/*
   * 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/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);
  	const char *reg = data;
  
  	if (count != 4)
  		return -ENOTSUPP;
  
  	/* include errata fix for spi audio problems */
  	if (*reg == MC13783_AUDIO_CODEC || *reg == MC13783_AUDIO_DAC)
  		spi_write(spi, data, count);
  
  	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;
  	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->irq = spi->irq;
  
  	mc13xxx->regmap = devm_regmap_init(&spi->dev, &regmap_mc13xxx_bus,
  					   &spi->dev,
  					   &mc13xxx_regmap_spi_config);
  	if (IS_ERR(mc13xxx->regmap)) {
  		ret = PTR_ERR(mc13xxx->regmap);
  		dev_err(&spi->dev, "Failed to initialize regmap: %d
  ", ret);
  		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(&spi->dev);
  }
  
  static int mc13xxx_spi_remove(struct spi_device *spi)
  {
  	return mc13xxx_common_exit(&spi->dev);
  }
  
  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");