1 /* 2 * Copyright 2009-2010 Pengutronix 3 * Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de> 4 * 5 * loosely based on an earlier driver that has 6 * Copyright 2009 Pengutronix, Sascha Hauer <s.hauer@pengutronix.de> 7 * 8 * This program is free software; you can redistribute it and/or modify it under 9 * the terms of the GNU General Public License version 2 as published by the 10 * Free Software Foundation. 11 */ 12 13 #include <linux/slab.h> 14 #include <linux/module.h> 15 #include <linux/platform_device.h> 16 #include <linux/interrupt.h> 17 #include <linux/mfd/core.h> 18 #include <linux/mfd/mc13xxx.h> 19 #include <linux/of.h> 20 #include <linux/of_device.h> 21 #include <linux/of_gpio.h> 22 #include <linux/err.h> 23 #include <linux/spi/spi.h> 24 25 #include "mc13xxx.h" 26 27 static const struct spi_device_id mc13xxx_device_id[] = { 28 { 29 .name = "mc13783", 30 .driver_data = (kernel_ulong_t)&mc13xxx_variant_mc13783, 31 }, { 32 .name = "mc13892", 33 .driver_data = (kernel_ulong_t)&mc13xxx_variant_mc13892, 34 }, { 35 .name = "mc34708", 36 .driver_data = (kernel_ulong_t)&mc13xxx_variant_mc34708, 37 }, { 38 /* sentinel */ 39 } 40 }; 41 MODULE_DEVICE_TABLE(spi, mc13xxx_device_id); 42 43 static const struct of_device_id mc13xxx_dt_ids[] = { 44 { .compatible = "fsl,mc13783", .data = &mc13xxx_variant_mc13783, }, 45 { .compatible = "fsl,mc13892", .data = &mc13xxx_variant_mc13892, }, 46 { .compatible = "fsl,mc34708", .data = &mc13xxx_variant_mc34708, }, 47 { /* sentinel */ } 48 }; 49 MODULE_DEVICE_TABLE(of, mc13xxx_dt_ids); 50 51 static const struct regmap_config mc13xxx_regmap_spi_config = { 52 .reg_bits = 7, 53 .pad_bits = 1, 54 .val_bits = 24, 55 .write_flag_mask = 0x80, 56 57 .max_register = MC13XXX_NUMREGS, 58 59 .cache_type = REGCACHE_NONE, 60 .use_single_read = true, 61 .use_single_write = true, 62 }; 63 64 static int mc13xxx_spi_read(void *context, const void *reg, size_t reg_size, 65 void *val, size_t val_size) 66 { 67 unsigned char w[4] = { *((unsigned char *) reg), 0, 0, 0}; 68 unsigned char r[4]; 69 unsigned char *p = val; 70 struct device *dev = context; 71 struct spi_device *spi = to_spi_device(dev); 72 struct spi_transfer t = { 73 .tx_buf = w, 74 .rx_buf = r, 75 .len = 4, 76 }; 77 78 struct spi_message m; 79 int ret; 80 81 if (val_size != 3 || reg_size != 1) 82 return -ENOTSUPP; 83 84 spi_message_init(&m); 85 spi_message_add_tail(&t, &m); 86 ret = spi_sync(spi, &m); 87 88 memcpy(p, &r[1], 3); 89 90 return ret; 91 } 92 93 static int mc13xxx_spi_write(void *context, const void *data, size_t count) 94 { 95 struct device *dev = context; 96 struct spi_device *spi = to_spi_device(dev); 97 const char *reg = data; 98 99 if (count != 4) 100 return -ENOTSUPP; 101 102 /* include errata fix for spi audio problems */ 103 if (*reg == MC13783_AUDIO_CODEC || *reg == MC13783_AUDIO_DAC) 104 spi_write(spi, data, count); 105 106 return spi_write(spi, data, count); 107 } 108 109 /* 110 * We cannot use regmap-spi generic bus implementation here. 111 * The MC13783 chip will get corrupted if CS signal is deasserted 112 * and on i.Mx31 SoC (the target SoC for MC13783 PMIC) the SPI controller 113 * has the following errata (DSPhl22960): 114 * "The CSPI negates SS when the FIFO becomes empty with 115 * SSCTL= 0. Software cannot guarantee that the FIFO will not 116 * drain because of higher priority interrupts and the 117 * non-realtime characteristics of the operating system. As a 118 * result, the SS will negate before all of the data has been 119 * transferred to/from the peripheral." 120 * We workaround this by accessing the SPI controller with a 121 * single transfert. 122 */ 123 124 static struct regmap_bus regmap_mc13xxx_bus = { 125 .write = mc13xxx_spi_write, 126 .read = mc13xxx_spi_read, 127 }; 128 129 static int mc13xxx_spi_probe(struct spi_device *spi) 130 { 131 struct mc13xxx *mc13xxx; 132 int ret; 133 134 mc13xxx = devm_kzalloc(&spi->dev, sizeof(*mc13xxx), GFP_KERNEL); 135 if (!mc13xxx) 136 return -ENOMEM; 137 138 dev_set_drvdata(&spi->dev, mc13xxx); 139 140 spi->mode = SPI_MODE_0 | SPI_CS_HIGH; 141 142 mc13xxx->irq = spi->irq; 143 144 spi->max_speed_hz = spi->max_speed_hz ? : 26000000; 145 ret = spi_setup(spi); 146 if (ret) 147 return ret; 148 149 mc13xxx->regmap = devm_regmap_init(&spi->dev, ®map_mc13xxx_bus, 150 &spi->dev, 151 &mc13xxx_regmap_spi_config); 152 if (IS_ERR(mc13xxx->regmap)) { 153 ret = PTR_ERR(mc13xxx->regmap); 154 dev_err(&spi->dev, "Failed to initialize regmap: %d\n", ret); 155 return ret; 156 } 157 158 if (spi->dev.of_node) { 159 const struct of_device_id *of_id = 160 of_match_device(mc13xxx_dt_ids, &spi->dev); 161 162 mc13xxx->variant = of_id->data; 163 } else { 164 const struct spi_device_id *id_entry = spi_get_device_id(spi); 165 166 mc13xxx->variant = (void *)id_entry->driver_data; 167 } 168 169 return mc13xxx_common_init(&spi->dev); 170 } 171 172 static int mc13xxx_spi_remove(struct spi_device *spi) 173 { 174 return mc13xxx_common_exit(&spi->dev); 175 } 176 177 static struct spi_driver mc13xxx_spi_driver = { 178 .id_table = mc13xxx_device_id, 179 .driver = { 180 .name = "mc13xxx", 181 .of_match_table = mc13xxx_dt_ids, 182 }, 183 .probe = mc13xxx_spi_probe, 184 .remove = mc13xxx_spi_remove, 185 }; 186 187 static int __init mc13xxx_init(void) 188 { 189 return spi_register_driver(&mc13xxx_spi_driver); 190 } 191 subsys_initcall(mc13xxx_init); 192 193 static void __exit mc13xxx_exit(void) 194 { 195 spi_unregister_driver(&mc13xxx_spi_driver); 196 } 197 module_exit(mc13xxx_exit); 198 199 MODULE_DESCRIPTION("Core driver for Freescale MC13XXX PMIC"); 200 MODULE_AUTHOR("Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>"); 201 MODULE_LICENSE("GPL v2"); 202