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