/* * Copyright 2009-2010 Pengutronix * Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de> * * loosely based on an earlier driver that has * Copyright 2009 Pengutronix, Sascha Hauer <s.hauer@pengutronix.de> * * This program is free software; you can redistribute it and/or modify it under * the terms of the GNU General Public License version 2 as published by the * Free Software Foundation. */ #include <linux/slab.h> #include <linux/module.h> #include <linux/platform_device.h> #include <linux/mutex.h> #include <linux/interrupt.h> #include <linux/mfd/core.h> #include <linux/mfd/mc13xxx.h> #include <linux/of.h> #include <linux/of_device.h> #include <linux/of_gpio.h> #include <linux/err.h> #include <linux/spi/spi.h> #include "mc13xxx.h" static const struct spi_device_id mc13xxx_device_id[] = { { .name = "mc13783", .driver_data = (kernel_ulong_t)&mc13xxx_variant_mc13783, }, { .name = "mc13892", .driver_data = (kernel_ulong_t)&mc13xxx_variant_mc13892, }, { .name = "mc34708", .driver_data = (kernel_ulong_t)&mc13xxx_variant_mc34708, }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(spi, mc13xxx_device_id); static const struct of_device_id mc13xxx_dt_ids[] = { { .compatible = "fsl,mc13783", .data = &mc13xxx_variant_mc13783, }, { .compatible = "fsl,mc13892", .data = &mc13xxx_variant_mc13892, }, { .compatible = "fsl,mc34708", .data = &mc13xxx_variant_mc34708, }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, mc13xxx_dt_ids); static struct regmap_config mc13xxx_regmap_spi_config = { .reg_bits = 7, .pad_bits = 1, .val_bits = 24, .write_flag_mask = 0x80, .max_register = MC13XXX_NUMREGS, .cache_type = REGCACHE_NONE, .use_single_rw = 1, }; static int mc13xxx_spi_read(void *context, const void *reg, size_t reg_size, void *val, size_t val_size) { unsigned char w[4] = { *((unsigned char *) reg), 0, 0, 0}; unsigned char r[4]; unsigned char *p = val; struct device *dev = context; struct spi_device *spi = to_spi_device(dev); struct spi_transfer t = { .tx_buf = w, .rx_buf = r, .len = 4, }; struct spi_message m; int ret; if (val_size != 3 || reg_size != 1) return -ENOTSUPP; spi_message_init(&m); spi_message_add_tail(&t, &m); ret = spi_sync(spi, &m); memcpy(p, &r[1], 3); return ret; } static int mc13xxx_spi_write(void *context, const void *data, size_t count) { struct device *dev = context; struct spi_device *spi = to_spi_device(dev); if (count != 4) return -ENOTSUPP; return spi_write(spi, data, count); } /* * We cannot use regmap-spi generic bus implementation here. * The MC13783 chip will get corrupted if CS signal is deasserted * and on i.Mx31 SoC (the target SoC for MC13783 PMIC) the SPI controller * has the following errata (DSPhl22960): * "The CSPI negates SS when the FIFO becomes empty with * SSCTL= 0. Software cannot guarantee that the FIFO will not * drain because of higher priority interrupts and the * non-realtime characteristics of the operating system. As a * result, the SS will negate before all of the data has been * transferred to/from the peripheral." * We workaround this by accessing the SPI controller with a * single transfert. */ static struct regmap_bus regmap_mc13xxx_bus = { .write = mc13xxx_spi_write, .read = mc13xxx_spi_read, }; static int mc13xxx_spi_probe(struct spi_device *spi) { struct mc13xxx *mc13xxx; struct mc13xxx_platform_data *pdata = dev_get_platdata(&spi->dev); int ret; mc13xxx = devm_kzalloc(&spi->dev, sizeof(*mc13xxx), GFP_KERNEL); if (!mc13xxx) return -ENOMEM; dev_set_drvdata(&spi->dev, mc13xxx); spi->mode = SPI_MODE_0 | SPI_CS_HIGH; mc13xxx->dev = &spi->dev; mutex_init(&mc13xxx->lock); mc13xxx->regmap = devm_regmap_init(&spi->dev, ®map_mc13xxx_bus, &spi->dev, &mc13xxx_regmap_spi_config); if (IS_ERR(mc13xxx->regmap)) { ret = PTR_ERR(mc13xxx->regmap); dev_err(mc13xxx->dev, "Failed to initialize register map: %d\n", ret); dev_set_drvdata(&spi->dev, NULL); return ret; } if (spi->dev.of_node) { const struct of_device_id *of_id = of_match_device(mc13xxx_dt_ids, &spi->dev); mc13xxx->variant = of_id->data; } else { const struct spi_device_id *id_entry = spi_get_device_id(spi); mc13xxx->variant = (void *)id_entry->driver_data; } return mc13xxx_common_init(mc13xxx, pdata, spi->irq); } static int mc13xxx_spi_remove(struct spi_device *spi) { struct mc13xxx *mc13xxx = dev_get_drvdata(&spi->dev); mc13xxx_common_cleanup(mc13xxx); return 0; } static struct spi_driver mc13xxx_spi_driver = { .id_table = mc13xxx_device_id, .driver = { .name = "mc13xxx", .owner = THIS_MODULE, .of_match_table = mc13xxx_dt_ids, }, .probe = mc13xxx_spi_probe, .remove = mc13xxx_spi_remove, }; static int __init mc13xxx_init(void) { return spi_register_driver(&mc13xxx_spi_driver); } subsys_initcall(mc13xxx_init); static void __exit mc13xxx_exit(void) { spi_unregister_driver(&mc13xxx_spi_driver); } module_exit(mc13xxx_exit); MODULE_DESCRIPTION("Core driver for Freescale MC13XXX PMIC"); MODULE_AUTHOR("Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>"); MODULE_LICENSE("GPL v2");