507 lines
12 KiB
C
507 lines
12 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* SPI driver for Micrel/Kendin KS8995M and KSZ8864RMN ethernet switches
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*
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* Copyright (C) 2008 Gabor Juhos <juhosg at openwrt.org>
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*
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* This file was based on: drivers/spi/at25.c
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* Copyright (C) 2006 David Brownell
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/delay.h>
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#include <linux/device.h>
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#include <linux/gpio/consumer.h>
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#include <linux/of.h>
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#include <linux/spi/spi.h>
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#define DRV_VERSION "0.1.1"
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#define DRV_DESC "Micrel KS8995 Ethernet switch SPI driver"
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/* ------------------------------------------------------------------------ */
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#define KS8995_REG_ID0 0x00 /* Chip ID0 */
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#define KS8995_REG_ID1 0x01 /* Chip ID1 */
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#define KS8995_REG_GC0 0x02 /* Global Control 0 */
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#define KS8995_REG_GC1 0x03 /* Global Control 1 */
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#define KS8995_REG_GC2 0x04 /* Global Control 2 */
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#define KS8995_REG_GC3 0x05 /* Global Control 3 */
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#define KS8995_REG_GC4 0x06 /* Global Control 4 */
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#define KS8995_REG_GC5 0x07 /* Global Control 5 */
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#define KS8995_REG_GC6 0x08 /* Global Control 6 */
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#define KS8995_REG_GC7 0x09 /* Global Control 7 */
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#define KS8995_REG_GC8 0x0a /* Global Control 8 */
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#define KS8995_REG_GC9 0x0b /* Global Control 9 */
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#define KS8995_REG_PC(p, r) ((0x10 * p) + r) /* Port Control */
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#define KS8995_REG_PS(p, r) ((0x10 * p) + r + 0xe) /* Port Status */
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#define KS8995_REG_TPC0 0x60 /* TOS Priority Control 0 */
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#define KS8995_REG_TPC1 0x61 /* TOS Priority Control 1 */
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#define KS8995_REG_TPC2 0x62 /* TOS Priority Control 2 */
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#define KS8995_REG_TPC3 0x63 /* TOS Priority Control 3 */
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#define KS8995_REG_TPC4 0x64 /* TOS Priority Control 4 */
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#define KS8995_REG_TPC5 0x65 /* TOS Priority Control 5 */
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#define KS8995_REG_TPC6 0x66 /* TOS Priority Control 6 */
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#define KS8995_REG_TPC7 0x67 /* TOS Priority Control 7 */
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#define KS8995_REG_MAC0 0x68 /* MAC address 0 */
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#define KS8995_REG_MAC1 0x69 /* MAC address 1 */
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#define KS8995_REG_MAC2 0x6a /* MAC address 2 */
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#define KS8995_REG_MAC3 0x6b /* MAC address 3 */
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#define KS8995_REG_MAC4 0x6c /* MAC address 4 */
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#define KS8995_REG_MAC5 0x6d /* MAC address 5 */
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#define KS8995_REG_IAC0 0x6e /* Indirect Access Control 0 */
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#define KS8995_REG_IAC1 0x6f /* Indirect Access Control 0 */
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#define KS8995_REG_IAD7 0x70 /* Indirect Access Data 7 */
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#define KS8995_REG_IAD6 0x71 /* Indirect Access Data 6 */
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#define KS8995_REG_IAD5 0x72 /* Indirect Access Data 5 */
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#define KS8995_REG_IAD4 0x73 /* Indirect Access Data 4 */
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#define KS8995_REG_IAD3 0x74 /* Indirect Access Data 3 */
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#define KS8995_REG_IAD2 0x75 /* Indirect Access Data 2 */
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#define KS8995_REG_IAD1 0x76 /* Indirect Access Data 1 */
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#define KS8995_REG_IAD0 0x77 /* Indirect Access Data 0 */
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#define KSZ8864_REG_ID1 0xfe /* Chip ID in bit 7 */
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#define KS8995_REGS_SIZE 0x80
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#define KSZ8864_REGS_SIZE 0x100
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#define KSZ8795_REGS_SIZE 0x100
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#define ID1_CHIPID_M 0xf
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#define ID1_CHIPID_S 4
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#define ID1_REVISION_M 0x7
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#define ID1_REVISION_S 1
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#define ID1_START_SW 1 /* start the switch */
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#define FAMILY_KS8995 0x95
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#define FAMILY_KSZ8795 0x87
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#define CHIPID_M 0
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#define KS8995_CHIP_ID 0x00
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#define KSZ8864_CHIP_ID 0x01
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#define KSZ8795_CHIP_ID 0x09
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#define KS8995_CMD_WRITE 0x02U
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#define KS8995_CMD_READ 0x03U
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#define KS8995_RESET_DELAY 10 /* usec */
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enum ks8995_chip_variant {
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ks8995,
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ksz8864,
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ksz8795,
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max_variant
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};
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struct ks8995_chip_params {
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char *name;
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int family_id;
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int chip_id;
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int regs_size;
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int addr_width;
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int addr_shift;
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};
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static const struct ks8995_chip_params ks8995_chip[] = {
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[ks8995] = {
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.name = "KS8995MA",
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.family_id = FAMILY_KS8995,
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.chip_id = KS8995_CHIP_ID,
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.regs_size = KS8995_REGS_SIZE,
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.addr_width = 8,
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.addr_shift = 0,
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},
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[ksz8864] = {
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.name = "KSZ8864RMN",
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.family_id = FAMILY_KS8995,
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.chip_id = KSZ8864_CHIP_ID,
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.regs_size = KSZ8864_REGS_SIZE,
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.addr_width = 8,
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.addr_shift = 0,
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},
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[ksz8795] = {
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.name = "KSZ8795CLX",
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.family_id = FAMILY_KSZ8795,
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.chip_id = KSZ8795_CHIP_ID,
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.regs_size = KSZ8795_REGS_SIZE,
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.addr_width = 12,
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.addr_shift = 1,
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},
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};
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struct ks8995_switch {
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struct spi_device *spi;
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struct mutex lock;
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struct gpio_desc *reset_gpio;
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struct bin_attribute regs_attr;
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const struct ks8995_chip_params *chip;
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int revision_id;
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};
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static const struct spi_device_id ks8995_id[] = {
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{"ks8995", ks8995},
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{"ksz8864", ksz8864},
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{"ksz8795", ksz8795},
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{ }
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};
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MODULE_DEVICE_TABLE(spi, ks8995_id);
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static const struct of_device_id ks8895_spi_of_match[] = {
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{ .compatible = "micrel,ks8995" },
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{ .compatible = "micrel,ksz8864" },
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{ .compatible = "micrel,ksz8795" },
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{ },
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};
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MODULE_DEVICE_TABLE(of, ks8895_spi_of_match);
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static inline u8 get_chip_id(u8 val)
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{
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return (val >> ID1_CHIPID_S) & ID1_CHIPID_M;
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}
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static inline u8 get_chip_rev(u8 val)
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{
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return (val >> ID1_REVISION_S) & ID1_REVISION_M;
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}
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/* create_spi_cmd - create a chip specific SPI command header
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* @ks: pointer to switch instance
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* @cmd: SPI command for switch
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* @address: register address for command
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*
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* Different chip families use different bit pattern to address the switches
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* registers:
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*
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* KS8995: 8bit command + 8bit address
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* KSZ8795: 3bit command + 12bit address + 1bit TR (?)
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*/
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static inline __be16 create_spi_cmd(struct ks8995_switch *ks, int cmd,
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unsigned address)
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{
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u16 result = cmd;
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/* make room for address (incl. address shift) */
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result <<= ks->chip->addr_width + ks->chip->addr_shift;
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/* add address */
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result |= address << ks->chip->addr_shift;
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/* SPI protocol needs big endian */
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return cpu_to_be16(result);
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}
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/* ------------------------------------------------------------------------ */
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static int ks8995_read(struct ks8995_switch *ks, char *buf,
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unsigned offset, size_t count)
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{
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__be16 cmd;
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struct spi_transfer t[2];
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struct spi_message m;
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int err;
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cmd = create_spi_cmd(ks, KS8995_CMD_READ, offset);
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spi_message_init(&m);
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memset(&t, 0, sizeof(t));
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t[0].tx_buf = &cmd;
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t[0].len = sizeof(cmd);
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spi_message_add_tail(&t[0], &m);
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t[1].rx_buf = buf;
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t[1].len = count;
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spi_message_add_tail(&t[1], &m);
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mutex_lock(&ks->lock);
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err = spi_sync(ks->spi, &m);
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mutex_unlock(&ks->lock);
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return err ? err : count;
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}
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static int ks8995_write(struct ks8995_switch *ks, char *buf,
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unsigned offset, size_t count)
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{
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__be16 cmd;
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struct spi_transfer t[2];
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struct spi_message m;
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int err;
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cmd = create_spi_cmd(ks, KS8995_CMD_WRITE, offset);
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spi_message_init(&m);
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memset(&t, 0, sizeof(t));
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t[0].tx_buf = &cmd;
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t[0].len = sizeof(cmd);
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spi_message_add_tail(&t[0], &m);
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t[1].tx_buf = buf;
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t[1].len = count;
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spi_message_add_tail(&t[1], &m);
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mutex_lock(&ks->lock);
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err = spi_sync(ks->spi, &m);
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mutex_unlock(&ks->lock);
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return err ? err : count;
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}
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static inline int ks8995_read_reg(struct ks8995_switch *ks, u8 addr, u8 *buf)
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{
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return ks8995_read(ks, buf, addr, 1) != 1;
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}
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static inline int ks8995_write_reg(struct ks8995_switch *ks, u8 addr, u8 val)
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{
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char buf = val;
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return ks8995_write(ks, &buf, addr, 1) != 1;
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}
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/* ------------------------------------------------------------------------ */
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static int ks8995_stop(struct ks8995_switch *ks)
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{
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return ks8995_write_reg(ks, KS8995_REG_ID1, 0);
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}
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static int ks8995_start(struct ks8995_switch *ks)
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{
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return ks8995_write_reg(ks, KS8995_REG_ID1, 1);
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}
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static int ks8995_reset(struct ks8995_switch *ks)
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{
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int err;
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err = ks8995_stop(ks);
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if (err)
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return err;
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udelay(KS8995_RESET_DELAY);
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return ks8995_start(ks);
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}
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static ssize_t ks8995_registers_read(struct file *filp, struct kobject *kobj,
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struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count)
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{
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struct device *dev;
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struct ks8995_switch *ks8995;
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dev = kobj_to_dev(kobj);
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ks8995 = dev_get_drvdata(dev);
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return ks8995_read(ks8995, buf, off, count);
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}
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static ssize_t ks8995_registers_write(struct file *filp, struct kobject *kobj,
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struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count)
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{
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struct device *dev;
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struct ks8995_switch *ks8995;
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dev = kobj_to_dev(kobj);
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ks8995 = dev_get_drvdata(dev);
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return ks8995_write(ks8995, buf, off, count);
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}
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/* ks8995_get_revision - get chip revision
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* @ks: pointer to switch instance
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*
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* Verify chip family and id and get chip revision.
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*/
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static int ks8995_get_revision(struct ks8995_switch *ks)
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{
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int err;
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u8 id0, id1, ksz8864_id;
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/* read family id */
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err = ks8995_read_reg(ks, KS8995_REG_ID0, &id0);
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if (err) {
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err = -EIO;
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goto err_out;
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}
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/* verify family id */
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if (id0 != ks->chip->family_id) {
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dev_err(&ks->spi->dev, "chip family id mismatch: expected 0x%02x but 0x%02x read\n",
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ks->chip->family_id, id0);
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err = -ENODEV;
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goto err_out;
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}
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switch (ks->chip->family_id) {
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case FAMILY_KS8995:
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/* try reading chip id at CHIP ID1 */
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err = ks8995_read_reg(ks, KS8995_REG_ID1, &id1);
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if (err) {
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err = -EIO;
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goto err_out;
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}
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/* verify chip id */
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if ((get_chip_id(id1) == CHIPID_M) &&
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(get_chip_id(id1) == ks->chip->chip_id)) {
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/* KS8995MA */
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ks->revision_id = get_chip_rev(id1);
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} else if (get_chip_id(id1) != CHIPID_M) {
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/* KSZ8864RMN */
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err = ks8995_read_reg(ks, KS8995_REG_ID1, &ksz8864_id);
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if (err) {
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err = -EIO;
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goto err_out;
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}
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if ((ksz8864_id & 0x80) &&
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(ks->chip->chip_id == KSZ8864_CHIP_ID)) {
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ks->revision_id = get_chip_rev(id1);
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}
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} else {
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dev_err(&ks->spi->dev, "unsupported chip id for KS8995 family: 0x%02x\n",
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id1);
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err = -ENODEV;
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}
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break;
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case FAMILY_KSZ8795:
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/* try reading chip id at CHIP ID1 */
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err = ks8995_read_reg(ks, KS8995_REG_ID1, &id1);
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if (err) {
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err = -EIO;
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goto err_out;
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}
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if (get_chip_id(id1) == ks->chip->chip_id) {
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ks->revision_id = get_chip_rev(id1);
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} else {
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dev_err(&ks->spi->dev, "unsupported chip id for KSZ8795 family: 0x%02x\n",
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id1);
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err = -ENODEV;
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}
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break;
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default:
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dev_err(&ks->spi->dev, "unsupported family id: 0x%02x\n", id0);
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err = -ENODEV;
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break;
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}
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err_out:
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return err;
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}
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static const struct bin_attribute ks8995_registers_attr = {
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.attr = {
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.name = "registers",
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.mode = 0600,
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},
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.size = KS8995_REGS_SIZE,
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.read = ks8995_registers_read,
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.write = ks8995_registers_write,
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};
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/* ------------------------------------------------------------------------ */
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static int ks8995_probe(struct spi_device *spi)
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{
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struct ks8995_switch *ks;
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int err;
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int variant = spi_get_device_id(spi)->driver_data;
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if (variant >= max_variant) {
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dev_err(&spi->dev, "bad chip variant %d\n", variant);
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return -ENODEV;
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}
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ks = devm_kzalloc(&spi->dev, sizeof(*ks), GFP_KERNEL);
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if (!ks)
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return -ENOMEM;
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mutex_init(&ks->lock);
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ks->spi = spi;
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ks->chip = &ks8995_chip[variant];
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ks->reset_gpio = devm_gpiod_get_optional(&spi->dev, "reset",
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GPIOD_OUT_HIGH);
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err = PTR_ERR_OR_ZERO(ks->reset_gpio);
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if (err) {
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dev_err(&spi->dev,
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"failed to get reset gpio: %d\n", err);
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return err;
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}
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err = gpiod_set_consumer_name(ks->reset_gpio, "switch-reset");
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if (err)
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return err;
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/* de-assert switch reset */
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/* FIXME: this likely requires a delay */
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gpiod_set_value_cansleep(ks->reset_gpio, 0);
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spi_set_drvdata(spi, ks);
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spi->mode = SPI_MODE_0;
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spi->bits_per_word = 8;
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err = spi_setup(spi);
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if (err) {
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dev_err(&spi->dev, "spi_setup failed, err=%d\n", err);
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return err;
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}
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err = ks8995_get_revision(ks);
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if (err)
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return err;
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memcpy(&ks->regs_attr, &ks8995_registers_attr, sizeof(ks->regs_attr));
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ks->regs_attr.size = ks->chip->regs_size;
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err = ks8995_reset(ks);
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if (err)
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return err;
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sysfs_attr_init(&ks->regs_attr.attr);
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err = sysfs_create_bin_file(&spi->dev.kobj, &ks->regs_attr);
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if (err) {
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dev_err(&spi->dev, "unable to create sysfs file, err=%d\n",
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err);
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return err;
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}
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dev_info(&spi->dev, "%s device found, Chip ID:%x, Revision:%x\n",
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ks->chip->name, ks->chip->chip_id, ks->revision_id);
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return 0;
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}
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static void ks8995_remove(struct spi_device *spi)
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{
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struct ks8995_switch *ks = spi_get_drvdata(spi);
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sysfs_remove_bin_file(&spi->dev.kobj, &ks->regs_attr);
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/* assert reset */
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gpiod_set_value_cansleep(ks->reset_gpio, 1);
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}
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/* ------------------------------------------------------------------------ */
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static struct spi_driver ks8995_driver = {
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.driver = {
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.name = "spi-ks8995",
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.of_match_table = 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");
|