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1// SPDX-License-Identifier: GPL-2.0+2/*3 * SPI driver for Renesas Synchronization Management Unit (SMU) devices.4 *5 * Copyright (C) 2021 Integrated Device Technology, Inc., a Renesas Company.6 */7 8#include <linux/init.h>9#include <linux/kernel.h>10#include <linux/mfd/core.h>11#include <linux/mfd/rsmu.h>12#include <linux/module.h>13#include <linux/of.h>14#include <linux/regmap.h>15#include <linux/slab.h>16#include <linux/spi/spi.h>17 18#include "rsmu.h"19 20#define RSMU_CM_PAGE_ADDR 0x7C21#define RSMU_SABRE_PAGE_ADDR 0x7F22#define RSMU_PAGE_MASK 0xFFFFFF8023#define RSMU_ADDR_MASK 0x7F24 25static int rsmu_read_device(struct rsmu_ddata *rsmu, u8 reg, u8 *buf, u16 bytes)26{27 struct spi_device *client = to_spi_device(rsmu->dev);28 struct spi_transfer xfer = {0};29 struct spi_message msg;30 u8 cmd[RSMU_MAX_READ_COUNT + 1] = {0};31 u8 rsp[RSMU_MAX_READ_COUNT + 1] = {0};32 int ret;33 34 if (bytes > RSMU_MAX_READ_COUNT)35 return -EINVAL;36 37 cmd[0] = reg | 0x80;38 xfer.rx_buf = rsp;39 xfer.len = bytes + 1;40 xfer.tx_buf = cmd;41 xfer.bits_per_word = client->bits_per_word;42 xfer.speed_hz = client->max_speed_hz;43 44 spi_message_init(&msg);45 spi_message_add_tail(&xfer, &msg);46 47 /*48 * 4-wire SPI is a shift register, so for every byte you send,49 * you get one back at the same time. Example read from 0xC024,50 * which has value of 0x2D51 *52 * MOSI:53 * 7C 00 C0 #Set page register54 * A4 00 #MSB is set, so this is read command55 * MISO:56 * XX 2D #XX is a dummy byte from sending A4 and we57 * need to throw it away58 */59 ret = spi_sync(client, &msg);60 if (ret >= 0)61 memcpy(buf, &rsp[1], xfer.len-1);62 63 return ret;64}65 66static int rsmu_write_device(struct rsmu_ddata *rsmu, u8 reg, u8 *buf, u16 bytes)67{68 struct spi_device *client = to_spi_device(rsmu->dev);69 struct spi_transfer xfer = {0};70 struct spi_message msg;71 u8 cmd[RSMU_MAX_WRITE_COUNT + 1] = {0};72 73 if (bytes > RSMU_MAX_WRITE_COUNT)74 return -EINVAL;75 76 cmd[0] = reg;77 memcpy(&cmd[1], buf, bytes);78 79 xfer.len = bytes + 1;80 xfer.tx_buf = cmd;81 xfer.bits_per_word = client->bits_per_word;82 xfer.speed_hz = client->max_speed_hz;83 spi_message_init(&msg);84 spi_message_add_tail(&xfer, &msg);85 86 return spi_sync(client, &msg);87}88 89/*90 * 1-byte (1B) offset addressing:91 * 16-bit register address: the lower 7 bits of the register address come92 * from the offset addr byte and the upper 9 bits come from the page register.93 */94static int rsmu_write_page_register(struct rsmu_ddata *rsmu, u32 reg)95{96 u8 page_reg;97 u8 buf[4];98 u16 bytes;99 u32 page;100 int err;101 102 switch (rsmu->type) {103 case RSMU_CM:104 /* Do not modify page register for none-scsr registers */105 if (reg < RSMU_CM_SCSR_BASE)106 return 0;107 page_reg = RSMU_CM_PAGE_ADDR;108 page = reg & RSMU_PAGE_MASK;109 buf[0] = (u8)(page & 0xFF);110 buf[1] = (u8)((page >> 8) & 0xFF);111 buf[2] = (u8)((page >> 16) & 0xFF);112 buf[3] = (u8)((page >> 24) & 0xFF);113 bytes = 4;114 break;115 case RSMU_SABRE:116 /* Do not modify page register if reg is page register itself */117 if ((reg & RSMU_ADDR_MASK) == RSMU_ADDR_MASK)118 return 0;119 page_reg = RSMU_SABRE_PAGE_ADDR;120 page = reg & RSMU_PAGE_MASK;121 /* The three page bits are located in the single Page Register */122 buf[0] = (u8)((page >> 7) & 0x7);123 bytes = 1;124 break;125 default:126 dev_err(rsmu->dev, "Unsupported RSMU device type: %d\n", rsmu->type);127 return -ENODEV;128 }129 130 /* Simply return if we are on the same page */131 if (rsmu->page == page)132 return 0;133 134 err = rsmu_write_device(rsmu, page_reg, buf, bytes);135 if (err)136 dev_err(rsmu->dev, "Failed to set page offset 0x%x\n", page);137 else138 /* Remember the last page */139 rsmu->page = page;140 141 return err;142}143 144static int rsmu_reg_read(void *context, unsigned int reg, unsigned int *val)145{146 struct rsmu_ddata *rsmu = spi_get_drvdata((struct spi_device *)context);147 u8 addr = (u8)(reg & RSMU_ADDR_MASK);148 int err;149 150 err = rsmu_write_page_register(rsmu, reg);151 if (err)152 return err;153 154 err = rsmu_read_device(rsmu, addr, (u8 *)val, 1);155 if (err)156 dev_err(rsmu->dev, "Failed to read offset address 0x%x\n", addr);157 158 return err;159}160 161static int rsmu_reg_write(void *context, unsigned int reg, unsigned int val)162{163 struct rsmu_ddata *rsmu = spi_get_drvdata((struct spi_device *)context);164 u8 addr = (u8)(reg & RSMU_ADDR_MASK);165 u8 data = (u8)val;166 int err;167 168 err = rsmu_write_page_register(rsmu, reg);169 if (err)170 return err;171 172 err = rsmu_write_device(rsmu, addr, &data, 1);173 if (err)174 dev_err(rsmu->dev,175 "Failed to write offset address 0x%x\n", addr);176 177 return err;178}179 180static const struct regmap_config rsmu_cm_regmap_config = {181 .reg_bits = 32,182 .val_bits = 8,183 .max_register = 0x20120000,184 .reg_read = rsmu_reg_read,185 .reg_write = rsmu_reg_write,186 .cache_type = REGCACHE_NONE,187};188 189static const struct regmap_config rsmu_sabre_regmap_config = {190 .reg_bits = 16,191 .val_bits = 8,192 .max_register = 0x400,193 .reg_read = rsmu_reg_read,194 .reg_write = rsmu_reg_write,195 .cache_type = REGCACHE_NONE,196};197 198static int rsmu_spi_probe(struct spi_device *client)199{200 const struct spi_device_id *id = spi_get_device_id(client);201 const struct regmap_config *cfg;202 struct rsmu_ddata *rsmu;203 int ret;204 205 rsmu = devm_kzalloc(&client->dev, sizeof(*rsmu), GFP_KERNEL);206 if (!rsmu)207 return -ENOMEM;208 209 spi_set_drvdata(client, rsmu);210 211 rsmu->dev = &client->dev;212 rsmu->type = (enum rsmu_type)id->driver_data;213 214 /* Initialize regmap */215 switch (rsmu->type) {216 case RSMU_CM:217 cfg = &rsmu_cm_regmap_config;218 break;219 case RSMU_SABRE:220 cfg = &rsmu_sabre_regmap_config;221 break;222 default:223 dev_err(rsmu->dev, "Unsupported RSMU device type: %d\n", rsmu->type);224 return -ENODEV;225 }226 227 rsmu->regmap = devm_regmap_init(&client->dev, NULL, client, cfg);228 if (IS_ERR(rsmu->regmap)) {229 ret = PTR_ERR(rsmu->regmap);230 dev_err(rsmu->dev, "Failed to allocate register map: %d\n", ret);231 return ret;232 }233 234 return rsmu_core_init(rsmu);235}236 237static void rsmu_spi_remove(struct spi_device *client)238{239 struct rsmu_ddata *rsmu = spi_get_drvdata(client);240 241 rsmu_core_exit(rsmu);242}243 244static const struct spi_device_id rsmu_spi_id[] = {245 { "8a34000", RSMU_CM },246 { "8a34001", RSMU_CM },247 { "82p33810", RSMU_SABRE },248 { "82p33811", RSMU_SABRE },249 {}250};251MODULE_DEVICE_TABLE(spi, rsmu_spi_id);252 253static const struct of_device_id rsmu_spi_of_match[] = {254 { .compatible = "idt,8a34000", .data = (void *)RSMU_CM },255 { .compatible = "idt,8a34001", .data = (void *)RSMU_CM },256 { .compatible = "idt,82p33810", .data = (void *)RSMU_SABRE },257 { .compatible = "idt,82p33811", .data = (void *)RSMU_SABRE },258 {}259};260MODULE_DEVICE_TABLE(of, rsmu_spi_of_match);261 262static struct spi_driver rsmu_spi_driver = {263 .driver = {264 .name = "rsmu-spi",265 .of_match_table = rsmu_spi_of_match,266 },267 .probe = rsmu_spi_probe,268 .remove = rsmu_spi_remove,269 .id_table = rsmu_spi_id,270};271 272static int __init rsmu_spi_init(void)273{274 return spi_register_driver(&rsmu_spi_driver);275}276subsys_initcall(rsmu_spi_init);277 278static void __exit rsmu_spi_exit(void)279{280 spi_unregister_driver(&rsmu_spi_driver);281}282module_exit(rsmu_spi_exit);283 284MODULE_DESCRIPTION("Renesas SMU SPI driver");285MODULE_LICENSE("GPL");286