[linux-block.git] / drivers / mfd / rsmu_spi.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * SPI driver for Renesas Synchronization Management Unit (SMU) devices.
 *
 * Copyright (C) 2021 Integrated Device Technology, Inc., a Renesas Company.
 */

#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/mfd/core.h>
#include <linux/mfd/rsmu.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/regmap.h>
#include <linux/slab.h>
#include <linux/spi/spi.h>

#include "rsmu.h"

#define	RSMU_CM_PAGE_ADDR		0x7C
#define	RSMU_SABRE_PAGE_ADDR		0x7F
#define	RSMU_HIGHER_ADDR_MASK		0xFF80
#define	RSMU_HIGHER_ADDR_SHIFT		7
#define	RSMU_LOWER_ADDR_MASK		0x7F

static int rsmu_read_device(struct rsmu_ddata *rsmu, u8 reg, u8 *buf, u16 bytes)
{
	struct spi_device *client = to_spi_device(rsmu->dev);
	struct spi_transfer xfer = {0};
	struct spi_message msg;
	u8 cmd[256] = {0};
	u8 rsp[256] = {0};
	int ret;

	cmd[0] = reg | 0x80;
	xfer.rx_buf = rsp;
	xfer.len = bytes + 1;
	xfer.tx_buf = cmd;
	xfer.bits_per_word = client->bits_per_word;
	xfer.speed_hz = client->max_speed_hz;

	spi_message_init(&msg);
	spi_message_add_tail(&xfer, &msg);

	/*
	 * 4-wire SPI is a shift register, so for every byte you send,
	 * you get one back at the same time. Example read from 0xC024,
	 * which has value of 0x2D
	 *
	 * MOSI:
	 *       7C 00 C0 #Set page register
	 *       A4 00    #MSB is set, so this is read command
	 * MISO:
	 *       XX 2D    #XX is a dummy byte from sending A4 and we
	 *                 need to throw it away
	 */
	ret = spi_sync(client, &msg);
	if (ret >= 0)
		memcpy(buf, &rsp[1], xfer.len-1);

	return ret;
}

static int rsmu_write_device(struct rsmu_ddata *rsmu, u8 reg, u8 *buf, u16 bytes)
{
	struct spi_device *client = to_spi_device(rsmu->dev);
	struct spi_transfer xfer = {0};
	struct spi_message msg;
	u8 cmd[256] = {0};

	cmd[0] = reg;
	memcpy(&cmd[1], buf, bytes);

	xfer.len = bytes + 1;
	xfer.tx_buf = cmd;
	xfer.bits_per_word = client->bits_per_word;
	xfer.speed_hz = client->max_speed_hz;
	spi_message_init(&msg);
	spi_message_add_tail(&xfer, &msg);

	return  spi_sync(client, &msg);
}

/*
 * 1-byte (1B) offset addressing:
 * 16-bit register address: the lower 7 bits of the register address come
 * from the offset addr byte and the upper 9 bits come from the page register.
 */
static int rsmu_write_page_register(struct rsmu_ddata *rsmu, u16 reg)
{
	u8 page_reg;
	u8 buf[2];
	u16 bytes;
	u16 page;
	int err;

	switch (rsmu->type) {
	case RSMU_CM:
		page_reg = RSMU_CM_PAGE_ADDR;
		page = reg & RSMU_HIGHER_ADDR_MASK;
		buf[0] = (u8)(page & 0xff);
		buf[1] = (u8)((page >> 8) & 0xff);
		bytes = 2;
		break;
	case RSMU_SABRE:
		page_reg = RSMU_SABRE_PAGE_ADDR;
		page = reg >> RSMU_HIGHER_ADDR_SHIFT;
		buf[0] = (u8)(page & 0xff);
		bytes = 1;
		break;
	default:
		dev_err(rsmu->dev, "Unsupported RSMU device type: %d\n", rsmu->type);
		return -ENODEV;
	}

	/* Simply return if we are on the same page */
	if (rsmu->page == page)
		return 0;

	err = rsmu_write_device(rsmu, page_reg, buf, bytes);
	if (err)
		dev_err(rsmu->dev, "Failed to set page offset 0x%x\n", page);
	else
		/* Remember the last page */
		rsmu->page = page;

	return err;
}

static int rsmu_reg_read(void *context, unsigned int reg, unsigned int *val)
{
	struct rsmu_ddata *rsmu = spi_get_drvdata((struct spi_device *)context);
	u8 addr = (u8)(reg & RSMU_LOWER_ADDR_MASK);
	int err;

	err = rsmu_write_page_register(rsmu, reg);
	if (err)
		return err;

	err = rsmu_read_device(rsmu, addr, (u8 *)val, 1);
	if (err)
		dev_err(rsmu->dev, "Failed to read offset address 0x%x\n", addr);

	return err;
}

static int rsmu_reg_write(void *context, unsigned int reg, unsigned int val)
{
	struct rsmu_ddata *rsmu = spi_get_drvdata((struct spi_device *)context);
	u8 addr = (u8)(reg & RSMU_LOWER_ADDR_MASK);
	u8 data = (u8)val;
	int err;

	err = rsmu_write_page_register(rsmu, reg);
	if (err)
		return err;

	err = rsmu_write_device(rsmu, addr, &data, 1);
	if (err)
		dev_err(rsmu->dev,
			"Failed to write offset address 0x%x\n", addr);

	return err;
}

static const struct regmap_config rsmu_cm_regmap_config = {
	.reg_bits = 16,
	.val_bits = 8,
	.max_register = 0xD000,
	.reg_read = rsmu_reg_read,
	.reg_write = rsmu_reg_write,
	.cache_type = REGCACHE_NONE,
};

static const struct regmap_config rsmu_sabre_regmap_config = {
	.reg_bits = 16,
	.val_bits = 8,
	.max_register = 0x400,
	.reg_read = rsmu_reg_read,
	.reg_write = rsmu_reg_write,
	.cache_type = REGCACHE_NONE,
};

static int rsmu_spi_probe(struct spi_device *client)
{
	const struct spi_device_id *id = spi_get_device_id(client);
	const struct regmap_config *cfg;
	struct rsmu_ddata *rsmu;
	int ret;

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

	spi_set_drvdata(client, rsmu);

	rsmu->dev = &client->dev;
	rsmu->type = (enum rsmu_type)id->driver_data;

	/* Initialize regmap */
	switch (rsmu->type) {
	case RSMU_CM:
		cfg = &rsmu_cm_regmap_config;
		break;
	case RSMU_SABRE:
		cfg = &rsmu_sabre_regmap_config;
		break;
	default:
		dev_err(rsmu->dev, "Unsupported RSMU device type: %d\n", rsmu->type);
		return -ENODEV;
	}

	rsmu->regmap = devm_regmap_init(&client->dev, NULL, client, cfg);
	if (IS_ERR(rsmu->regmap)) {
		ret = PTR_ERR(rsmu->regmap);
		dev_err(rsmu->dev, "Failed to allocate register map: %d\n", ret);
		return ret;
	}

	return rsmu_core_init(rsmu);
}

static void rsmu_spi_remove(struct spi_device *client)
{
	struct rsmu_ddata *rsmu = spi_get_drvdata(client);

	rsmu_core_exit(rsmu);
}

static const struct spi_device_id rsmu_spi_id[] = {
	{ "8a34000",  RSMU_CM },
	{ "8a34001",  RSMU_CM },
	{ "82p33810", RSMU_SABRE },
	{ "82p33811", RSMU_SABRE },
	{}
};
MODULE_DEVICE_TABLE(spi, rsmu_spi_id);

static const struct of_device_id rsmu_spi_of_match[] = {
	{ .compatible = "idt,8a34000",  .data = (void *)RSMU_CM },
	{ .compatible = "idt,8a34001",  .data = (void *)RSMU_CM },
	{ .compatible = "idt,82p33810", .data = (void *)RSMU_SABRE },
	{ .compatible = "idt,82p33811", .data = (void *)RSMU_SABRE },
	{}
};
MODULE_DEVICE_TABLE(of, rsmu_spi_of_match);

static struct spi_driver rsmu_spi_driver = {
	.driver = {
		.name = "rsmu-spi",
		.of_match_table = of_match_ptr(rsmu_spi_of_match),
	},
	.probe = rsmu_spi_probe,
	.remove	= rsmu_spi_remove,
	.id_table = rsmu_spi_id,
};

static int __init rsmu_spi_init(void)
{
	return spi_register_driver(&rsmu_spi_driver);
}
subsys_initcall(rsmu_spi_init);

static void __exit rsmu_spi_exit(void)
{
	spi_unregister_driver(&rsmu_spi_driver);
}
module_exit(rsmu_spi_exit);

MODULE_DESCRIPTION("Renesas SMU SPI driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
a1867f85 ML	1	// SPDX-License-Identifier: GPL-2.0+
	2	/*
	3	* SPI driver for Renesas Synchronization Management Unit (SMU) devices.
	4	*
	5	* Copyright (C) 2021 Integrated Device Technology, Inc., a Renesas Company.
	6	*/
	7
	8	#include <linux/init.h>
	9	#include <linux/kernel.h>
	10	#include <linux/mfd/core.h>
	11	#include <linux/mfd/rsmu.h>
	12	#include <linux/module.h>
	13	#include <linux/of.h>
	14	#include <linux/regmap.h>
	15	#include <linux/slab.h>
	16	#include <linux/spi/spi.h>
	17
	18	#include "rsmu.h"
	19
	20	#define RSMU_CM_PAGE_ADDR 0x7C
	21	#define RSMU_SABRE_PAGE_ADDR 0x7F
	22	#define RSMU_HIGHER_ADDR_MASK 0xFF80
	23	#define RSMU_HIGHER_ADDR_SHIFT 7
	24	#define RSMU_LOWER_ADDR_MASK 0x7F
	25
	26	static int rsmu_read_device(struct rsmu_ddata rsmu, u8 reg, u8 buf, u16 bytes)
	27	{
	28	struct spi_device *client = to_spi_device(rsmu->dev);
	29	struct spi_transfer xfer = {0};
	30	struct spi_message msg;
	31	u8 cmd[256] = {0};
	32	u8 rsp[256] = {0};
	33	int ret;
	34
	35	cmd[0] = reg \| 0x80;
	36	xfer.rx_buf = rsp;
	37	xfer.len = bytes + 1;
	38	xfer.tx_buf = cmd;
	39	xfer.bits_per_word = client->bits_per_word;
	40	xfer.speed_hz = client->max_speed_hz;
	41
	42	spi_message_init(&msg);
	43	spi_message_add_tail(&xfer, &msg);
	44
	45	/*
	46	* 4-wire SPI is a shift register, so for every byte you send,
	47	* you get one back at the same time. Example read from 0xC024,
	48	* which has value of 0x2D
	49	*
	50	* MOSI:
	51	* 7C 00 C0 #Set page register
	52	* A4 00 #MSB is set, so this is read command
	53	* MISO:
	54	* XX 2D #XX is a dummy byte from sending A4 and we
	55	* need to throw it away
	56	*/
	57	ret = spi_sync(client, &msg);
	58	if (ret >= 0)
	59	memcpy(buf, &rsp[1], xfer.len-1);
	60
	61	return ret;
	62	}
	63
	64	static int rsmu_write_device(struct rsmu_ddata rsmu, u8 reg, u8 buf, u16 bytes)
65	{
66	struct spi_device *client = to_spi_device(rsmu->dev);
67	struct spi_transfer xfer = {0};
68	struct spi_message msg;
69	u8 cmd[256] = {0};
70
71	cmd[0] = reg;
72	memcpy(&cmd[1], buf, bytes);
73
74	xfer.len = bytes + 1;
75	xfer.tx_buf = cmd;
76	xfer.bits_per_word = client->bits_per_word;
77	xfer.speed_hz = client->max_speed_hz;
78	spi_message_init(&msg);
79	spi_message_add_tail(&xfer, &msg);
80
81	return spi_sync(client, &msg);
82	}
83
84	/*
85	* 1-byte (1B) offset addressing:
86	* 16-bit register address: the lower 7 bits of the register address come
87	* from the offset addr byte and the upper 9 bits come from the page register.
88	*/
89	static int rsmu_write_page_register(struct rsmu_ddata *rsmu, u16 reg)
90	{
91	u8 page_reg;
92	u8 buf[2];
93	u16 bytes;
94	u16 page;
95	int err;
96
97	switch (rsmu->type) {
98	case RSMU_CM:
99	page_reg = RSMU_CM_PAGE_ADDR;
100	page = reg & RSMU_HIGHER_ADDR_MASK;
101	buf[0] = (u8)(page & 0xff);
102	buf[1] = (u8)((page >> 8) & 0xff);
103	bytes = 2;
104	break;
105	case RSMU_SABRE:
106	page_reg = RSMU_SABRE_PAGE_ADDR;
107	page = reg >> RSMU_HIGHER_ADDR_SHIFT;
108	buf[0] = (u8)(page & 0xff);
109	bytes = 1;
110	break;
111	default:
112	dev_err(rsmu->dev, "Unsupported RSMU device type: %d\n", rsmu->type);
113	return -ENODEV;
114	}
115
116	/* Simply return if we are on the same page */
117	if (rsmu->page == page)
118	return 0;
119
120	err = rsmu_write_device(rsmu, page_reg, buf, bytes);
121	if (err)
122	dev_err(rsmu->dev, "Failed to set page offset 0x%x\n", page);
123	else
124	/* Remember the last page */
125	rsmu->page = page;
126
127	return err;
128	}
129
130	static int rsmu_reg_read(void context, unsigned int reg, unsigned int val)
131	{
132	struct rsmu_ddata rsmu = spi_get_drvdata((struct spi_device )context);
133	u8 addr = (u8)(reg & RSMU_LOWER_ADDR_MASK);
134	int err;
135
136	err = rsmu_write_page_register(rsmu, reg);
137	if (err)
138	return err;
139
140	err = rsmu_read_device(rsmu, addr, (u8 *)val, 1);
141	if (err)
142	dev_err(rsmu->dev, "Failed to read offset address 0x%x\n", addr);
143
144	return err;
145	}
146
147	static int rsmu_reg_write(void *context, unsigned int reg, unsigned int val)
148	{
149	struct rsmu_ddata rsmu = spi_get_drvdata((struct spi_device )context);
150	u8 addr = (u8)(reg & RSMU_LOWER_ADDR_MASK);
151	u8 data = (u8)val;
152	int err;
153
154	err = rsmu_write_page_register(rsmu, reg);
155	if (err)
156	return err;
157
158	err = rsmu_write_device(rsmu, addr, &data, 1);
159	if (err)
160	dev_err(rsmu->dev,
161	"Failed to write offset address 0x%x\n", addr);
162
163	return err;
164	}
165
166	static const struct regmap_config rsmu_cm_regmap_config = {
167	.reg_bits = 16,
168	.val_bits = 8,
169	.max_register = 0xD000,
170	.reg_read = rsmu_reg_read,
171	.reg_write = rsmu_reg_write,
172	.cache_type = REGCACHE_NONE,
173	};
174
175	static const struct regmap_config rsmu_sabre_regmap_config = {
176	.reg_bits = 16,
177	.val_bits = 8,
178	.max_register = 0x400,
179	.reg_read = rsmu_reg_read,
180	.reg_write = rsmu_reg_write,
181	.cache_type = REGCACHE_NONE,
182	};
183
184	static int rsmu_spi_probe(struct spi_device *client)
185	{
186	const struct spi_device_id *id = spi_get_device_id(client);
187	const struct regmap_config *cfg;
188	struct rsmu_ddata *rsmu;
189	int ret;
190
191	rsmu = devm_kzalloc(&client->dev, sizeof(*rsmu), GFP_KERNEL);
192	if (!rsmu)
193	return -ENOMEM;
194
195	spi_set_drvdata(client, rsmu);
196
197	rsmu->dev = &client->dev;
198	rsmu->type = (enum rsmu_type)id->driver_data;
199
200	/* Initialize regmap */
201	switch (rsmu->type) {
202	case RSMU_CM:
203	cfg = &rsmu_cm_regmap_config;
204	break;
205	case RSMU_SABRE:
206	cfg = &rsmu_sabre_regmap_config;
207	break;
208	default:
209	dev_err(rsmu->dev, "Unsupported RSMU device type: %d\n", rsmu->type);
210	return -ENODEV;
211	}
212
213	rsmu->regmap = devm_regmap_init(&client->dev, NULL, client, cfg);
214	if (IS_ERR(rsmu->regmap)) {
215	ret = PTR_ERR(rsmu->regmap);
216	dev_err(rsmu->dev, "Failed to allocate register map: %d\n", ret);
217	return ret;
218	}
219
220	return rsmu_core_init(rsmu);
221	}
222
a0386bba	223	static void rsmu_spi_remove(struct spi_device *client)
a1867f85 ML	224	{
	225	struct rsmu_ddata *rsmu = spi_get_drvdata(client);
	226
	227	rsmu_core_exit(rsmu);
a1867f85 ML	228	}
	229
	230	static const struct spi_device_id rsmu_spi_id[] = {
	231	{ "8a34000", RSMU_CM },
	232	{ "8a34001", RSMU_CM },
	233	{ "82p33810", RSMU_SABRE },
	234	{ "82p33811", RSMU_SABRE },
	235	{}
	236	};
	237	MODULE_DEVICE_TABLE(spi, rsmu_spi_id);
	238
	239	static const struct of_device_id rsmu_spi_of_match[] = {
	240	{ .compatible = "idt,8a34000", .data = (void *)RSMU_CM },
	241	{ .compatible = "idt,8a34001", .data = (void *)RSMU_CM },
	242	{ .compatible = "idt,82p33810", .data = (void *)RSMU_SABRE },
	243	{ .compatible = "idt,82p33811", .data = (void *)RSMU_SABRE },
	244	{}
	245	};
	246	MODULE_DEVICE_TABLE(of, rsmu_spi_of_match);
	247
	248	static struct spi_driver rsmu_spi_driver = {
	249	.driver = {
	250	.name = "rsmu-spi",
	251	.of_match_table = of_match_ptr(rsmu_spi_of_match),
	252	},
	253	.probe = rsmu_spi_probe,
	254	.remove = rsmu_spi_remove,
	255	.id_table = rsmu_spi_id,
	256	};
	257
	258	static int __init rsmu_spi_init(void)
	259	{
	260	return spi_register_driver(&rsmu_spi_driver);
	261	}
	262	subsys_initcall(rsmu_spi_init);
	263
	264	static void __exit rsmu_spi_exit(void)
	265	{
	266	spi_unregister_driver(&rsmu_spi_driver);
	267	}
	268	module_exit(rsmu_spi_exit);
	269
	270	MODULE_DESCRIPTION("Renesas SMU SPI driver");
	271	MODULE_LICENSE("GPL");