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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * ST Microelectronics MFD: stmpe's spi client specific driver4 *5 * Copyright (C) ST Microelectronics SA 20116 *7 * Author: Viresh Kumar <vireshk@kernel.org> for ST Microelectronics8 */9 10#include <linux/spi/spi.h>11#include <linux/interrupt.h>12#include <linux/kernel.h>13#include <linux/module.h>14#include <linux/of.h>15#include <linux/types.h>16#include "stmpe.h"17 18#define READ_CMD (1 << 7)19 20static int spi_reg_read(struct stmpe *stmpe, u8 reg)21{22 struct spi_device *spi = stmpe->client;23 int status = spi_w8r16(spi, reg | READ_CMD);24 25 return (status < 0) ? status : status >> 8;26}27 28static int spi_reg_write(struct stmpe *stmpe, u8 reg, u8 val)29{30 struct spi_device *spi = stmpe->client;31 u16 cmd = (val << 8) | reg;32 33 return spi_write(spi, (const u8 *)&cmd, 2);34}35 36static int spi_block_read(struct stmpe *stmpe, u8 reg, u8 length, u8 *values)37{38 int ret, i;39 40 for (i = 0; i < length; i++) {41 ret = spi_reg_read(stmpe, reg + i);42 if (ret < 0)43 return ret;44 *(values + i) = ret;45 }46 47 return 0;48}49 50static int spi_block_write(struct stmpe *stmpe, u8 reg, u8 length,51 const u8 *values)52{53 int ret = 0, i;54 55 for (i = length; i > 0; i--, reg++) {56 ret = spi_reg_write(stmpe, reg, *(values + i - 1));57 if (ret < 0)58 return ret;59 }60 61 return ret;62}63 64static void spi_init(struct stmpe *stmpe)65{66 struct spi_device *spi = stmpe->client;67 68 spi->bits_per_word = 8;69 70 /* This register is only present for stmpe811 */71 if (stmpe->variant->id_val == 0x0811)72 spi_reg_write(stmpe, STMPE811_REG_SPI_CFG, spi->mode);73 74 if (spi_setup(spi) < 0)75 dev_dbg(&spi->dev, "spi_setup failed\n");76}77 78static struct stmpe_client_info spi_ci = {79 .read_byte = spi_reg_read,80 .write_byte = spi_reg_write,81 .read_block = spi_block_read,82 .write_block = spi_block_write,83 .init = spi_init,84};85 86static int87stmpe_spi_probe(struct spi_device *spi)88{89 const struct spi_device_id *id = spi_get_device_id(spi);90 91 /* don't exceed max specified rate - 1MHz - Limitation of STMPE */92 if (spi->max_speed_hz > 1000000) {93 dev_dbg(&spi->dev, "f(sample) %d KHz?\n",94 (spi->max_speed_hz/1000));95 return -EINVAL;96 }97 98 spi_ci.irq = spi->irq;99 spi_ci.client = spi;100 spi_ci.dev = &spi->dev;101 102 return stmpe_probe(&spi_ci, id->driver_data);103}104 105static void stmpe_spi_remove(struct spi_device *spi)106{107 struct stmpe *stmpe = spi_get_drvdata(spi);108 109 stmpe_remove(stmpe);110}111 112static const struct of_device_id stmpe_spi_of_match[] = {113 { .compatible = "st,stmpe610", },114 { .compatible = "st,stmpe801", },115 { .compatible = "st,stmpe811", },116 { .compatible = "st,stmpe1601", },117 { .compatible = "st,stmpe2401", },118 { .compatible = "st,stmpe2403", },119 { /* sentinel */ },120};121MODULE_DEVICE_TABLE(of, stmpe_spi_of_match);122 123static const struct spi_device_id stmpe_spi_id[] = {124 { "stmpe610", STMPE610 },125 { "stmpe801", STMPE801 },126 { "stmpe811", STMPE811 },127 { "stmpe1601", STMPE1601 },128 { "stmpe2401", STMPE2401 },129 { "stmpe2403", STMPE2403 },130 { }131};132MODULE_DEVICE_TABLE(spi, stmpe_id);133 134static struct spi_driver stmpe_spi_driver = {135 .driver = {136 .name = "stmpe-spi",137 .of_match_table = of_match_ptr(stmpe_spi_of_match),138 .pm = pm_sleep_ptr(&stmpe_dev_pm_ops),139 },140 .probe = stmpe_spi_probe,141 .remove = stmpe_spi_remove,142 .id_table = stmpe_spi_id,143};144 145static int __init stmpe_init(void)146{147 return spi_register_driver(&stmpe_spi_driver);148}149subsys_initcall(stmpe_init);150 151static void __exit stmpe_exit(void)152{153 spi_unregister_driver(&stmpe_spi_driver);154}155module_exit(stmpe_exit);156 157MODULE_DESCRIPTION("STMPE MFD SPI Interface Driver");158MODULE_AUTHOR("Viresh Kumar <vireshk@kernel.org>");159