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273 lines
6.4 KiB
273 lines
6.4 KiB
// SPDX-License-Identifier: GPL-2.0+ |
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/* |
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* SPI driver for Renesas Synchronization Management Unit (SMU) devices. |
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* |
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* Copyright (C) 2021 Integrated Device Technology, Inc., a Renesas Company. |
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*/ |
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#include <linux/init.h> |
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#include <linux/kernel.h> |
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#include <linux/mfd/core.h> |
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#include <linux/mfd/rsmu.h> |
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#include <linux/module.h> |
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#include <linux/of.h> |
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#include <linux/regmap.h> |
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#include <linux/slab.h> |
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#include <linux/spi/spi.h> |
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#include "rsmu.h" |
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#define RSMU_CM_PAGE_ADDR 0x7C |
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#define RSMU_SABRE_PAGE_ADDR 0x7F |
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#define RSMU_HIGHER_ADDR_MASK 0xFF80 |
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#define RSMU_HIGHER_ADDR_SHIFT 7 |
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#define RSMU_LOWER_ADDR_MASK 0x7F |
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static int rsmu_read_device(struct rsmu_ddata *rsmu, u8 reg, u8 *buf, u16 bytes) |
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{ |
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struct spi_device *client = to_spi_device(rsmu->dev); |
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struct spi_transfer xfer = {0}; |
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struct spi_message msg; |
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u8 cmd[256] = {0}; |
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u8 rsp[256] = {0}; |
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int ret; |
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cmd[0] = reg | 0x80; |
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xfer.rx_buf = rsp; |
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xfer.len = bytes + 1; |
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xfer.tx_buf = cmd; |
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xfer.bits_per_word = client->bits_per_word; |
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xfer.speed_hz = client->max_speed_hz; |
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spi_message_init(&msg); |
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spi_message_add_tail(&xfer, &msg); |
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/* |
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* 4-wire SPI is a shift register, so for every byte you send, |
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* you get one back at the same time. Example read from 0xC024, |
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* which has value of 0x2D |
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* |
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* MOSI: |
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* 7C 00 C0 #Set page register |
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* A4 00 #MSB is set, so this is read command |
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* MISO: |
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* XX 2D #XX is a dummy byte from sending A4 and we |
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* need to throw it away |
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*/ |
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ret = spi_sync(client, &msg); |
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if (ret >= 0) |
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memcpy(buf, &rsp[1], xfer.len-1); |
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return ret; |
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} |
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static int rsmu_write_device(struct rsmu_ddata *rsmu, u8 reg, u8 *buf, u16 bytes) |
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{ |
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struct spi_device *client = to_spi_device(rsmu->dev); |
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struct spi_transfer xfer = {0}; |
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struct spi_message msg; |
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u8 cmd[256] = {0}; |
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cmd[0] = reg; |
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memcpy(&cmd[1], buf, bytes); |
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xfer.len = bytes + 1; |
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xfer.tx_buf = cmd; |
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xfer.bits_per_word = client->bits_per_word; |
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xfer.speed_hz = client->max_speed_hz; |
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spi_message_init(&msg); |
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spi_message_add_tail(&xfer, &msg); |
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return spi_sync(client, &msg); |
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} |
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/* |
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* 1-byte (1B) offset addressing: |
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* 16-bit register address: the lower 7 bits of the register address come |
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* from the offset addr byte and the upper 9 bits come from the page register. |
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*/ |
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static int rsmu_write_page_register(struct rsmu_ddata *rsmu, u16 reg) |
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{ |
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u8 page_reg; |
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u8 buf[2]; |
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u16 bytes; |
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u16 page; |
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int err; |
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switch (rsmu->type) { |
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case RSMU_CM: |
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page_reg = RSMU_CM_PAGE_ADDR; |
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page = reg & RSMU_HIGHER_ADDR_MASK; |
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buf[0] = (u8)(page & 0xff); |
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buf[1] = (u8)((page >> 8) & 0xff); |
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bytes = 2; |
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break; |
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case RSMU_SABRE: |
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page_reg = RSMU_SABRE_PAGE_ADDR; |
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page = reg >> RSMU_HIGHER_ADDR_SHIFT; |
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buf[0] = (u8)(page & 0xff); |
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bytes = 1; |
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break; |
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default: |
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dev_err(rsmu->dev, "Unsupported RSMU device type: %d\n", rsmu->type); |
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return -ENODEV; |
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} |
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/* Simply return if we are on the same page */ |
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if (rsmu->page == page) |
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return 0; |
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err = rsmu_write_device(rsmu, page_reg, buf, bytes); |
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if (err) |
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dev_err(rsmu->dev, "Failed to set page offset 0x%x\n", page); |
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else |
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/* Remember the last page */ |
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rsmu->page = page; |
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return err; |
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} |
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static int rsmu_reg_read(void *context, unsigned int reg, unsigned int *val) |
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{ |
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struct rsmu_ddata *rsmu = spi_get_drvdata((struct spi_device *)context); |
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u8 addr = (u8)(reg & RSMU_LOWER_ADDR_MASK); |
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int err; |
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err = rsmu_write_page_register(rsmu, reg); |
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if (err) |
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return err; |
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err = rsmu_read_device(rsmu, addr, (u8 *)val, 1); |
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if (err) |
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dev_err(rsmu->dev, "Failed to read offset address 0x%x\n", addr); |
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return err; |
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} |
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static int rsmu_reg_write(void *context, unsigned int reg, unsigned int val) |
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{ |
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struct rsmu_ddata *rsmu = spi_get_drvdata((struct spi_device *)context); |
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u8 addr = (u8)(reg & RSMU_LOWER_ADDR_MASK); |
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u8 data = (u8)val; |
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int err; |
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err = rsmu_write_page_register(rsmu, reg); |
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if (err) |
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return err; |
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err = rsmu_write_device(rsmu, addr, &data, 1); |
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if (err) |
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dev_err(rsmu->dev, |
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"Failed to write offset address 0x%x\n", addr); |
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return err; |
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} |
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static const struct regmap_config rsmu_cm_regmap_config = { |
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.reg_bits = 16, |
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.val_bits = 8, |
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.max_register = 0xD000, |
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.reg_read = rsmu_reg_read, |
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.reg_write = rsmu_reg_write, |
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.cache_type = REGCACHE_NONE, |
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}; |
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static const struct regmap_config rsmu_sabre_regmap_config = { |
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.reg_bits = 16, |
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.val_bits = 8, |
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.max_register = 0x400, |
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.reg_read = rsmu_reg_read, |
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.reg_write = rsmu_reg_write, |
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.cache_type = REGCACHE_NONE, |
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}; |
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static int rsmu_spi_probe(struct spi_device *client) |
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{ |
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const struct spi_device_id *id = spi_get_device_id(client); |
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const struct regmap_config *cfg; |
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struct rsmu_ddata *rsmu; |
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int ret; |
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rsmu = devm_kzalloc(&client->dev, sizeof(*rsmu), GFP_KERNEL); |
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if (!rsmu) |
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return -ENOMEM; |
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spi_set_drvdata(client, rsmu); |
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rsmu->dev = &client->dev; |
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rsmu->type = (enum rsmu_type)id->driver_data; |
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/* Initialize regmap */ |
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switch (rsmu->type) { |
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case RSMU_CM: |
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cfg = &rsmu_cm_regmap_config; |
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break; |
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case RSMU_SABRE: |
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cfg = &rsmu_sabre_regmap_config; |
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break; |
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default: |
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dev_err(rsmu->dev, "Unsupported RSMU device type: %d\n", rsmu->type); |
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return -ENODEV; |
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} |
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rsmu->regmap = devm_regmap_init(&client->dev, NULL, client, cfg); |
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if (IS_ERR(rsmu->regmap)) { |
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ret = PTR_ERR(rsmu->regmap); |
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dev_err(rsmu->dev, "Failed to allocate register map: %d\n", ret); |
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return ret; |
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} |
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return rsmu_core_init(rsmu); |
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} |
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static int rsmu_spi_remove(struct spi_device *client) |
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{ |
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struct rsmu_ddata *rsmu = spi_get_drvdata(client); |
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rsmu_core_exit(rsmu); |
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return 0; |
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} |
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static const struct spi_device_id rsmu_spi_id[] = { |
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{ "8a34000", RSMU_CM }, |
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{ "8a34001", RSMU_CM }, |
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{ "82p33810", RSMU_SABRE }, |
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{ "82p33811", RSMU_SABRE }, |
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{} |
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}; |
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MODULE_DEVICE_TABLE(spi, rsmu_spi_id); |
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static const struct of_device_id rsmu_spi_of_match[] = { |
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{ .compatible = "idt,8a34000", .data = (void *)RSMU_CM }, |
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{ .compatible = "idt,8a34001", .data = (void *)RSMU_CM }, |
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{ .compatible = "idt,82p33810", .data = (void *)RSMU_SABRE }, |
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{ .compatible = "idt,82p33811", .data = (void *)RSMU_SABRE }, |
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{} |
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}; |
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MODULE_DEVICE_TABLE(of, rsmu_spi_of_match); |
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static struct spi_driver rsmu_spi_driver = { |
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.driver = { |
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.name = "rsmu-spi", |
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.of_match_table = of_match_ptr(rsmu_spi_of_match), |
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}, |
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.probe = rsmu_spi_probe, |
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.remove = rsmu_spi_remove, |
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.id_table = rsmu_spi_id, |
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}; |
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static int __init rsmu_spi_init(void) |
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{ |
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return spi_register_driver(&rsmu_spi_driver); |
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} |
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subsys_initcall(rsmu_spi_init); |
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static void __exit rsmu_spi_exit(void) |
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{ |
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spi_unregister_driver(&rsmu_spi_driver); |
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} |
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module_exit(rsmu_spi_exit); |
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MODULE_DESCRIPTION("Renesas SMU SPI driver"); |
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MODULE_LICENSE("GPL");
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