[mirror_ubuntu-bionic-kernel.git] / drivers / net / phy / spi_ks8995.c

/*
 * SPI driver for Micrel/Kendin KS8995M and KSZ8864RMN ethernet switches
 *
 * Copyright (C) 2008 Gabor Juhos <juhosg at openwrt.org>
 *
 * This file was based on: drivers/spi/at25.c
 *     Copyright (C) 2006 David Brownell
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published
 * by the Free Software Foundation.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/gpio/consumer.h>
#include <linux/of.h>
#include <linux/of_gpio.h>

#include <linux/spi/spi.h>

#define DRV_VERSION		"0.1.1"
#define DRV_DESC		"Micrel KS8995 Ethernet switch SPI driver"

/* ------------------------------------------------------------------------ */

#define KS8995_REG_ID0		0x00    /* Chip ID0 */
#define KS8995_REG_ID1		0x01    /* Chip ID1 */

#define KS8995_REG_GC0		0x02    /* Global Control 0 */
#define KS8995_REG_GC1		0x03    /* Global Control 1 */
#define KS8995_REG_GC2		0x04    /* Global Control 2 */
#define KS8995_REG_GC3		0x05    /* Global Control 3 */
#define KS8995_REG_GC4		0x06    /* Global Control 4 */
#define KS8995_REG_GC5		0x07    /* Global Control 5 */
#define KS8995_REG_GC6		0x08    /* Global Control 6 */
#define KS8995_REG_GC7		0x09    /* Global Control 7 */
#define KS8995_REG_GC8		0x0a    /* Global Control 8 */
#define KS8995_REG_GC9		0x0b    /* Global Control 9 */

#define KS8995_REG_PC(p, r)	((0x10 * p) + r)	 /* Port Control */
#define KS8995_REG_PS(p, r)	((0x10 * p) + r + 0xe)  /* Port Status */

#define KS8995_REG_TPC0		0x60    /* TOS Priority Control 0 */
#define KS8995_REG_TPC1		0x61    /* TOS Priority Control 1 */
#define KS8995_REG_TPC2		0x62    /* TOS Priority Control 2 */
#define KS8995_REG_TPC3		0x63    /* TOS Priority Control 3 */
#define KS8995_REG_TPC4		0x64    /* TOS Priority Control 4 */
#define KS8995_REG_TPC5		0x65    /* TOS Priority Control 5 */
#define KS8995_REG_TPC6		0x66    /* TOS Priority Control 6 */
#define KS8995_REG_TPC7		0x67    /* TOS Priority Control 7 */

#define KS8995_REG_MAC0		0x68    /* MAC address 0 */
#define KS8995_REG_MAC1		0x69    /* MAC address 1 */
#define KS8995_REG_MAC2		0x6a    /* MAC address 2 */
#define KS8995_REG_MAC3		0x6b    /* MAC address 3 */
#define KS8995_REG_MAC4		0x6c    /* MAC address 4 */
#define KS8995_REG_MAC5		0x6d    /* MAC address 5 */

#define KS8995_REG_IAC0		0x6e    /* Indirect Access Control 0 */
#define KS8995_REG_IAC1		0x6f    /* Indirect Access Control 0 */
#define KS8995_REG_IAD7		0x70    /* Indirect Access Data 7 */
#define KS8995_REG_IAD6		0x71    /* Indirect Access Data 6 */
#define KS8995_REG_IAD5		0x72    /* Indirect Access Data 5 */
#define KS8995_REG_IAD4		0x73    /* Indirect Access Data 4 */
#define KS8995_REG_IAD3		0x74    /* Indirect Access Data 3 */
#define KS8995_REG_IAD2		0x75    /* Indirect Access Data 2 */
#define KS8995_REG_IAD1		0x76    /* Indirect Access Data 1 */
#define KS8995_REG_IAD0		0x77    /* Indirect Access Data 0 */

#define KSZ8864_REG_ID1		0xfe	/* Chip ID in bit 7 */

#define KS8995_REGS_SIZE	0x80
#define KSZ8864_REGS_SIZE	0x100
#define KSZ8795_REGS_SIZE	0x100

#define ID1_CHIPID_M		0xf
#define ID1_CHIPID_S		4
#define ID1_REVISION_M		0x7
#define ID1_REVISION_S		1
#define ID1_START_SW		1	/* start the switch */

#define FAMILY_KS8995		0x95
#define FAMILY_KSZ8795		0x87
#define CHIPID_M		0
#define KS8995_CHIP_ID		0x00
#define KSZ8864_CHIP_ID		0x01
#define KSZ8795_CHIP_ID		0x09

#define KS8995_CMD_WRITE	0x02U
#define KS8995_CMD_READ		0x03U

#define KS8995_RESET_DELAY	10 /* usec */

enum ks8995_chip_variant {
	ks8995,
	ksz8864,
	ksz8795,
	max_variant
};

struct ks8995_chip_params {
	char *name;
	int family_id;
	int chip_id;
	int regs_size;
	int addr_width;
	int addr_shift;
};

static const struct ks8995_chip_params ks8995_chip[] = {
	[ks8995] = {
		.name = "KS8995MA",
		.family_id = FAMILY_KS8995,
		.chip_id = KS8995_CHIP_ID,
		.regs_size = KS8995_REGS_SIZE,
		.addr_width = 8,
		.addr_shift = 0,
	},
	[ksz8864] = {
		.name = "KSZ8864RMN",
		.family_id = FAMILY_KS8995,
		.chip_id = KSZ8864_CHIP_ID,
		.regs_size = KSZ8864_REGS_SIZE,
		.addr_width = 8,
		.addr_shift = 0,
	},
	[ksz8795] = {
		.name = "KSZ8795CLX",
		.family_id = FAMILY_KSZ8795,
		.chip_id = KSZ8795_CHIP_ID,
		.regs_size = KSZ8795_REGS_SIZE,
		.addr_width = 12,
		.addr_shift = 1,
	},
};

struct ks8995_pdata {
	int reset_gpio;
	enum of_gpio_flags reset_gpio_flags;
};

struct ks8995_switch {
	struct spi_device	*spi;
	struct mutex		lock;
	struct ks8995_pdata	*pdata;
	struct bin_attribute	regs_attr;
	const struct ks8995_chip_params	*chip;
	int			revision_id;
};

static const struct spi_device_id ks8995_id[] = {
	{"ks8995", ks8995},
	{"ksz8864", ksz8864},
	{"ksz8795", ksz8795},
	{ }
};
MODULE_DEVICE_TABLE(spi, ks8995_id);

static inline u8 get_chip_id(u8 val)
{
	return (val >> ID1_CHIPID_S) & ID1_CHIPID_M;
}

static inline u8 get_chip_rev(u8 val)
{
	return (val >> ID1_REVISION_S) & ID1_REVISION_M;
}

/* create_spi_cmd - create a chip specific SPI command header
 * @ks: pointer to switch instance
 * @cmd: SPI command for switch
 * @address: register address for command
 *
 * Different chip families use different bit pattern to address the switches
 * registers:
 *
 * KS8995: 8bit command + 8bit address
 * KSZ8795: 3bit command + 12bit address + 1bit TR (?)
 */
static inline __be16 create_spi_cmd(struct ks8995_switch *ks, int cmd,
				    unsigned address)
{
	u16 result = cmd;

	/* make room for address (incl. address shift) */
	result <<= ks->chip->addr_width + ks->chip->addr_shift;
	/* add address */
	result |= address << ks->chip->addr_shift;
	/* SPI protocol needs big endian */
	return cpu_to_be16(result);
}
/* ------------------------------------------------------------------------ */
static int ks8995_read(struct ks8995_switch *ks, char *buf,
		 unsigned offset, size_t count)
{
	__be16 cmd;
	struct spi_transfer t[2];
	struct spi_message m;
	int err;

	cmd = create_spi_cmd(ks, KS8995_CMD_READ, offset);
	spi_message_init(&m);

	memset(&t, 0, sizeof(t));

	t[0].tx_buf = &cmd;
	t[0].len = sizeof(cmd);
	spi_message_add_tail(&t[0], &m);

	t[1].rx_buf = buf;
	t[1].len = count;
	spi_message_add_tail(&t[1], &m);

	mutex_lock(&ks->lock);
	err = spi_sync(ks->spi, &m);
	mutex_unlock(&ks->lock);

	return err ? err : count;
}

static int ks8995_write(struct ks8995_switch *ks, char *buf,
		 unsigned offset, size_t count)
{
	__be16 cmd;
	struct spi_transfer t[2];
	struct spi_message m;
	int err;

	cmd = create_spi_cmd(ks, KS8995_CMD_WRITE, offset);
	spi_message_init(&m);

	memset(&t, 0, sizeof(t));

	t[0].tx_buf = &cmd;
	t[0].len = sizeof(cmd);
	spi_message_add_tail(&t[0], &m);

	t[1].tx_buf = buf;
	t[1].len = count;
	spi_message_add_tail(&t[1], &m);

	mutex_lock(&ks->lock);
	err = spi_sync(ks->spi, &m);
	mutex_unlock(&ks->lock);

	return err ? err : count;
}

static inline int ks8995_read_reg(struct ks8995_switch *ks, u8 addr, u8 *buf)
{
	return ks8995_read(ks, buf, addr, 1) != 1;
}

static inline int ks8995_write_reg(struct ks8995_switch *ks, u8 addr, u8 val)
{
	char buf = val;

	return ks8995_write(ks, &buf, addr, 1) != 1;
}

/* ------------------------------------------------------------------------ */

static int ks8995_stop(struct ks8995_switch *ks)
{
	return ks8995_write_reg(ks, KS8995_REG_ID1, 0);
}

static int ks8995_start(struct ks8995_switch *ks)
{
	return ks8995_write_reg(ks, KS8995_REG_ID1, 1);
}

static int ks8995_reset(struct ks8995_switch *ks)
{
	int err;

	err = ks8995_stop(ks);
	if (err)
		return err;

	udelay(KS8995_RESET_DELAY);

	return ks8995_start(ks);
}

static ssize_t ks8995_registers_read(struct file *filp, struct kobject *kobj,
	struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count)
{
	struct device *dev;
	struct ks8995_switch *ks8995;

	dev = container_of(kobj, struct device, kobj);
	ks8995 = dev_get_drvdata(dev);

	return ks8995_read(ks8995, buf, off, count);
}

static ssize_t ks8995_registers_write(struct file *filp, struct kobject *kobj,
	struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count)
{
	struct device *dev;
	struct ks8995_switch *ks8995;

	dev = container_of(kobj, struct device, kobj);
	ks8995 = dev_get_drvdata(dev);

	return ks8995_write(ks8995, buf, off, count);
}

/* ks8995_get_revision - get chip revision
 * @ks: pointer to switch instance
 *
 * Verify chip family and id and get chip revision.
 */
static int ks8995_get_revision(struct ks8995_switch *ks)
{
	int err;
	u8 id0, id1, ksz8864_id;

	/* read family id */
	err = ks8995_read_reg(ks, KS8995_REG_ID0, &id0);
	if (err) {
		err = -EIO;
		goto err_out;
	}

	/* verify family id */
	if (id0 != ks->chip->family_id) {
		dev_err(&ks->spi->dev, "chip family id mismatch: expected 0x%02x but 0x%02x read\n",
			ks->chip->family_id, id0);
		err = -ENODEV;
		goto err_out;
	}

	switch (ks->chip->family_id) {
	case FAMILY_KS8995:
		/* try reading chip id at CHIP ID1 */
		err = ks8995_read_reg(ks, KS8995_REG_ID1, &id1);
		if (err) {
			err = -EIO;
			goto err_out;
		}

		/* verify chip id */
		if ((get_chip_id(id1) == CHIPID_M) &&
		    (get_chip_id(id1) == ks->chip->chip_id)) {
			/* KS8995MA */
			ks->revision_id = get_chip_rev(id1);
		} else if (get_chip_id(id1) != CHIPID_M) {
			/* KSZ8864RMN */
			err = ks8995_read_reg(ks, KS8995_REG_ID1, &ksz8864_id);
			if (err) {
				err = -EIO;
				goto err_out;
			}

			if ((ksz8864_id & 0x80) &&
			    (ks->chip->chip_id == KSZ8864_CHIP_ID)) {
				ks->revision_id = get_chip_rev(id1);
			}

		} else {
			dev_err(&ks->spi->dev, "unsupported chip id for KS8995 family: 0x%02x\n",
				id1);
			err = -ENODEV;
		}
		break;
	case FAMILY_KSZ8795:
		/* try reading chip id at CHIP ID1 */
		err = ks8995_read_reg(ks, KS8995_REG_ID1, &id1);
		if (err) {
			err = -EIO;
			goto err_out;
		}

		if (get_chip_id(id1) == ks->chip->chip_id) {
			ks->revision_id = get_chip_rev(id1);
		} else {
			dev_err(&ks->spi->dev, "unsupported chip id for KSZ8795 family: 0x%02x\n",
				id1);
			err = -ENODEV;
		}
		break;
	default:
		dev_err(&ks->spi->dev, "unsupported family id: 0x%02x\n", id0);
		err = -ENODEV;
		break;
	}
err_out:
	return err;
}

/* ks8995_parse_dt - setup platform data from devicetree
 * @ks: pointer to switch instance
 *
 * Parses supported DT properties and sets up platform data
 * accordingly.
 */
static void ks8995_parse_dt(struct ks8995_switch *ks)
{
	struct device_node *np = ks->spi->dev.of_node;
	struct ks8995_pdata *pdata = ks->pdata;

	if (!np)
		return;

	pdata->reset_gpio = of_get_named_gpio_flags(np, "reset-gpios", 0,
		&pdata->reset_gpio_flags);
}

static const struct bin_attribute ks8995_registers_attr = {
	.attr = {
		.name   = "registers",
		.mode   = S_IRUSR | S_IWUSR,
	},
	.size   = KS8995_REGS_SIZE,
	.read   = ks8995_registers_read,
	.write  = ks8995_registers_write,
};

/* ------------------------------------------------------------------------ */
static int ks8995_probe(struct spi_device *spi)
{
	struct ks8995_switch *ks;
	int err;
	int variant = spi_get_device_id(spi)->driver_data;

	if (variant >= max_variant) {
		dev_err(&spi->dev, "bad chip variant %d\n", variant);
		return -ENODEV;
	}

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

	mutex_init(&ks->lock);
	ks->spi = spi;
	ks->chip = &ks8995_chip[variant];

	if (ks->spi->dev.of_node) {
		ks->pdata = devm_kzalloc(&spi->dev, sizeof(*ks->pdata),
					 GFP_KERNEL);
		if (!ks->pdata)
			return -ENOMEM;

		ks->pdata->reset_gpio = -1;

		ks8995_parse_dt(ks);
	}

	if (!ks->pdata)
		ks->pdata = spi->dev.platform_data;

	/* de-assert switch reset */
	if (ks->pdata && gpio_is_valid(ks->pdata->reset_gpio)) {
		unsigned long flags;

		flags = (ks->pdata->reset_gpio_flags == OF_GPIO_ACTIVE_LOW ?
			 GPIOF_ACTIVE_LOW : 0);

		err = devm_gpio_request_one(&spi->dev,
					    ks->pdata->reset_gpio,
					    flags, "switch-reset");
		if (err) {
			dev_err(&spi->dev,
				"failed to get reset-gpios: %d\n", err);
			return -EIO;
		}

		gpiod_set_value(gpio_to_desc(ks->pdata->reset_gpio), 0);
	}

	spi_set_drvdata(spi, ks);

	spi->mode = SPI_MODE_0;
	spi->bits_per_word = 8;
	err = spi_setup(spi);
	if (err) {
		dev_err(&spi->dev, "spi_setup failed, err=%d\n", err);
		return err;
	}

	err = ks8995_get_revision(ks);
	if (err)
		return err;

	memcpy(&ks->regs_attr, &ks8995_registers_attr, sizeof(ks->regs_attr));
	ks->regs_attr.size = ks->chip->regs_size;

	err = ks8995_reset(ks);
	if (err)
		return err;

	sysfs_attr_init(&ks->regs_attr.attr);
	err = sysfs_create_bin_file(&spi->dev.kobj, &ks->regs_attr);
	if (err) {
		dev_err(&spi->dev, "unable to create sysfs file, err=%d\n",
				    err);
		return err;
	}

	dev_info(&spi->dev, "%s device found, Chip ID:%x, Revision:%x\n",
		 ks->chip->name, ks->chip->chip_id, ks->revision_id);

	return 0;
}

static int ks8995_remove(struct spi_device *spi)
{
	struct ks8995_switch *ks = spi_get_drvdata(spi);

	sysfs_remove_bin_file(&spi->dev.kobj, &ks->regs_attr);

	/* assert reset */
	if (ks->pdata && gpio_is_valid(ks->pdata->reset_gpio))
		gpiod_set_value(gpio_to_desc(ks->pdata->reset_gpio), 1);

	return 0;
}

/* ------------------------------------------------------------------------ */
static struct spi_driver ks8995_driver = {
	.driver = {
		.name	    = "spi-ks8995",
	},
	.probe	  = ks8995_probe,
	.remove	  = ks8995_remove,
	.id_table = ks8995_id,
};

module_spi_driver(ks8995_driver);

MODULE_DESCRIPTION(DRV_DESC);
MODULE_VERSION(DRV_VERSION);
MODULE_AUTHOR("Gabor Juhos <juhosg at openwrt.org>");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
a8e510f6	1	/*
240a12d5	2	* SPI driver for Micrel/Kendin KS8995M and KSZ8864RMN ethernet switches
a8e510f6 FL	3	*
	4	* Copyright (C) 2008 Gabor Juhos <juhosg at openwrt.org>
	5	*
	6	* This file was based on: drivers/spi/at25.c
	7	* Copyright (C) 2006 David Brownell
	8	*
	9	* This program is free software; you can redistribute it and/or modify it
	10	* under the terms of the GNU General Public License version 2 as published
	11	* by the Free Software Foundation.
	12	*/
	13
8d242488 JP	14	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
8d242488 JP	15
a8e510f6 FL	16	#include <linux/types.h>
a8e510f6 FL	17	#include <linux/kernel.h>
a8e510f6 FL	18	#include <linux/module.h>
	19	#include <linux/delay.h>
	20	#include <linux/device.h>
27090cbd	21	#include <linux/gpio/consumer.h>
cd6f288c	22	#include <linux/of.h>
cd6f288c	23	#include <linux/of_gpio.h>
a8e510f6 FL	24
	25	#include <linux/spi/spi.h>
	26
	27	#define DRV_VERSION "0.1.1"
	28	#define DRV_DESC "Micrel KS8995 Ethernet switch SPI driver"
	29
	30	/* ------------------------------------------------------------------------ */
	31
	32	#define KS8995_REG_ID0 0x00 /* Chip ID0 */
	33	#define KS8995_REG_ID1 0x01 /* Chip ID1 */
	34
	35	#define KS8995_REG_GC0 0x02 /* Global Control 0 */
	36	#define KS8995_REG_GC1 0x03 /* Global Control 1 */
	37	#define KS8995_REG_GC2 0x04 /* Global Control 2 */
	38	#define KS8995_REG_GC3 0x05 /* Global Control 3 */
	39	#define KS8995_REG_GC4 0x06 /* Global Control 4 */
	40	#define KS8995_REG_GC5 0x07 /* Global Control 5 */
	41	#define KS8995_REG_GC6 0x08 /* Global Control 6 */
	42	#define KS8995_REG_GC7 0x09 /* Global Control 7 */
	43	#define KS8995_REG_GC8 0x0a /* Global Control 8 */
	44	#define KS8995_REG_GC9 0x0b /* Global Control 9 */
	45
	46	#define KS8995_REG_PC(p, r) ((0x10 * p) + r) /* Port Control */
	47	#define KS8995_REG_PS(p, r) ((0x10 * p) + r + 0xe) /* Port Status */
	48
	49	#define KS8995_REG_TPC0 0x60 /* TOS Priority Control 0 */
	50	#define KS8995_REG_TPC1 0x61 /* TOS Priority Control 1 */
	51	#define KS8995_REG_TPC2 0x62 /* TOS Priority Control 2 */
	52	#define KS8995_REG_TPC3 0x63 /* TOS Priority Control 3 */
	53	#define KS8995_REG_TPC4 0x64 /* TOS Priority Control 4 */
	54	#define KS8995_REG_TPC5 0x65 /* TOS Priority Control 5 */
	55	#define KS8995_REG_TPC6 0x66 /* TOS Priority Control 6 */
	56	#define KS8995_REG_TPC7 0x67 /* TOS Priority Control 7 */
	57
	58	#define KS8995_REG_MAC0 0x68 /* MAC address 0 */
	59	#define KS8995_REG_MAC1 0x69 /* MAC address 1 */
	60	#define KS8995_REG_MAC2 0x6a /* MAC address 2 */
	61	#define KS8995_REG_MAC3 0x6b /* MAC address 3 */
	62	#define KS8995_REG_MAC4 0x6c /* MAC address 4 */
	63	#define KS8995_REG_MAC5 0x6d /* MAC address 5 */
	64
	65	#define KS8995_REG_IAC0 0x6e /* Indirect Access Control 0 */
	66	#define KS8995_REG_IAC1 0x6f /* Indirect Access Control 0 */
	67	#define KS8995_REG_IAD7 0x70 /* Indirect Access Data 7 */
	68	#define KS8995_REG_IAD6 0x71 /* Indirect Access Data 6 */
	69	#define KS8995_REG_IAD5 0x72 /* Indirect Access Data 5 */
	70	#define KS8995_REG_IAD4 0x73 /* Indirect Access Data 4 */
	71	#define KS8995_REG_IAD3 0x74 /* Indirect Access Data 3 */
	72	#define KS8995_REG_IAD2 0x75 /* Indirect Access Data 2 */
	73	#define KS8995_REG_IAD1 0x76 /* Indirect Access Data 1 */
	74	#define KS8995_REG_IAD0 0x77 /* Indirect Access Data 0 */
	75
240a12d5 PZ	76	#define KSZ8864_REG_ID1 0xfe /* Chip ID in bit 7 */
240a12d5 PZ	77
a8e510f6	78	#define KS8995_REGS_SIZE 0x80
240a12d5	79	#define KSZ8864_REGS_SIZE 0x100
c0e6cb1f	80	#define KSZ8795_REGS_SIZE 0x100
a8e510f6 FL	81
	82	#define ID1_CHIPID_M 0xf
	83	#define ID1_CHIPID_S 4
	84	#define ID1_REVISION_M 0x7
	85	#define ID1_REVISION_S 1
	86	#define ID1_START_SW 1 /* start the switch */
	87
	88	#define FAMILY_KS8995 0x95
c0e6cb1f	89	#define FAMILY_KSZ8795 0x87
a8e510f6	90	#define CHIPID_M 0
484e36ff HB	91	#define KS8995_CHIP_ID 0x00
484e36ff HB	92	#define KSZ8864_CHIP_ID 0x01
c0e6cb1f	93	#define KSZ8795_CHIP_ID 0x09
a8e510f6 FL	94
	95	#define KS8995_CMD_WRITE 0x02U
	96	#define KS8995_CMD_READ 0x03U
	97
	98	#define KS8995_RESET_DELAY 10 /* usec */
	99
aa54c8da HB	100	enum ks8995_chip_variant {
	101	ks8995,
	102	ksz8864,
c0e6cb1f	103	ksz8795,
aa54c8da HB	104	max_variant
	105	};
	106
	107	struct ks8995_chip_params {
	108	char *name;
484e36ff HB	109	int family_id;
484e36ff HB	110	int chip_id;
aa54c8da	111	int regs_size;
6665e623 HB	112	int addr_width;
6665e623 HB	113	int addr_shift;
aa54c8da HB	114	};
	115
	116	static const struct ks8995_chip_params ks8995_chip[] = {
	117	[ks8995] = {
	118	.name = "KS8995MA",
484e36ff HB	119	.family_id = FAMILY_KS8995,
484e36ff HB	120	.chip_id = KS8995_CHIP_ID,
aa54c8da	121	.regs_size = KS8995_REGS_SIZE,
6665e623 HB	122	.addr_width = 8,
6665e623 HB	123	.addr_shift = 0,
aa54c8da HB	124	},
	125	[ksz8864] = {
	126	.name = "KSZ8864RMN",
484e36ff HB	127	.family_id = FAMILY_KS8995,
484e36ff HB	128	.chip_id = KSZ8864_CHIP_ID,
aa54c8da	129	.regs_size = KSZ8864_REGS_SIZE,
6665e623 HB	130	.addr_width = 8,
6665e623 HB	131	.addr_shift = 0,
aa54c8da	132	},
c0e6cb1f HB	133	[ksz8795] = {
	134	.name = "KSZ8795CLX",
	135	.family_id = FAMILY_KSZ8795,
	136	.chip_id = KSZ8795_CHIP_ID,
	137	.regs_size = KSZ8795_REGS_SIZE,
	138	.addr_width = 12,
	139	.addr_shift = 1,
	140	},
aa54c8da HB	141	};
aa54c8da HB	142
a8e510f6	143	struct ks8995_pdata {
cd6f288c HB	144	int reset_gpio;
cd6f288c HB	145	enum of_gpio_flags reset_gpio_flags;
a8e510f6 FL	146	};
	147
	148	struct ks8995_switch {
	149	struct spi_device *spi;
	150	struct mutex lock;
	151	struct ks8995_pdata *pdata;
240a12d5	152	struct bin_attribute regs_attr;
aa54c8da	153	const struct ks8995_chip_params *chip;
484e36ff	154	int revision_id;
a8e510f6 FL	155	};
a8e510f6 FL	156
aa54c8da HB	157	static const struct spi_device_id ks8995_id[] = {
	158	{"ks8995", ks8995},
	159	{"ksz8864", ksz8864},
c0e6cb1f	160	{"ksz8795", ksz8795},
aa54c8da HB	161	{ }
	162	};
	163	MODULE_DEVICE_TABLE(spi, ks8995_id);
	164
a8e510f6 FL	165	static inline u8 get_chip_id(u8 val)
	166	{
	167	return (val >> ID1_CHIPID_S) & ID1_CHIPID_M;
	168	}
	169
	170	static inline u8 get_chip_rev(u8 val)
	171	{
	172	return (val >> ID1_REVISION_S) & ID1_REVISION_M;
	173	}
	174
6665e623 HB	175	/* create_spi_cmd - create a chip specific SPI command header
	176	* @ks: pointer to switch instance
	177	* @cmd: SPI command for switch
	178	* @address: register address for command
	179	*
	180	* Different chip families use different bit pattern to address the switches
	181	* registers:
	182	*
	183	* KS8995: 8bit command + 8bit address
	184	* KSZ8795: 3bit command + 12bit address + 1bit TR (?)
	185	*/
	186	static inline __be16 create_spi_cmd(struct ks8995_switch *ks, int cmd,
	187	unsigned address)
	188	{
	189	u16 result = cmd;
	190
	191	/* make room for address (incl. address shift) */
	192	result <<= ks->chip->addr_width + ks->chip->addr_shift;
	193	/* add address */
	194	result \|= address << ks->chip->addr_shift;
	195	/* SPI protocol needs big endian */
	196	return cpu_to_be16(result);
	197	}
a8e510f6 FL	198	/* ------------------------------------------------------------------------ */
	199	static int ks8995_read(struct ks8995_switch ks, char buf,
	200	unsigned offset, size_t count)
	201	{
6665e623	202	__be16 cmd;
a8e510f6 FL	203	struct spi_transfer t[2];
	204	struct spi_message m;
	205	int err;
	206
6665e623	207	cmd = create_spi_cmd(ks, KS8995_CMD_READ, offset);
a8e510f6 FL	208	spi_message_init(&m);
	209
	210	memset(&t, 0, sizeof(t));
	211
6665e623	212	t[0].tx_buf = &cmd;
a8e510f6 FL	213	t[0].len = sizeof(cmd);
	214	spi_message_add_tail(&t[0], &m);
	215
	216	t[1].rx_buf = buf;
	217	t[1].len = count;
	218	spi_message_add_tail(&t[1], &m);
	219
a8e510f6 FL	220	mutex_lock(&ks->lock);
	221	err = spi_sync(ks->spi, &m);
	222	mutex_unlock(&ks->lock);
	223
	224	return err ? err : count;
	225	}
	226
a8e510f6 FL	227	static int ks8995_write(struct ks8995_switch ks, char buf,
	228	unsigned offset, size_t count)
	229	{
6665e623	230	__be16 cmd;
a8e510f6 FL	231	struct spi_transfer t[2];
	232	struct spi_message m;
	233	int err;
	234
6665e623	235	cmd = create_spi_cmd(ks, KS8995_CMD_WRITE, offset);
a8e510f6 FL	236	spi_message_init(&m);
	237
	238	memset(&t, 0, sizeof(t));
	239
6665e623	240	t[0].tx_buf = &cmd;
a8e510f6 FL	241	t[0].len = sizeof(cmd);
	242	spi_message_add_tail(&t[0], &m);
	243
	244	t[1].tx_buf = buf;
	245	t[1].len = count;
	246	spi_message_add_tail(&t[1], &m);
	247
a8e510f6 FL	248	mutex_lock(&ks->lock);
	249	err = spi_sync(ks->spi, &m);
	250	mutex_unlock(&ks->lock);
	251
	252	return err ? err : count;
	253	}
	254
	255	static inline int ks8995_read_reg(struct ks8995_switch ks, u8 addr, u8 buf)
	256	{
7aff9675	257	return ks8995_read(ks, buf, addr, 1) != 1;
a8e510f6 FL	258	}
	259
	260	static inline int ks8995_write_reg(struct ks8995_switch *ks, u8 addr, u8 val)
	261	{
	262	char buf = val;
	263
7aff9675	264	return ks8995_write(ks, &buf, addr, 1) != 1;
a8e510f6 FL	265	}
	266
	267	/* ------------------------------------------------------------------------ */
	268
	269	static int ks8995_stop(struct ks8995_switch *ks)
	270	{
	271	return ks8995_write_reg(ks, KS8995_REG_ID1, 0);
	272	}
	273
	274	static int ks8995_start(struct ks8995_switch *ks)
	275	{
	276	return ks8995_write_reg(ks, KS8995_REG_ID1, 1);
	277	}
	278
	279	static int ks8995_reset(struct ks8995_switch *ks)
	280	{
	281	int err;
	282
	283	err = ks8995_stop(ks);
	284	if (err)
	285	return err;
	286
	287	udelay(KS8995_RESET_DELAY);
	288
	289	return ks8995_start(ks);
	290	}
	291
a8e510f6 FL	292	static ssize_t ks8995_registers_read(struct file filp, struct kobject kobj,
	293	struct bin_attribute bin_attr, char buf, loff_t off, size_t count)
	294	{
	295	struct device *dev;
	296	struct ks8995_switch *ks8995;
	297
	298	dev = container_of(kobj, struct device, kobj);
	299	ks8995 = dev_get_drvdata(dev);
	300
a8e510f6 FL	301	return ks8995_read(ks8995, buf, off, count);
	302	}
	303
a8e510f6 FL	304	static ssize_t ks8995_registers_write(struct file filp, struct kobject kobj,
	305	struct bin_attribute bin_attr, char buf, loff_t off, size_t count)
	306	{
	307	struct device *dev;
	308	struct ks8995_switch *ks8995;
	309
	310	dev = container_of(kobj, struct device, kobj);
	311	ks8995 = dev_get_drvdata(dev);
	312
a8e510f6 FL	313	return ks8995_write(ks8995, buf, off, count);
	314	}
	315
484e36ff HB	316	/* ks8995_get_revision - get chip revision
	317	* @ks: pointer to switch instance
	318	*
	319	* Verify chip family and id and get chip revision.
	320	*/
	321	static int ks8995_get_revision(struct ks8995_switch *ks)
	322	{
	323	int err;
	324	u8 id0, id1, ksz8864_id;
	325
	326	/* read family id */
	327	err = ks8995_read_reg(ks, KS8995_REG_ID0, &id0);
	328	if (err) {
	329	err = -EIO;
	330	goto err_out;
	331	}
	332
	333	/* verify family id */
	334	if (id0 != ks->chip->family_id) {
	335	dev_err(&ks->spi->dev, "chip family id mismatch: expected 0x%02x but 0x%02x read\n",
	336	ks->chip->family_id, id0);
	337	err = -ENODEV;
	338	goto err_out;
	339	}
	340
	341	switch (ks->chip->family_id) {
	342	case FAMILY_KS8995:
	343	/* try reading chip id at CHIP ID1 */
	344	err = ks8995_read_reg(ks, KS8995_REG_ID1, &id1);
	345	if (err) {
	346	err = -EIO;
	347	goto err_out;
	348	}
	349
	350	/* verify chip id */
	351	if ((get_chip_id(id1) == CHIPID_M) &&
	352	(get_chip_id(id1) == ks->chip->chip_id)) {
	353	/* KS8995MA */
	354	ks->revision_id = get_chip_rev(id1);
	355	} else if (get_chip_id(id1) != CHIPID_M) {
	356	/* KSZ8864RMN */
	357	err = ks8995_read_reg(ks, KS8995_REG_ID1, &ksz8864_id);
	358	if (err) {
	359	err = -EIO;
	360	goto err_out;
	361	}
	362
	363	if ((ksz8864_id & 0x80) &&
	364	(ks->chip->chip_id == KSZ8864_CHIP_ID)) {
	365	ks->revision_id = get_chip_rev(id1);
	366	}
	367
	368	} else {
	369	dev_err(&ks->spi->dev, "unsupported chip id for KS8995 family: 0x%02x\n",
	370	id1);
	371	err = -ENODEV;
	372	}
	373	break;
c0e6cb1f HB	374	case FAMILY_KSZ8795:
	375	/* try reading chip id at CHIP ID1 */
	376	err = ks8995_read_reg(ks, KS8995_REG_ID1, &id1);
	377	if (err) {
	378	err = -EIO;
	379	goto err_out;
	380	}
	381
	382	if (get_chip_id(id1) == ks->chip->chip_id) {
	383	ks->revision_id = get_chip_rev(id1);
	384	} else {
	385	dev_err(&ks->spi->dev, "unsupported chip id for KSZ8795 family: 0x%02x\n",
	386	id1);
	387	err = -ENODEV;
	388	}
	389	break;
484e36ff HB	390	default:
	391	dev_err(&ks->spi->dev, "unsupported family id: 0x%02x\n", id0);
	392	err = -ENODEV;
	393	break;
	394	}
	395	err_out:
	396	return err;
	397	}
	398
cd6f288c HB	399	/* ks8995_parse_dt - setup platform data from devicetree
	400	* @ks: pointer to switch instance
	401	*
	402	* Parses supported DT properties and sets up platform data
	403	* accordingly.
	404	*/
	405	static void ks8995_parse_dt(struct ks8995_switch *ks)
	406	{
	407	struct device_node *np = ks->spi->dev.of_node;
	408	struct ks8995_pdata *pdata = ks->pdata;
	409
	410	if (!np)
	411	return;
	412
	413	pdata->reset_gpio = of_get_named_gpio_flags(np, "reset-gpios", 0,
	414	&pdata->reset_gpio_flags);
	415	}
	416
240a12d5	417	static const struct bin_attribute ks8995_registers_attr = {
a8e510f6 FL	418	.attr = {
	419	.name = "registers",
	420	.mode = S_IRUSR \| S_IWUSR,
	421	},
	422	.size = KS8995_REGS_SIZE,
	423	.read = ks8995_registers_read,
	424	.write = ks8995_registers_write,
	425	};
	426
	427	/* ------------------------------------------------------------------------ */
633d1594	428	static int ks8995_probe(struct spi_device *spi)
a8e510f6	429	{
cd6f288c HB	430	struct ks8995_switch *ks;
cd6f288c HB	431	int err;
aa54c8da	432	int variant = spi_get_device_id(spi)->driver_data;
a8e510f6	433
aa54c8da HB	434	if (variant >= max_variant) {
	435	dev_err(&spi->dev, "bad chip variant %d\n", variant);
	436	return -ENODEV;
	437	}
	438
b32a8b64	439	ks = devm_kzalloc(&spi->dev, sizeof(*ks), GFP_KERNEL);
e68ed8f0	440	if (!ks)
a8e510f6	441	return -ENOMEM;
a8e510f6 FL	442
a8e510f6 FL	443	mutex_init(&ks->lock);
a1459c1c	444	ks->spi = spi;
aa54c8da HB	445	ks->chip = &ks8995_chip[variant];
aa54c8da HB	446
cd6f288c HB	447	if (ks->spi->dev.of_node) {
	448	ks->pdata = devm_kzalloc(&spi->dev, sizeof(*ks->pdata),
	449	GFP_KERNEL);
	450	if (!ks->pdata)
	451	return -ENOMEM;
	452
	453	ks->pdata->reset_gpio = -1;
	454
	455	ks8995_parse_dt(ks);
	456	}
	457
	458	if (!ks->pdata)
	459	ks->pdata = spi->dev.platform_data;
	460
	461	/* de-assert switch reset */
	462	if (ks->pdata && gpio_is_valid(ks->pdata->reset_gpio)) {
	463	unsigned long flags;
	464
	465	flags = (ks->pdata->reset_gpio_flags == OF_GPIO_ACTIVE_LOW ?
	466	GPIOF_ACTIVE_LOW : 0);
	467
	468	err = devm_gpio_request_one(&spi->dev,
	469	ks->pdata->reset_gpio,
	470	flags, "switch-reset");
	471	if (err) {
	472	dev_err(&spi->dev,
	473	"failed to get reset-gpios: %d\n", err);
	474	return -EIO;
	475	}
	476
	477	gpiod_set_value(gpio_to_desc(ks->pdata->reset_gpio), 0);
	478	}
	479
5d5f1846	480	spi_set_drvdata(spi, ks);
a8e510f6 FL	481
	482	spi->mode = SPI_MODE_0;
	483	spi->bits_per_word = 8;
	484	err = spi_setup(spi);
	485	if (err) {
	486	dev_err(&spi->dev, "spi_setup failed, err=%d\n", err);
b32a8b64	487	return err;
a8e510f6 FL	488	}
a8e510f6 FL	489
484e36ff HB	490	err = ks8995_get_revision(ks);
484e36ff HB	491	if (err)
b32a8b64	492	return err;
a8e510f6	493
240a12d5	494	memcpy(&ks->regs_attr, &ks8995_registers_attr, sizeof(ks->regs_attr));
239870f2	495	ks->regs_attr.size = ks->chip->regs_size;
240a12d5	496
a8e510f6 FL	497	err = ks8995_reset(ks);
a8e510f6 FL	498	if (err)
b32a8b64	499	return err;
a8e510f6	500
4342696d	501	sysfs_attr_init(&ks->regs_attr.attr);
240a12d5	502	err = sysfs_create_bin_file(&spi->dev.kobj, &ks->regs_attr);
a8e510f6 FL	503	if (err) {
	504	dev_err(&spi->dev, "unable to create sysfs file, err=%d\n",
	505	err);
b32a8b64	506	return err;
a8e510f6 FL	507	}
a8e510f6 FL	508
484e36ff HB	509	dev_info(&spi->dev, "%s device found, Chip ID:%x, Revision:%x\n",
484e36ff HB	510	ks->chip->name, ks->chip->chip_id, ks->revision_id);
a8e510f6 FL	511
a8e510f6 FL	512	return 0;
a8e510f6 FL	513	}
a8e510f6 FL	514
633d1594	515	static int ks8995_remove(struct spi_device *spi)
a8e510f6	516	{
30349bdb VZ	517	struct ks8995_switch *ks = spi_get_drvdata(spi);
	518
	519	sysfs_remove_bin_file(&spi->dev.kobj, &ks->regs_attr);
a8e510f6	520
cd6f288c HB	521	/* assert reset */
	522	if (ks->pdata && gpio_is_valid(ks->pdata->reset_gpio))
	523	gpiod_set_value(gpio_to_desc(ks->pdata->reset_gpio), 1);
	524
a8e510f6 FL	525	return 0;
	526	}
	527
	528	/* ------------------------------------------------------------------------ */
a8e510f6 FL	529	static struct spi_driver ks8995_driver = {
	530	.driver = {
	531	.name = "spi-ks8995",
a8e510f6 FL	532	},
a8e510f6 FL	533	.probe = ks8995_probe,
633d1594	534	.remove = ks8995_remove,
aa54c8da	535	.id_table = ks8995_id,
a8e510f6 FL	536	};
a8e510f6 FL	537
1a9561a3	538	module_spi_driver(ks8995_driver);
a8e510f6 FL	539
	540	MODULE_DESCRIPTION(DRV_DESC);
	541	MODULE_VERSION(DRV_VERSION);
	542	MODULE_AUTHOR("Gabor Juhos <juhosg at openwrt.org>");
	543	MODULE_LICENSE("GPL v2");