https://github.com/torvalds/linux
Tip revision: 1e28eed17697bcf343c6743f0028cc3b5dd88bf0 authored by Linus Torvalds on 14 March 2021, 21:41:02 UTC
Linux 5.12-rc3
Linux 5.12-rc3
Tip revision: 1e28eed
spi_ks8995.c
// SPDX-License-Identifier: GPL-2.0
/*
* 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
*/
#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 const struct of_device_id ks8895_spi_of_match[] = {
{ .compatible = "micrel,ks8995" },
{ .compatible = "micrel,ksz8864" },
{ .compatible = "micrel,ksz8795" },
{ },
};
MODULE_DEVICE_TABLE(of, ks8895_spi_of_match);
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 = kobj_to_dev(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 = kobj_to_dev(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 = 0600,
},
.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",
.of_match_table = of_match_ptr(ks8895_spi_of_match),
},
.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");