.h>
	12	#include <linux/module.h>
	13	#include <linux/of.h>
	14	#include <linux/platform_device.h>
	15	#include <linux/slab.h>
	16	#include <linux/sysfs.h>
	17	#include <linux/usb/role.h>
	18
	19	#define EUD_REG_INT1_EN_MASK 0x0024
	20	#define EUD_REG_INT_STATUS_1 0x0044
	21	#define EUD_REG_CTL_OUT_1 0x0074
	22	#define EUD_REG_VBUS_INT_CLR 0x0080
	23	#define EUD_REG_CSR_EUD_EN 0x1014
	24	#define EUD_REG_SW_ATTACH_DET 0x1018
	25	#define EUD_REG_EUD_EN2 0x0000
	26
	27	#define EUD_ENABLE BIT(0)
	28	#define EUD_INT_PET_EUD BIT(0)
	29	#define EUD_INT_VBUS BIT(2)
	30	#define EUD_INT_SAFE_MODE BIT(4)
	31	#define EUD_INT_ALL (EUD_INT_VBUS \| EUD_INT_SAFE_MODE)
	32
	33	struct eud_chip {
	34	struct device *dev;
	35	struct usb_role_switch *role_sw;
	36	void __iomem *base;
	37	void __iomem *mode_mgr;
	38	unsigned int int_status;
	39	int irq;
	40	bool enabled;
	41	bool usb_attached;
	42	};
	43
	44	static int enable_eud(struct eud_chip *priv)
	45	{
	46	writel(EUD_ENABLE, priv->base + EUD_REG_CSR_EUD_EN);
	47	writel(EUD_INT_VBUS \| EUD_INT_SAFE_MODE,
	48	priv->base + EUD_REG_INT1_EN_MASK);
	49	writel(1, priv->mode_mgr + EUD_REG_EUD_EN2);
	50
	51	return usb_role_switch_set_role(priv->role_sw, USB_ROLE_DEVICE);
	52	}
	53
	54	static void disable_eud(struct eud_chip *priv)
	55	{
	56	writel(0, priv->base + EUD_REG_CSR_EUD_EN);
	57	writel(0, priv->mode_mgr + EUD_REG_EUD_EN2);
	58	}
	59
	60	static ssize_t enable_show(struct device *dev,
	61	struct device_attribute attr, char buf)
	62	{
	63	struct eud_chip *chip = dev_get_drvdata(dev);
	64
65	return sysfs_emit(buf, "%d\n", chip->enabled);
66	}
67
68	static ssize_t enable_store(struct device *dev,
69	struct device_attribute *attr,
70	const char *buf, size_t count)
71	{
72	struct eud_chip *chip = dev_get_drvdata(dev);
73	bool enable;
74	int ret;
75
76	if (kstrtobool(buf, &enable))
77	return -EINVAL;
78
79	if (enable) {
80	ret = enable_eud(chip);
81	if (!ret)
82	chip->enabled = enable;
83	else
84	disable_eud(chip);
85	} else {
86	disable_eud(chip);
87	}
88
89	return count;
90	}
91
92	static DEVICE_ATTR_RW(enable);
93
94	static struct attribute *eud_attrs[] = {
95	&dev_attr_enable.attr,
96	NULL,
97	};
98	ATTRIBUTE_GROUPS(eud);
99
100	static void usb_attach_detach(struct eud_chip *chip)
101	{
102	u32 reg;
103
104	/* read ctl_out_1[4] to find USB attach or detach event */
105	reg = readl(chip->base + EUD_REG_CTL_OUT_1);
106	chip->usb_attached = reg & EUD_INT_SAFE_MODE;
107	}
108
109	static void pet_eud(struct eud_chip *chip)
110	{
111	u32 reg;
112	int ret;
113
114	/* When the EUD_INT_PET_EUD in SW_ATTACH_DET is set, the cable has been
115	* disconnected and we need to detach the pet to check if EUD is in safe
116	* mode before attaching again.
117	*/
118	reg = readl(chip->base + EUD_REG_SW_ATTACH_DET);
119	if (reg & EUD_INT_PET_EUD) {
120	/* Detach & Attach pet for EUD */
121	writel(0, chip->base + EUD_REG_SW_ATTACH_DET);
122	/* Delay to make sure detach pet is done before attach pet */
123	ret = readl_poll_timeout(chip->base + EUD_REG_SW_ATTACH_DET,
124	reg, (reg == 0), 1, 100);
125	if (ret) {
126	dev_err(chip->dev, "Detach pet failed\n");
127	return;
128	}
129	}
130	/* Attach pet for EUD */
131	writel(EUD_INT_PET_EUD, chip->base + EUD_REG_SW_ATTACH_DET);
132	}
133
134	static irqreturn_t handle_eud_irq(int irq, void *data)
135	{
136	struct eud_chip *chip = data;
137	u32 reg;
138
139	reg = readl(chip->base + EUD_REG_INT_STATUS_1);
140	switch (reg & EUD_INT_ALL) {
141	case EUD_INT_VBUS:
142	usb_attach_detach(chip);
143	return IRQ_WAKE_THREAD;
144	case EUD_INT_SAFE_MODE:
145	pet_eud(chip);
146	return IRQ_HANDLED;
147	default:
148	return IRQ_NONE;
149	}
150	}
151
152	static irqreturn_t handle_eud_irq_thread(int irq, void *data)
153	{
154	struct eud_chip *chip = data;
155	int ret;
156
157	if (chip->usb_attached)
158	ret = usb_role_switch_set_role(chip->role_sw, USB_ROLE_DEVICE);
159	else
160	ret = usb_role_switch_set_role(chip->role_sw, USB_ROLE_HOST);
161	if (ret)
162	dev_err(chip->dev, "failed to set role switch\n");
163
164	/* set and clear vbus_int_clr[0] to clear interrupt */
165	writel(BIT(0), chip->base + EUD_REG_VBUS_INT_CLR);
166	writel(0, chip->base + EUD_REG_VBUS_INT_CLR);
167
168	return IRQ_HANDLED;
169	}
170
171	static void eud_role_switch_release(void *data)
172	{
173	struct eud_chip *chip = data;
174
175	usb_role_switch_put(chip->role_sw);
176	}
177
178	static int eud_probe(struct platform_device *pdev)
179	{
180	struct eud_chip *chip;
181	int ret;
182
183	chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
184	if (!chip)
185	return -ENOMEM;
186
187	chip->dev = &pdev->dev;
188
9a1bf58c SC	189	chip->role_sw = usb_role_switch_get(&pdev->dev);
	190	if (IS_ERR(chip->role_sw))
	191	return dev_err_probe(chip->dev, PTR_ERR(chip->role_sw),
	192	"failed to get role switch\n");
	193
929b22e6 CJ	194	ret = devm_add_action_or_reset(chip->dev, eud_role_switch_release, chip);
	195	if (ret)
	196	return dev_err_probe(chip->dev, ret,
	197	"failed to add role switch release action\n");
	198
9a1bf58c SC	199	chip->base = devm_platform_ioremap_resource(pdev, 0);
	200	if (IS_ERR(chip->base))
	201	return PTR_ERR(chip->base);
	202
	203	chip->mode_mgr = devm_platform_ioremap_resource(pdev, 1);
	204	if (IS_ERR(chip->mode_mgr))
	205	return PTR_ERR(chip->mode_mgr);
	206
	207	chip->irq = platform_get_irq(pdev, 0);
	208	ret = devm_request_threaded_irq(&pdev->dev, chip->irq, handle_eud_irq,
	209	handle_eud_irq_thread, IRQF_ONESHOT, NULL, chip);
	210	if (ret)
	211	return dev_err_probe(chip->dev, ret, "failed to allocate irq\n");
	212
	213	enable_irq_wake(chip->irq);
	214
	215	platform_set_drvdata(pdev, chip);
	216
	217	return 0;
	218	}
	219
	220	static int eud_remove(struct platform_device *pdev)
	221	{
	222	struct eud_chip *chip = platform_get_drvdata(pdev);
	223
	224	if (chip->enabled)
	225	disable_eud(chip);
	226
	227	device_init_wakeup(&pdev->dev, false);
	228	disable_irq_wake(chip->irq);
	229
	230	return 0;
	231	}
	232
	233	static const struct of_device_id eud_dt_match[] = {
	234	{ .compatible = "qcom,sc7280-eud" },
	235	{ }
	236	};
	237	MODULE_DEVICE_TABLE(of, eud_dt_match);
	238
	239	static struct platform_driver eud_driver = {
	240	.probe = eud_probe,
	241	.remove = eud_remove,
	242	.driver = {
	243	.name = "qcom_eud",
	244	.dev_groups = eud_groups,
	245	.of_match_table = eud_dt_match,
	246	},
	247	};
	248	module_platform_driver(eud_driver);
	249
	250	MODULE_DESCRIPTION("QTI EUD driver");
	251	MODULE_LICENSE("GPL v2");