| /* |
| * 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_dev_get(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; |
| |
| ks->regs_attr.size = ks->chip->regs_size; |
| memcpy(&ks->regs_attr, &ks8995_registers_attr, sizeof(ks->regs_attr)); |
| |
| err = ks8995_reset(ks); |
| if (err) |
| return err; |
| |
| 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"); |