1 /* 2 * AD7879/AD7889 touchscreen (SPI bus) 3 * 4 * Copyright (C) 2008-2010 Michael Hennerich, Analog Devices Inc. 5 * 6 * Licensed under the GPL-2 or later. 7 */ 8 9 #include <linux/input.h> /* BUS_SPI */ 10 #include <linux/pm.h> 11 #include <linux/spi/spi.h> 12 #include <linux/module.h> 13 #include <linux/of.h> 14 #include <linux/regmap.h> 15 16 #include "ad7879.h" 17 18 #define AD7879_DEVID 0x7A /* AD7879/AD7889 */ 19 20 #define MAX_SPI_FREQ_HZ 5000000 21 22 #define AD7879_CMD_MAGIC 0xE0 23 #define AD7879_CMD_READ BIT(2) 24 25 static const struct regmap_config ad7879_spi_regmap_config = { 26 .reg_bits = 16, 27 .val_bits = 16, 28 .max_register = 15, 29 .read_flag_mask = AD7879_CMD_MAGIC | AD7879_CMD_READ, 30 .write_flag_mask = AD7879_CMD_MAGIC, 31 }; 32 33 static int ad7879_spi_probe(struct spi_device *spi) 34 { 35 struct ad7879 *ts; 36 struct regmap *regmap; 37 int err; 38 39 /* don't exceed max specified SPI CLK frequency */ 40 if (spi->max_speed_hz > MAX_SPI_FREQ_HZ) { 41 dev_err(&spi->dev, "SPI CLK %d Hz?\n", spi->max_speed_hz); 42 return -EINVAL; 43 } 44 45 spi->bits_per_word = 16; 46 err = spi_setup(spi); 47 if (err) { 48 dev_dbg(&spi->dev, "spi master doesn't support 16 bits/word\n"); 49 return err; 50 } 51 52 regmap = devm_regmap_init_spi(spi, &ad7879_spi_regmap_config); 53 if (IS_ERR(regmap)) 54 return PTR_ERR(regmap); 55 56 ts = ad7879_probe(&spi->dev, regmap, spi->irq, BUS_SPI, AD7879_DEVID); 57 if (IS_ERR(ts)) 58 return PTR_ERR(ts); 59 60 spi_set_drvdata(spi, ts); 61 62 return 0; 63 } 64 65 static int ad7879_spi_remove(struct spi_device *spi) 66 { 67 struct ad7879 *ts = spi_get_drvdata(spi); 68 69 ad7879_remove(ts); 70 71 return 0; 72 } 73 74 #ifdef CONFIG_OF 75 static const struct of_device_id ad7879_spi_dt_ids[] = { 76 { .compatible = "adi,ad7879", }, 77 { } 78 }; 79 MODULE_DEVICE_TABLE(of, ad7879_spi_dt_ids); 80 #endif 81 82 static struct spi_driver ad7879_spi_driver = { 83 .driver = { 84 .name = "ad7879", 85 .pm = &ad7879_pm_ops, 86 .of_match_table = of_match_ptr(ad7879_spi_dt_ids), 87 }, 88 .probe = ad7879_spi_probe, 89 .remove = ad7879_spi_remove, 90 }; 91 92 module_spi_driver(ad7879_spi_driver); 93 94 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>"); 95 MODULE_DESCRIPTION("AD7879(-1) touchscreen SPI bus driver"); 96 MODULE_LICENSE("GPL"); 97 MODULE_ALIAS("spi:ad7879"); 98