1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright 2009-2010 Pengutronix 4 * Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de> 5 * 6 * loosely based on an earlier driver that has 7 * 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 22 static 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 }; 36 MODULE_DEVICE_TABLE(spi, mc13xxx_device_id); 37 38 static 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 }; 44 MODULE_DEVICE_TABLE(of, mc13xxx_dt_ids); 45 46 static 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 59 static 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 88 static 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 deasserted 107 * and on i.Mx31 SoC (the target SoC for MC13783 PMIC) the SPI controller 108 * has the following errata (DSPhl22960): 109 * "The CSPI negates SS when the FIFO becomes empty with 110 * SSCTL= 0. Software cannot guarantee that the FIFO will not 111 * drain because of higher priority interrupts and the 112 * non-realtime characteristics of the operating system. As a 113 * result, the SS will negate before all of the data has been 114 * transferred to/from the peripheral." 115 * We workaround this by accessing the SPI controller with a 116 * single transfer. 117 */ 118 119 static struct regmap_bus regmap_mc13xxx_bus = { 120 .write = mc13xxx_spi_write, 121 .read = mc13xxx_spi_read, 122 }; 123 124 static 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 } 157 158 static void mc13xxx_spi_remove(struct spi_device *spi) 159 { 160 mc13xxx_common_exit(&spi->dev); 161 } 162 163 static 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 }; 172 173 static int __init mc13xxx_init(void) 174 { 175 return spi_register_driver(&mc13xxx_spi_driver); 176 } 177 subsys_initcall(mc13xxx_init); 178 179 static void __exit mc13xxx_exit(void) 180 { 181 spi_unregister_driver(&mc13xxx_spi_driver); 182 } 183 module_exit(mc13xxx_exit); 184 185 MODULE_DESCRIPTION("Core driver for Freescale MC13XXX PMIC"); 186 MODULE_AUTHOR("Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>"); 187 MODULE_LICENSE("GPL v2"); 188