text: /*
   * ST Microelectronics MFD: stmpe's spi client specific driver
   *
   * Copyright (C) ST Microelectronics SA 2011
   *
   * License Terms: GNU General Public License, version 2
   * Author: Viresh Kumar <viresh.linux@gmail.com> for ST Microelectronics
   */
  
  #include <linux/spi/spi.h>
  #include <linux/interrupt.h>
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/types.h>
  #include "stmpe.h"
  
  #define READ_CMD	(1 << 7)
  
  static int spi_reg_read(struct stmpe *stmpe, u8 reg)
  {
  	struct spi_device *spi = stmpe->client;
  	int status = spi_w8r16(spi, reg | READ_CMD);
  
  	return (status < 0) ? status : status >> 8;
  }
  
  static int spi_reg_write(struct stmpe *stmpe, u8 reg, u8 val)
  {
  	struct spi_device *spi = stmpe->client;
  	u16 cmd = (val << 8) | reg;
  
  	return spi_write(spi, (const u8 *)&cmd, 2);
  }
  
  static int spi_block_read(struct stmpe *stmpe, u8 reg, u8 length, u8 *values)
  {
  	int ret, i;
  
  	for (i = 0; i < length; i++) {
  		ret = spi_reg_read(stmpe, reg + i);
  		if (ret < 0)
  			return ret;
  		*(values + i) = ret;
  	}
  
  	return 0;
  }
  
  static int spi_block_write(struct stmpe *stmpe, u8 reg, u8 length,
  		const u8 *values)
  {
  	int ret = 0, i;
  
  	for (i = length; i > 0; i--, reg++) {
  		ret = spi_reg_write(stmpe, reg, *(values + i - 1));
  		if (ret < 0)
  			return ret;
  	}
  
  	return ret;
  }
  
  static void spi_init(struct stmpe *stmpe)
  {
  	struct spi_device *spi = stmpe->client;
  
  	spi->bits_per_word = 8;
  
  	/* This register is only present for stmpe811 */
  	if (stmpe->variant->id_val == 0x0811)
  		spi_reg_write(stmpe, STMPE811_REG_SPI_CFG, spi->mode);
  
  	if (spi_setup(spi) < 0)
  		dev_dbg(&spi->dev, "spi_setup failed\n");
  }
  
  static struct stmpe_client_info spi_ci = {
  	.read_byte = spi_reg_read,
  	.write_byte = spi_reg_write,
  	.read_block = spi_block_read,
  	.write_block = spi_block_write,
  	.init = spi_init,
  };
  
  static int
  stmpe_spi_probe(struct spi_device *spi)
  {
  	const struct spi_device_id *id = spi_get_device_id(spi);
  
  	/* don't exceed max specified rate - 1MHz - Limitation of STMPE */
  	if (spi->max_speed_hz > 1000000) {
  		dev_dbg(&spi->dev, "f(sample) %d KHz?\n",
  				(spi->max_speed_hz/1000));
  		return -EINVAL;
  	}
  
  	spi_ci.irq = spi->irq;
  	spi_ci.client = spi;
  	spi_ci.dev = &spi->dev;
  
  	return stmpe_probe(&spi_ci, id->driver_data);
  }
  
  static int stmpe_spi_remove(struct spi_device *spi)
  {
  	struct stmpe *stmpe = spi_get_drvdata(spi);
  
  	return stmpe_remove(stmpe);
  }
  
  static const struct spi_device_id stmpe_spi_id[] = {
  	{ "stmpe610", STMPE610 },
  	{ "stmpe801", STMPE801 },
  	{ "stmpe811", STMPE811 },
  	{ "stmpe1601", STMPE1601 },
  	{ "stmpe2401", STMPE2401 },
  	{ "stmpe2403", STMPE2403 },
  	{ }
  };
  MODULE_DEVICE_TABLE(spi, stmpe_id);
  
  static struct spi_driver stmpe_spi_driver = {
  	.driver = {
  		.name	= "stmpe-spi",
  		.owner	= THIS_MODULE,
  #ifdef CONFIG_PM
  		.pm	= &stmpe_dev_pm_ops,
  #endif
  	},
  	.probe		= stmpe_spi_probe,
  	.remove		= stmpe_spi_remove,
  	.id_table	= stmpe_spi_id,
  };
  
  static int __init stmpe_init(void)
  {
  	return spi_register_driver(&stmpe_spi_driver);
  }
  subsys_initcall(stmpe_init);
  
  static void __exit stmpe_exit(void)
  {
  	spi_unregister_driver(&stmpe_spi_driver);
  }
  module_exit(stmpe_exit);
  
  MODULE_LICENSE("GPL v2");
  MODULE_DESCRIPTION("STMPE MFD SPI Interface Driver");
  MODULE_AUTHOR("Viresh Kumar <viresh.linux@gmail.com>");
  