diff options
Diffstat (limited to 'drivers/mfd/stmpe-spi.c')
-rw-r--r-- | drivers/mfd/stmpe-spi.c | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/drivers/mfd/stmpe-spi.c b/drivers/mfd/stmpe-spi.c new file mode 100644 index 000000000000..53efce4fe294 --- /dev/null +++ b/drivers/mfd/stmpe-spi.c @@ -0,0 +1,148 @@ +/* + * 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.kumar@st.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 __devinit +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 __devexit stmpe_spi_remove(struct spi_device *spi) +{ + struct stmpe *stmpe = dev_get_drvdata(&spi->dev); + + return stmpe_remove(stmpe); +} + +static const struct spi_device_id stmpe_spi_id[] = { + { "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", + .bus = &spi_bus_type, + .owner = THIS_MODULE, +#ifdef CONFIG_PM + .pm = &stmpe_dev_pm_ops, +#endif + }, + .probe = stmpe_spi_probe, + .remove = __devexit_p(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.kumar@st.com>"); |