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/mutex.h> 17 #include <linux/interrupt.h> 18 #include <linux/mfd/core.h> 19 #include <linux/mfd/mc13xxx.h> 20 #include <linux/of.h> 21 #include <linux/of_device.h> 22 #include <linux/of_gpio.h> 23 #include <linux/err.h> 24 #include <linux/spi/spi.h> 25 26 #include "mc13xxx.h" 27 28 static const struct spi_device_id mc13xxx_device_id[] = { 29 { 30 .name = "mc13783", 31 .driver_data = MC13XXX_ID_MC13783, 32 }, { 33 .name = "mc13892", 34 .driver_data = MC13XXX_ID_MC13892, 35 }, { 36 /* sentinel */ 37 } 38 }; 39 MODULE_DEVICE_TABLE(spi, mc13xxx_device_id); 40 41 static const struct of_device_id mc13xxx_dt_ids[] = { 42 { .compatible = "fsl,mc13783", .data = (void *) MC13XXX_ID_MC13783, }, 43 { .compatible = "fsl,mc13892", .data = (void *) MC13XXX_ID_MC13892, }, 44 { /* sentinel */ } 45 }; 46 MODULE_DEVICE_TABLE(of, mc13xxx_dt_ids); 47 48 static struct regmap_config mc13xxx_regmap_spi_config = { 49 .reg_bits = 7, 50 .pad_bits = 1, 51 .val_bits = 24, 52 .write_flag_mask = 0x80, 53 54 .max_register = MC13XXX_NUMREGS, 55 56 .cache_type = REGCACHE_NONE, 57 .use_single_rw = 1, 58 }; 59 60 static int mc13xxx_spi_read(void *context, const void *reg, size_t reg_size, 61 void *val, size_t val_size) 62 { 63 unsigned char w[4] = { *((unsigned char *) reg), 0, 0, 0}; 64 unsigned char r[4]; 65 unsigned char *p = val; 66 struct device *dev = context; 67 struct spi_device *spi = to_spi_device(dev); 68 struct spi_transfer t = { 69 .tx_buf = w, 70 .rx_buf = r, 71 .len = 4, 72 }; 73 74 struct spi_message m; 75 int ret; 76 77 if (val_size != 3 || reg_size != 1) 78 return -ENOTSUPP; 79 80 spi_message_init(&m); 81 spi_message_add_tail(&t, &m); 82 ret = spi_sync(spi, &m); 83 84 memcpy(p, &r[1], 3); 85 86 return ret; 87 } 88 89 static int mc13xxx_spi_write(void *context, const void *data, size_t count) 90 { 91 struct device *dev = context; 92 struct spi_device *spi = to_spi_device(dev); 93 94 if (count != 4) 95 return -ENOTSUPP; 96 97 return spi_write(spi, data, count); 98 } 99 100 /* 101 * We cannot use regmap-spi generic bus implementation here. 102 * The MC13783 chip will get corrupted if CS signal is deasserted 103 * and on i.Mx31 SoC (the target SoC for MC13783 PMIC) the SPI controller 104 * has the following errata (DSPhl22960): 105 * "The CSPI negates SS when the FIFO becomes empty with 106 * SSCTL= 0. Software cannot guarantee that the FIFO will not 107 * drain because of higher priority interrupts and the 108 * non-realtime characteristics of the operating system. As a 109 * result, the SS will negate before all of the data has been 110 * transferred to/from the peripheral." 111 * We workaround this by accessing the SPI controller with a 112 * single transfert. 113 */ 114 115 static struct regmap_bus regmap_mc13xxx_bus = { 116 .write = mc13xxx_spi_write, 117 .read = mc13xxx_spi_read, 118 }; 119 120 static int mc13xxx_spi_probe(struct spi_device *spi) 121 { 122 struct mc13xxx *mc13xxx; 123 struct mc13xxx_platform_data *pdata = dev_get_platdata(&spi->dev); 124 int ret; 125 126 mc13xxx = devm_kzalloc(&spi->dev, sizeof(*mc13xxx), GFP_KERNEL); 127 if (!mc13xxx) 128 return -ENOMEM; 129 130 dev_set_drvdata(&spi->dev, mc13xxx); 131 spi->mode = SPI_MODE_0 | SPI_CS_HIGH; 132 133 mc13xxx->dev = &spi->dev; 134 mutex_init(&mc13xxx->lock); 135 136 mc13xxx->regmap = devm_regmap_init(&spi->dev, ®map_mc13xxx_bus, 137 &spi->dev, 138 &mc13xxx_regmap_spi_config); 139 if (IS_ERR(mc13xxx->regmap)) { 140 ret = PTR_ERR(mc13xxx->regmap); 141 dev_err(mc13xxx->dev, "Failed to initialize register map: %d\n", 142 ret); 143 dev_set_drvdata(&spi->dev, NULL); 144 return ret; 145 } 146 147 ret = mc13xxx_common_init(mc13xxx, pdata, spi->irq); 148 149 if (ret) { 150 dev_set_drvdata(&spi->dev, NULL); 151 } else { 152 const struct spi_device_id *devid = 153 spi_get_device_id(spi); 154 if (!devid || devid->driver_data != mc13xxx->ictype) 155 dev_warn(mc13xxx->dev, 156 "device id doesn't match auto detection!\n"); 157 } 158 159 return ret; 160 } 161 162 static int __devexit mc13xxx_spi_remove(struct spi_device *spi) 163 { 164 struct mc13xxx *mc13xxx = dev_get_drvdata(&spi->dev); 165 166 mc13xxx_common_cleanup(mc13xxx); 167 168 return 0; 169 } 170 171 static struct spi_driver mc13xxx_spi_driver = { 172 .id_table = mc13xxx_device_id, 173 .driver = { 174 .name = "mc13xxx", 175 .owner = THIS_MODULE, 176 .of_match_table = mc13xxx_dt_ids, 177 }, 178 .probe = mc13xxx_spi_probe, 179 .remove = __devexit_p(mc13xxx_spi_remove), 180 }; 181 182 static int __init mc13xxx_init(void) 183 { 184 return spi_register_driver(&mc13xxx_spi_driver); 185 } 186 subsys_initcall(mc13xxx_init); 187 188 static void __exit mc13xxx_exit(void) 189 { 190 spi_unregister_driver(&mc13xxx_spi_driver); 191 } 192 module_exit(mc13xxx_exit); 193 194 MODULE_DESCRIPTION("Core driver for Freescale MC13XXX PMIC"); 195 MODULE_AUTHOR("Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>"); 196 MODULE_LICENSE("GPL v2"); 197