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/module.h> 12 #include <linux/platform_device.h> 13 #include <linux/interrupt.h> 14 #include <linux/mfd/core.h> 15 #include <linux/mfd/mc13xxx.h> 16 #include <linux/of.h> 17 #include <linux/of_device.h> 18 #include <linux/err.h> 19 #include <linux/spi/spi.h> 20 21 #include "mc13xxx.h" 22 23 static const struct spi_device_id mc13xxx_device_id[] = { 24 { 25 .name = "mc13783", 26 .driver_data = (kernel_ulong_t)&mc13xxx_variant_mc13783, 27 }, { 28 .name = "mc13892", 29 .driver_data = (kernel_ulong_t)&mc13xxx_variant_mc13892, 30 }, { 31 .name = "mc34708", 32 .driver_data = (kernel_ulong_t)&mc13xxx_variant_mc34708, 33 }, { 34 /* sentinel */ 35 } 36 }; 37 MODULE_DEVICE_TABLE(spi, mc13xxx_device_id); 38 39 static const struct of_device_id mc13xxx_dt_ids[] = { 40 { .compatible = "fsl,mc13783", .data = &mc13xxx_variant_mc13783, }, 41 { .compatible = "fsl,mc13892", .data = &mc13xxx_variant_mc13892, }, 42 { .compatible = "fsl,mc34708", .data = &mc13xxx_variant_mc34708, }, 43 { /* sentinel */ } 44 }; 45 MODULE_DEVICE_TABLE(of, mc13xxx_dt_ids); 46 47 static const struct regmap_config mc13xxx_regmap_spi_config = { 48 .reg_bits = 7, 49 .pad_bits = 1, 50 .val_bits = 24, 51 .write_flag_mask = 0x80, 52 53 .max_register = MC13XXX_NUMREGS, 54 55 .cache_type = REGCACHE_NONE, 56 .use_single_read = true, 57 .use_single_write = true, 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 const char *reg = data; 94 95 if (count != 4) 96 return -ENOTSUPP; 97 98 /* include errata fix for spi audio problems */ 99 if (*reg == MC13783_AUDIO_CODEC || *reg == MC13783_AUDIO_DAC) 100 spi_write(spi, data, count); 101 102 return spi_write(spi, data, count); 103 } 104 105 /* 106 * We cannot use regmap-spi generic bus implementation here. 107 * The MC13783 chip will get corrupted if CS signal is deasserted 108 * and on i.Mx31 SoC (the target SoC for MC13783 PMIC) the SPI controller 109 * has the following errata (DSPhl22960): 110 * "The CSPI negates SS when the FIFO becomes empty with 111 * SSCTL= 0. Software cannot guarantee that the FIFO will not 112 * drain because of higher priority interrupts and the 113 * non-realtime characteristics of the operating system. As a 114 * result, the SS will negate before all of the data has been 115 * transferred to/from the peripheral." 116 * We workaround this by accessing the SPI controller with a 117 * single transfer. 118 */ 119 120 static struct regmap_bus regmap_mc13xxx_bus = { 121 .write = mc13xxx_spi_write, 122 .read = mc13xxx_spi_read, 123 }; 124 125 static int mc13xxx_spi_probe(struct spi_device *spi) 126 { 127 struct mc13xxx *mc13xxx; 128 int ret; 129 130 mc13xxx = devm_kzalloc(&spi->dev, sizeof(*mc13xxx), GFP_KERNEL); 131 if (!mc13xxx) 132 return -ENOMEM; 133 134 dev_set_drvdata(&spi->dev, mc13xxx); 135 136 spi->mode = SPI_MODE_0 | SPI_CS_HIGH; 137 138 mc13xxx->irq = spi->irq; 139 140 spi->max_speed_hz = spi->max_speed_hz ? : 26000000; 141 ret = spi_setup(spi); 142 if (ret) 143 return ret; 144 145 mc13xxx->regmap = devm_regmap_init(&spi->dev, ®map_mc13xxx_bus, 146 &spi->dev, 147 &mc13xxx_regmap_spi_config); 148 if (IS_ERR(mc13xxx->regmap)) { 149 ret = PTR_ERR(mc13xxx->regmap); 150 dev_err(&spi->dev, "Failed to initialize regmap: %d\n", ret); 151 return ret; 152 } 153 154 if (spi->dev.of_node) { 155 const struct of_device_id *of_id = 156 of_match_device(mc13xxx_dt_ids, &spi->dev); 157 158 mc13xxx->variant = of_id->data; 159 } else { 160 const struct spi_device_id *id_entry = spi_get_device_id(spi); 161 162 mc13xxx->variant = (void *)id_entry->driver_data; 163 } 164 165 return mc13xxx_common_init(&spi->dev); 166 } 167 168 static void mc13xxx_spi_remove(struct spi_device *spi) 169 { 170 mc13xxx_common_exit(&spi->dev); 171 } 172 173 static struct spi_driver mc13xxx_spi_driver = { 174 .id_table = mc13xxx_device_id, 175 .driver = { 176 .name = "mc13xxx", 177 .of_match_table = mc13xxx_dt_ids, 178 }, 179 .probe = mc13xxx_spi_probe, 180 .remove = mc13xxx_spi_remove, 181 }; 182 183 static int __init mc13xxx_init(void) 184 { 185 return spi_register_driver(&mc13xxx_spi_driver); 186 } 187 subsys_initcall(mc13xxx_init); 188 189 static void __exit mc13xxx_exit(void) 190 { 191 spi_unregister_driver(&mc13xxx_spi_driver); 192 } 193 module_exit(mc13xxx_exit); 194 195 MODULE_DESCRIPTION("Core driver for Freescale MC13XXX PMIC"); 196 MODULE_AUTHOR("Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>"); 197 MODULE_LICENSE("GPL v2"); 198