diff options
Diffstat (limited to 'drivers/net/phy/spi_ks8995.c')
| -rw-r--r-- | drivers/net/phy/spi_ks8995.c | 506 |
1 files changed, 506 insertions, 0 deletions
diff --git a/drivers/net/phy/spi_ks8995.c b/drivers/net/phy/spi_ks8995.c new file mode 100644 index 000000000..d4202d40d --- /dev/null +++ b/drivers/net/phy/spi_ks8995.c @@ -0,0 +1,506 @@ +// 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/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_switch { + struct spi_device *spi; + struct mutex lock; + struct gpio_desc *reset_gpio; + 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; +} + +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]; + + ks->reset_gpio = devm_gpiod_get_optional(&spi->dev, "reset", + GPIOD_OUT_HIGH); + err = PTR_ERR_OR_ZERO(ks->reset_gpio); + if (err) { + dev_err(&spi->dev, + "failed to get reset gpio: %d\n", err); + return err; + } + + err = gpiod_set_consumer_name(ks->reset_gpio, "switch-reset"); + if (err) + return err; + + /* de-assert switch reset */ + /* FIXME: this likely requires a delay */ + gpiod_set_value_cansleep(ks->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 void 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 */ + gpiod_set_value_cansleep(ks->reset_gpio, 1); +} + +/* ------------------------------------------------------------------------ */ +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"); |