188 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Copyright 2009-2010 Pengutronix4 * Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>5 *6 * loosely based on an earlier driver that has7 * Copyright 2009 Pengutronix, Sascha Hauer <s.hauer@pengutronix.de>8 */9 10#include <linux/slab.h>11#include <linux/mod_devicetable.h>12#include <linux/module.h>13#include <linux/platform_device.h>14#include <linux/interrupt.h>15#include <linux/mfd/core.h>16#include <linux/mfd/mc13xxx.h>17#include <linux/err.h>18#include <linux/spi/spi.h>19 20#include "mc13xxx.h"21 22static const struct spi_device_id mc13xxx_device_id[] = {23 {24 .name = "mc13783",25 .driver_data = (kernel_ulong_t)&mc13xxx_variant_mc13783,26 }, {27 .name = "mc13892",28 .driver_data = (kernel_ulong_t)&mc13xxx_variant_mc13892,29 }, {30 .name = "mc34708",31 .driver_data = (kernel_ulong_t)&mc13xxx_variant_mc34708,32 }, {33 /* sentinel */34 }35};36MODULE_DEVICE_TABLE(spi, mc13xxx_device_id);37 38static const struct of_device_id mc13xxx_dt_ids[] = {39 { .compatible = "fsl,mc13783", .data = &mc13xxx_variant_mc13783, },40 { .compatible = "fsl,mc13892", .data = &mc13xxx_variant_mc13892, },41 { .compatible = "fsl,mc34708", .data = &mc13xxx_variant_mc34708, },42 { /* sentinel */ }43};44MODULE_DEVICE_TABLE(of, mc13xxx_dt_ids);45 46static const struct regmap_config mc13xxx_regmap_spi_config = {47 .reg_bits = 7,48 .pad_bits = 1,49 .val_bits = 24,50 .write_flag_mask = 0x80,51 52 .max_register = MC13XXX_NUMREGS,53 54 .cache_type = REGCACHE_NONE,55 .use_single_read = true,56 .use_single_write = true,57};58 59static int mc13xxx_spi_read(void *context, const void *reg, size_t reg_size,60 void *val, size_t val_size)61{62 unsigned char w[4] = { *((unsigned char *) reg), 0, 0, 0};63 unsigned char r[4];64 unsigned char *p = val;65 struct device *dev = context;66 struct spi_device *spi = to_spi_device(dev);67 struct spi_transfer t = {68 .tx_buf = w,69 .rx_buf = r,70 .len = 4,71 };72 73 struct spi_message m;74 int ret;75 76 if (val_size != 3 || reg_size != 1)77 return -ENOTSUPP;78 79 spi_message_init(&m);80 spi_message_add_tail(&t, &m);81 ret = spi_sync(spi, &m);82 83 memcpy(p, &r[1], 3);84 85 return ret;86}87 88static int mc13xxx_spi_write(void *context, const void *data, size_t count)89{90 struct device *dev = context;91 struct spi_device *spi = to_spi_device(dev);92 const char *reg = data;93 94 if (count != 4)95 return -ENOTSUPP;96 97 /* include errata fix for spi audio problems */98 if (*reg == MC13783_AUDIO_CODEC || *reg == MC13783_AUDIO_DAC)99 spi_write(spi, data, count);100 101 return spi_write(spi, data, count);102}103 104/*105 * We cannot use regmap-spi generic bus implementation here.106 * The MC13783 chip will get corrupted if CS signal is deasserted107 * and on i.Mx31 SoC (the target SoC for MC13783 PMIC) the SPI controller108 * has the following errata (DSPhl22960):109 * "The CSPI negates SS when the FIFO becomes empty with110 * SSCTL= 0. Software cannot guarantee that the FIFO will not111 * drain because of higher priority interrupts and the112 * non-realtime characteristics of the operating system. As a113 * result, the SS will negate before all of the data has been114 * transferred to/from the peripheral."115 * We workaround this by accessing the SPI controller with a116 * single transfer.117 */118 119static const struct regmap_bus regmap_mc13xxx_bus = {120 .write = mc13xxx_spi_write,121 .read = mc13xxx_spi_read,122};123 124static int mc13xxx_spi_probe(struct spi_device *spi)125{126 struct mc13xxx *mc13xxx;127 int ret;128 129 mc13xxx = devm_kzalloc(&spi->dev, sizeof(*mc13xxx), GFP_KERNEL);130 if (!mc13xxx)131 return -ENOMEM;132 133 dev_set_drvdata(&spi->dev, mc13xxx);134 135 spi->mode = SPI_MODE_0 | SPI_CS_HIGH;136 137 mc13xxx->irq = spi->irq;138 139 spi->max_speed_hz = spi->max_speed_hz ? : 26000000;140 ret = spi_setup(spi);141 if (ret)142 return ret;143 144 mc13xxx->regmap = devm_regmap_init(&spi->dev, ®map_mc13xxx_bus,145 &spi->dev,146 &mc13xxx_regmap_spi_config);147 if (IS_ERR(mc13xxx->regmap)) {148 ret = PTR_ERR(mc13xxx->regmap);149 dev_err(&spi->dev, "Failed to initialize regmap: %d\n", ret);150 return ret;151 }152 153 mc13xxx->variant = spi_get_device_match_data(spi);154 155 return mc13xxx_common_init(&spi->dev);156}157 158static void mc13xxx_spi_remove(struct spi_device *spi)159{160 mc13xxx_common_exit(&spi->dev);161}162 163static struct spi_driver mc13xxx_spi_driver = {164 .id_table = mc13xxx_device_id,165 .driver = {166 .name = "mc13xxx",167 .of_match_table = mc13xxx_dt_ids,168 },169 .probe = mc13xxx_spi_probe,170 .remove = mc13xxx_spi_remove,171};172 173static int __init mc13xxx_init(void)174{175 return spi_register_driver(&mc13xxx_spi_driver);176}177subsys_initcall(mc13xxx_init);178 179static void __exit mc13xxx_exit(void)180{181 spi_unregister_driver(&mc13xxx_spi_driver);182}183module_exit(mc13xxx_exit);184 185MODULE_DESCRIPTION("Core driver for Freescale MC13XXX PMIC");186MODULE_AUTHOR("Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>");187MODULE_LICENSE("GPL v2");188