[linux-2.6-block.git] / drivers / bus / bt1-apb.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2020 BAIKAL ELECTRONICS, JSC
 *
 * Authors:
 *   Serge Semin <Sergey.Semin@baikalelectronics.ru>
 *
 * Baikal-T1 APB-bus driver
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/device.h>
#include <linux/atomic.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/nmi.h>
#include <linux/of.h>
#include <linux/regmap.h>
#include <linux/clk.h>
#include <linux/reset.h>
#include <linux/time64.h>
#include <linux/clk.h>
#include <linux/sysfs.h>

#define APB_EHB_ISR			0x00
#define APB_EHB_ISR_PENDING		BIT(0)
#define APB_EHB_ISR_MASK		BIT(1)
#define APB_EHB_ADDR			0x04
#define APB_EHB_TIMEOUT			0x08

#define APB_EHB_TIMEOUT_MIN		0x000003FFU
#define APB_EHB_TIMEOUT_MAX		0xFFFFFFFFU

/*
 * struct bt1_apb - Baikal-T1 APB EHB private data
 * @dev: Pointer to the device structure.
 * @regs: APB EHB registers map.
 * @res: No-device error injection memory region.
 * @irq: Errors IRQ number.
 * @rate: APB-bus reference clock rate.
 * @pclk: APB-reference clock.
 * @prst: APB domain reset line.
 * @count: Number of errors detected.
 */
struct bt1_apb {
	struct device *dev;

	struct regmap *regs;
	void __iomem *res;
	int irq;

	unsigned long rate;
	struct clk *pclk;

	struct reset_control *prst;

	atomic_t count;
};

static const struct regmap_config bt1_apb_regmap_cfg = {
	.reg_bits = 32,
	.val_bits = 32,
	.reg_stride = 4,
	.max_register = APB_EHB_TIMEOUT,
	.fast_io = true
};

static inline unsigned long bt1_apb_n_to_timeout_us(struct bt1_apb *apb, u32 n)
{
	u64 timeout = (u64)n * USEC_PER_SEC;

	do_div(timeout, apb->rate);

	return timeout;

}

static inline unsigned long bt1_apb_timeout_to_n_us(struct bt1_apb *apb,
						    unsigned long timeout)
{
	u64 n = (u64)timeout * apb->rate;

	do_div(n, USEC_PER_SEC);

	return n;

}

static irqreturn_t bt1_apb_isr(int irq, void *data)
{
	struct bt1_apb *apb = data;
	u32 addr = 0;

	regmap_read(apb->regs, APB_EHB_ADDR, &addr);

	dev_crit_ratelimited(apb->dev,
		"APB-bus fault %d: Slave access timeout at 0x%08x\n",
		atomic_inc_return(&apb->count),
		addr);

	/*
	 * Print backtrace on each CPU. This might be pointless if the fault
	 * has happened on the same CPU as the IRQ handler is executed or
	 * the other core proceeded further execution despite the error.
	 * But if it's not, by looking at the trace we would get straight to
	 * the cause of the problem.
	 */
	trigger_all_cpu_backtrace();

	regmap_update_bits(apb->regs, APB_EHB_ISR, APB_EHB_ISR_PENDING, 0);

	return IRQ_HANDLED;
}

static void bt1_apb_clear_data(void *data)
{
	struct bt1_apb *apb = data;
	struct platform_device *pdev = to_platform_device(apb->dev);

	platform_set_drvdata(pdev, NULL);
}

static struct bt1_apb *bt1_apb_create_data(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct bt1_apb *apb;
	int ret;

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

	ret = devm_add_action(dev, bt1_apb_clear_data, apb);
	if (ret) {
		dev_err(dev, "Can't add APB EHB data clear action\n");
		return ERR_PTR(ret);
	}

	apb->dev = dev;
	atomic_set(&apb->count, 0);
	platform_set_drvdata(pdev, apb);

	return apb;
}

static int bt1_apb_request_regs(struct bt1_apb *apb)
{
	struct platform_device *pdev = to_platform_device(apb->dev);
	void __iomem *regs;

	regs = devm_platform_ioremap_resource_byname(pdev, "ehb");
	if (IS_ERR(regs)) {
		dev_err(apb->dev, "Couldn't map APB EHB registers\n");
		return PTR_ERR(regs);
	}

	apb->regs = devm_regmap_init_mmio(apb->dev, regs, &bt1_apb_regmap_cfg);
	if (IS_ERR(apb->regs)) {
		dev_err(apb->dev, "Couldn't create APB EHB regmap\n");
		return PTR_ERR(apb->regs);
	}

	apb->res = devm_platform_ioremap_resource_byname(pdev, "nodev");
	if (IS_ERR(apb->res))
		dev_err(apb->dev, "Couldn't map reserved region\n");

	return PTR_ERR_OR_ZERO(apb->res);
}

static int bt1_apb_request_rst(struct bt1_apb *apb)
{
	int ret;

	apb->prst = devm_reset_control_get_optional_exclusive(apb->dev, "prst");
	if (IS_ERR(apb->prst))
		return dev_err_probe(apb->dev, PTR_ERR(apb->prst),
				     "Couldn't get reset control line\n");

	ret = reset_control_deassert(apb->prst);
	if (ret)
		dev_err(apb->dev, "Failed to deassert the reset line\n");

	return ret;
}

static void bt1_apb_disable_clk(void *data)
{
	struct bt1_apb *apb = data;

	clk_disable_unprepare(apb->pclk);
}

static int bt1_apb_request_clk(struct bt1_apb *apb)
{
	int ret;

	apb->pclk = devm_clk_get(apb->dev, "pclk");
	if (IS_ERR(apb->pclk))
		return dev_err_probe(apb->dev, PTR_ERR(apb->pclk),
				     "Couldn't get APB clock descriptor\n");

	ret = clk_prepare_enable(apb->pclk);
	if (ret) {
		dev_err(apb->dev, "Couldn't enable the APB clock\n");
		return ret;
	}

	ret = devm_add_action_or_reset(apb->dev, bt1_apb_disable_clk, apb);
	if (ret) {
		dev_err(apb->dev, "Can't add APB EHB clocks disable action\n");
		return ret;
	}

	apb->rate = clk_get_rate(apb->pclk);
	if (!apb->rate) {
		dev_err(apb->dev, "Invalid clock rate\n");
		return -EINVAL;
	}

	return 0;
}

static void bt1_apb_clear_irq(void *data)
{
	struct bt1_apb *apb = data;

	regmap_update_bits(apb->regs, APB_EHB_ISR, APB_EHB_ISR_MASK, 0);
}

static int bt1_apb_request_irq(struct bt1_apb *apb)
{
	struct platform_device *pdev = to_platform_device(apb->dev);
	int ret;

	apb->irq = platform_get_irq(pdev, 0);
	if (apb->irq < 0)
		return apb->irq;

	ret = devm_request_irq(apb->dev, apb->irq, bt1_apb_isr, IRQF_SHARED,
			       "bt1-apb", apb);
	if (ret) {
		dev_err(apb->dev, "Couldn't request APB EHB IRQ\n");
		return ret;
	}

	ret = devm_add_action(apb->dev, bt1_apb_clear_irq, apb);
	if (ret) {
		dev_err(apb->dev, "Can't add APB EHB IRQs clear action\n");
		return ret;
	}

	/* Unmask IRQ and clear it' pending flag. */
	regmap_update_bits(apb->regs, APB_EHB_ISR,
			   APB_EHB_ISR_PENDING | APB_EHB_ISR_MASK,
			   APB_EHB_ISR_MASK);

	return 0;
}

static ssize_t count_show(struct device *dev, struct device_attribute *attr,
			  char *buf)
{
	struct bt1_apb *apb = dev_get_drvdata(dev);

	return scnprintf(buf, PAGE_SIZE, "%d\n", atomic_read(&apb->count));
}
static DEVICE_ATTR_RO(count);

static ssize_t timeout_show(struct device *dev, struct device_attribute *attr,
			    char *buf)
{
	struct bt1_apb *apb = dev_get_drvdata(dev);
	unsigned long timeout;
	int ret;
	u32 n;

	ret = regmap_read(apb->regs, APB_EHB_TIMEOUT, &n);
	if (ret)
		return ret;

	timeout = bt1_apb_n_to_timeout_us(apb, n);

	return scnprintf(buf, PAGE_SIZE, "%lu\n", timeout);
}

static ssize_t timeout_store(struct device *dev,
			     struct device_attribute *attr,
			     const char *buf, size_t count)
{
	struct bt1_apb *apb = dev_get_drvdata(dev);
	unsigned long timeout;
	int ret;
	u32 n;

	if (kstrtoul(buf, 0, &timeout) < 0)
		return -EINVAL;

	n = bt1_apb_timeout_to_n_us(apb, timeout);
	n = clamp(n, APB_EHB_TIMEOUT_MIN, APB_EHB_TIMEOUT_MAX);

	ret = regmap_write(apb->regs, APB_EHB_TIMEOUT, n);

	return ret ?: count;
}
static DEVICE_ATTR_RW(timeout);

static ssize_t inject_error_show(struct device *dev,
				 struct device_attribute *attr, char *buf)
{
	return scnprintf(buf, PAGE_SIZE, "Error injection: nodev irq\n");
}

static ssize_t inject_error_store(struct device *dev,
				  struct device_attribute *attr,
				  const char *data, size_t count)
{
	struct bt1_apb *apb = dev_get_drvdata(dev);

	/*
	 * Either dummy read from the unmapped address in the APB IO area
	 * or manually set the IRQ status.
	 */
	if (sysfs_streq(data, "nodev"))
		readl(apb->res);
	else if (sysfs_streq(data, "irq"))
		regmap_update_bits(apb->regs, APB_EHB_ISR, APB_EHB_ISR_PENDING,
				   APB_EHB_ISR_PENDING);
	else
		return -EINVAL;

	return count;
}
static DEVICE_ATTR_RW(inject_error);

static struct attribute *bt1_apb_sysfs_attrs[] = {
	&dev_attr_count.attr,
	&dev_attr_timeout.attr,
	&dev_attr_inject_error.attr,
	NULL
};
ATTRIBUTE_GROUPS(bt1_apb_sysfs);

static void bt1_apb_remove_sysfs(void *data)
{
	struct bt1_apb *apb = data;

	device_remove_groups(apb->dev, bt1_apb_sysfs_groups);
}

static int bt1_apb_init_sysfs(struct bt1_apb *apb)
{
	int ret;

	ret = device_add_groups(apb->dev, bt1_apb_sysfs_groups);
	if (ret) {
		dev_err(apb->dev, "Failed to create EHB APB sysfs nodes\n");
		return ret;
	}

	ret = devm_add_action_or_reset(apb->dev, bt1_apb_remove_sysfs, apb);
	if (ret)
		dev_err(apb->dev, "Can't add APB EHB sysfs remove action\n");

	return ret;
}

static int bt1_apb_probe(struct platform_device *pdev)
{
	struct bt1_apb *apb;
	int ret;

	apb = bt1_apb_create_data(pdev);
	if (IS_ERR(apb))
		return PTR_ERR(apb);

	ret = bt1_apb_request_regs(apb);
	if (ret)
		return ret;

	ret = bt1_apb_request_rst(apb);
	if (ret)
		return ret;

	ret = bt1_apb_request_clk(apb);
	if (ret)
		return ret;

	ret = bt1_apb_request_irq(apb);
	if (ret)
		return ret;

	ret = bt1_apb_init_sysfs(apb);
	if (ret)
		return ret;

	return 0;
}

static const struct of_device_id bt1_apb_of_match[] = {
	{ .compatible = "baikal,bt1-apb" },
	{ }
};
MODULE_DEVICE_TABLE(of, bt1_apb_of_match);

static struct platform_driver bt1_apb_driver = {
	.probe = bt1_apb_probe,
	.driver = {
		.name = "bt1-apb",
		.of_match_table = bt1_apb_of_match
	}
};
module_platform_driver(bt1_apb_driver);

MODULE_AUTHOR("Serge Semin <Sergey.Semin@baikalelectronics.ru>");
MODULE_DESCRIPTION("Baikal-T1 APB-bus driver");
Commit	Line	Data
8f93662d SS	1	// SPDX-License-Identifier: GPL-2.0-only
	2	/*
	3	* Copyright (C) 2020 BAIKAL ELECTRONICS, JSC
	4	*
	5	* Authors:
	6	* Serge Semin <Sergey.Semin@baikalelectronics.ru>
	7	*
	8	* Baikal-T1 APB-bus driver
	9	*/
	10
	11	#include <linux/kernel.h>
	12	#include <linux/module.h>
	13	#include <linux/types.h>
	14	#include <linux/device.h>
	15	#include <linux/atomic.h>
	16	#include <linux/platform_device.h>
	17	#include <linux/interrupt.h>
1c8ceb16	18	#include <linux/io.h>
8f93662d SS	19	#include <linux/nmi.h>
	20	#include <linux/of.h>
	21	#include <linux/regmap.h>
	22	#include <linux/clk.h>
	23	#include <linux/reset.h>
	24	#include <linux/time64.h>
	25	#include <linux/clk.h>
	26	#include <linux/sysfs.h>
	27
	28	#define APB_EHB_ISR 0x00
	29	#define APB_EHB_ISR_PENDING BIT(0)
	30	#define APB_EHB_ISR_MASK BIT(1)
	31	#define APB_EHB_ADDR 0x04
	32	#define APB_EHB_TIMEOUT 0x08
	33
	34	#define APB_EHB_TIMEOUT_MIN 0x000003FFU
	35	#define APB_EHB_TIMEOUT_MAX 0xFFFFFFFFU
	36
	37	/*
	38	* struct bt1_apb - Baikal-T1 APB EHB private data
	39	* @dev: Pointer to the device structure.
	40	* @regs: APB EHB registers map.
	41	* @res: No-device error injection memory region.
	42	* @irq: Errors IRQ number.
	43	* @rate: APB-bus reference clock rate.
	44	* @pclk: APB-reference clock.
	45	* @prst: APB domain reset line.
	46	* @count: Number of errors detected.
	47	*/
	48	struct bt1_apb {
	49	struct device *dev;
	50
	51	struct regmap *regs;
	52	void __iomem *res;
	53	int irq;
	54
	55	unsigned long rate;
	56	struct clk *pclk;
	57
	58	struct reset_control *prst;
	59
	60	atomic_t count;
	61	};
	62
	63	static const struct regmap_config bt1_apb_regmap_cfg = {
	64	.reg_bits = 32,
	65	.val_bits = 32,
	66	.reg_stride = 4,
	67	.max_register = APB_EHB_TIMEOUT,
	68	.fast_io = true
	69	};
	70
	71	static inline unsigned long bt1_apb_n_to_timeout_us(struct bt1_apb *apb, u32 n)
	72	{
	73	u64 timeout = (u64)n * USEC_PER_SEC;
	74
	75	do_div(timeout, apb->rate);
	76
	77	return timeout;
	78
	79	}
	80
	81	static inline unsigned long bt1_apb_timeout_to_n_us(struct bt1_apb *apb,
	82	unsigned long timeout)
83	{
84	u64 n = (u64)timeout * apb->rate;
85
86	do_div(n, USEC_PER_SEC);
87
88	return n;
89
90	}
91
92	static irqreturn_t bt1_apb_isr(int irq, void *data)
93	{
94	struct bt1_apb *apb = data;
95	u32 addr = 0;
96
97	regmap_read(apb->regs, APB_EHB_ADDR, &addr);
98
99	dev_crit_ratelimited(apb->dev,
100	"APB-bus fault %d: Slave access timeout at 0x%08x\n",
101	atomic_inc_return(&apb->count),
102	addr);
103
104	/*
105	* Print backtrace on each CPU. This might be pointless if the fault
106	* has happened on the same CPU as the IRQ handler is executed or
107	* the other core proceeded further execution despite the error.
108	* But if it's not, by looking at the trace we would get straight to
109	* the cause of the problem.
110	*/
111	trigger_all_cpu_backtrace();
112
113	regmap_update_bits(apb->regs, APB_EHB_ISR, APB_EHB_ISR_PENDING, 0);
114
115	return IRQ_HANDLED;
116	}
117
118	static void bt1_apb_clear_data(void *data)
119	{
120	struct bt1_apb *apb = data;
121	struct platform_device *pdev = to_platform_device(apb->dev);
122
123	platform_set_drvdata(pdev, NULL);
124	}
125
126	static struct bt1_apb bt1_apb_create_data(struct platform_device pdev)
127	{
128	struct device *dev = &pdev->dev;
129	struct bt1_apb *apb;
130	int ret;
131
132	apb = devm_kzalloc(dev, sizeof(*apb), GFP_KERNEL);
133	if (!apb)
134	return ERR_PTR(-ENOMEM);
135
136	ret = devm_add_action(dev, bt1_apb_clear_data, apb);
137	if (ret) {
138	dev_err(dev, "Can't add APB EHB data clear action\n");
139	return ERR_PTR(ret);
140	}
141
142	apb->dev = dev;
143	atomic_set(&apb->count, 0);
144	platform_set_drvdata(pdev, apb);
145
146	return apb;
147	}
148
149	static int bt1_apb_request_regs(struct bt1_apb *apb)
150	{
151	struct platform_device *pdev = to_platform_device(apb->dev);
152	void __iomem *regs;
153
154	regs = devm_platform_ioremap_resource_byname(pdev, "ehb");
155	if (IS_ERR(regs)) {
156	dev_err(apb->dev, "Couldn't map APB EHB registers\n");
157	return PTR_ERR(regs);
158	}
159
160	apb->regs = devm_regmap_init_mmio(apb->dev, regs, &bt1_apb_regmap_cfg);
161	if (IS_ERR(apb->regs)) {
162	dev_err(apb->dev, "Couldn't create APB EHB regmap\n");
163	return PTR_ERR(apb->regs);
164	}
165
166	apb->res = devm_platform_ioremap_resource_byname(pdev, "nodev");
75341b3d	167	if (IS_ERR(apb->res))
8f93662d	168	dev_err(apb->dev, "Couldn't map reserved region\n");
8f93662d	169
75341b3d	170	return PTR_ERR_OR_ZERO(apb->res);
8f93662d SS	171	}
	172
	173	static int bt1_apb_request_rst(struct bt1_apb *apb)
	174	{
	175	int ret;
	176
	177	apb->prst = devm_reset_control_get_optional_exclusive(apb->dev, "prst");
be5cddef SS	178	if (IS_ERR(apb->prst))
	179	return dev_err_probe(apb->dev, PTR_ERR(apb->prst),
	180	"Couldn't get reset control line\n");
8f93662d SS	181
	182	ret = reset_control_deassert(apb->prst);
	183	if (ret)
	184	dev_err(apb->dev, "Failed to deassert the reset line\n");
	185
	186	return ret;
	187	}
	188
	189	static void bt1_apb_disable_clk(void *data)
	190	{
	191	struct bt1_apb *apb = data;
	192
	193	clk_disable_unprepare(apb->pclk);
	194	}
	195
	196	static int bt1_apb_request_clk(struct bt1_apb *apb)
	197	{
	198	int ret;
	199
	200	apb->pclk = devm_clk_get(apb->dev, "pclk");
be5cddef SS	201	if (IS_ERR(apb->pclk))
	202	return dev_err_probe(apb->dev, PTR_ERR(apb->pclk),
	203	"Couldn't get APB clock descriptor\n");
8f93662d SS	204
	205	ret = clk_prepare_enable(apb->pclk);
	206	if (ret) {
	207	dev_err(apb->dev, "Couldn't enable the APB clock\n");
	208	return ret;
	209	}
	210
	211	ret = devm_add_action_or_reset(apb->dev, bt1_apb_disable_clk, apb);
	212	if (ret) {
	213	dev_err(apb->dev, "Can't add APB EHB clocks disable action\n");
	214	return ret;
	215	}
	216
	217	apb->rate = clk_get_rate(apb->pclk);
	218	if (!apb->rate) {
	219	dev_err(apb->dev, "Invalid clock rate\n");
	220	return -EINVAL;
	221	}
	222
	223	return 0;
	224	}
	225
	226	static void bt1_apb_clear_irq(void *data)
	227	{
	228	struct bt1_apb *apb = data;
	229
	230	regmap_update_bits(apb->regs, APB_EHB_ISR, APB_EHB_ISR_MASK, 0);
	231	}
	232
	233	static int bt1_apb_request_irq(struct bt1_apb *apb)
	234	{
	235	struct platform_device *pdev = to_platform_device(apb->dev);
	236	int ret;
	237
	238	apb->irq = platform_get_irq(pdev, 0);
	239	if (apb->irq < 0)
	240	return apb->irq;
	241
	242	ret = devm_request_irq(apb->dev, apb->irq, bt1_apb_isr, IRQF_SHARED,
	243	"bt1-apb", apb);
	244	if (ret) {
	245	dev_err(apb->dev, "Couldn't request APB EHB IRQ\n");
	246	return ret;
	247	}
	248
	249	ret = devm_add_action(apb->dev, bt1_apb_clear_irq, apb);
	250	if (ret) {
	251	dev_err(apb->dev, "Can't add APB EHB IRQs clear action\n");
	252	return ret;
	253	}
	254
	255	/* Unmask IRQ and clear it' pending flag. */
	256	regmap_update_bits(apb->regs, APB_EHB_ISR,
	257	APB_EHB_ISR_PENDING \| APB_EHB_ISR_MASK,
	258	APB_EHB_ISR_MASK);
	259
	260	return 0;
	261	}
	262
	263	static ssize_t count_show(struct device dev, struct device_attribute attr,
	264	char *buf)
	265	{
	266	struct bt1_apb *apb = dev_get_drvdata(dev);
	267
268	return scnprintf(buf, PAGE_SIZE, "%d\n", atomic_read(&apb->count));
269	}
270	static DEVICE_ATTR_RO(count);
271
272	static ssize_t timeout_show(struct device dev, struct device_attribute attr,
273	char *buf)
274	{
275	struct bt1_apb *apb = dev_get_drvdata(dev);
276	unsigned long timeout;
277	int ret;
278	u32 n;
279
280	ret = regmap_read(apb->regs, APB_EHB_TIMEOUT, &n);
281	if (ret)
282	return ret;
283
284	timeout = bt1_apb_n_to_timeout_us(apb, n);
285
286	return scnprintf(buf, PAGE_SIZE, "%lu\n", timeout);
287	}
288
289	static ssize_t timeout_store(struct device *dev,
290	struct device_attribute *attr,
291	const char *buf, size_t count)
292	{
293	struct bt1_apb *apb = dev_get_drvdata(dev);
294	unsigned long timeout;
295	int ret;
296	u32 n;
297
298	if (kstrtoul(buf, 0, &timeout) < 0)
299	return -EINVAL;
300
301	n = bt1_apb_timeout_to_n_us(apb, timeout);
302	n = clamp(n, APB_EHB_TIMEOUT_MIN, APB_EHB_TIMEOUT_MAX);
303
304	ret = regmap_write(apb->regs, APB_EHB_TIMEOUT, n);
305
306	return ret ?: count;
307	}
308	static DEVICE_ATTR_RW(timeout);
309
b19dc1b7 SS	310	static ssize_t inject_error_show(struct device *dev,
b19dc1b7 SS	311	struct device_attribute attr, char buf)
8f93662d SS	312	{
	313	return scnprintf(buf, PAGE_SIZE, "Error injection: nodev irq\n");
	314	}
	315
	316	static ssize_t inject_error_store(struct device *dev,
b19dc1b7 SS	317	struct device_attribute *attr,
b19dc1b7 SS	318	const char *data, size_t count)
8f93662d SS	319	{
	320	struct bt1_apb *apb = dev_get_drvdata(dev);
	321
	322	/*
	323	* Either dummy read from the unmapped address in the APB IO area
	324	* or manually set the IRQ status.
	325	*/
b7cb430d	326	if (sysfs_streq(data, "nodev"))
8f93662d	327	readl(apb->res);
b7cb430d	328	else if (sysfs_streq(data, "irq"))
8f93662d SS	329	regmap_update_bits(apb->regs, APB_EHB_ISR, APB_EHB_ISR_PENDING,
	330	APB_EHB_ISR_PENDING);
	331	else
	332	return -EINVAL;
	333
	334	return count;
	335	}
	336	static DEVICE_ATTR_RW(inject_error);
	337
	338	static struct attribute *bt1_apb_sysfs_attrs[] = {
	339	&dev_attr_count.attr,
	340	&dev_attr_timeout.attr,
	341	&dev_attr_inject_error.attr,
	342	NULL
	343	};
	344	ATTRIBUTE_GROUPS(bt1_apb_sysfs);
	345
	346	static void bt1_apb_remove_sysfs(void *data)
	347	{
	348	struct bt1_apb *apb = data;
	349
	350	device_remove_groups(apb->dev, bt1_apb_sysfs_groups);
	351	}
	352
	353	static int bt1_apb_init_sysfs(struct bt1_apb *apb)
	354	{
	355	int ret;
	356
	357	ret = device_add_groups(apb->dev, bt1_apb_sysfs_groups);
	358	if (ret) {
	359	dev_err(apb->dev, "Failed to create EHB APB sysfs nodes\n");
	360	return ret;
	361	}
	362
	363	ret = devm_add_action_or_reset(apb->dev, bt1_apb_remove_sysfs, apb);
	364	if (ret)
	365	dev_err(apb->dev, "Can't add APB EHB sysfs remove action\n");
	366
	367	return ret;
	368	}
	369
	370	static int bt1_apb_probe(struct platform_device *pdev)
	371	{
	372	struct bt1_apb *apb;
	373	int ret;
	374
	375	apb = bt1_apb_create_data(pdev);
	376	if (IS_ERR(apb))
	377	return PTR_ERR(apb);
	378
	379	ret = bt1_apb_request_regs(apb);
	380	if (ret)
	381	return ret;
	382
	383	ret = bt1_apb_request_rst(apb);
	384	if (ret)
	385	return ret;
	386
	387	ret = bt1_apb_request_clk(apb);
	388	if (ret)
	389	return ret;
	390
	391	ret = bt1_apb_request_irq(apb);
	392	if (ret)
393	return ret;
394
395	ret = bt1_apb_init_sysfs(apb);
396	if (ret)
397	return ret;
398
399	return 0;
400	}
401
402	static const struct of_device_id bt1_apb_of_match[] = {
403	{ .compatible = "baikal,bt1-apb" },
404	{ }
405	};
406	MODULE_DEVICE_TABLE(of, bt1_apb_of_match);
407
408	static struct platform_driver bt1_apb_driver = {
409	.probe = bt1_apb_probe,
410	.driver = {
411	.name = "bt1-apb",
412	.of_match_table = bt1_apb_of_match
413	}
414	};
415	module_platform_driver(bt1_apb_driver);
416
417	MODULE_AUTHOR("Serge Semin <Sergey.Semin@baikalelectronics.ru>");
418	MODULE_DESCRIPTION("Baikal-T1 APB-bus driver");