/* * SPI driver for the CPLD chip on the Mikrotik RB4xx boards * * Copyright (C) 2010 Gabor Juhos * * This file was based on the patches for Linux 2.6.27.39 published by * MikroTik for their RouterBoard 4xx series devices. * * 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 #include #include #include #include #include #include #include #include #include #include #define DRV_NAME "spi-rb4xx-cpld" #define DRV_DESC "RB4xx CPLD driver" #define DRV_VERSION "0.1.0" #define CPLD_CMD_WRITE_NAND 0x08 /* send cmd, n x send data, send indle */ #define CPLD_CMD_WRITE_CFG 0x09 /* send cmd, n x send cfg */ #define CPLD_CMD_READ_NAND 0x0a /* send cmd, send idle, n x read data */ #define CPLD_CMD_READ_FAST 0x0b /* send cmd, 4 x idle, n x read data */ #define CPLD_CMD_LED5_ON 0x0c /* send cmd */ #define CPLD_CMD_LED5_OFF 0x0d /* send cmd */ struct rb4xx_cpld { struct spi_device *spi; struct mutex lock; struct gpio_chip chip; unsigned int config; }; static struct rb4xx_cpld *rb4xx_cpld; static inline struct rb4xx_cpld *gpio_to_cpld(struct gpio_chip *chip) { return container_of(chip, struct rb4xx_cpld, chip); } static int rb4xx_cpld_write_cmd(struct rb4xx_cpld *cpld, unsigned char cmd) { struct spi_transfer t[1]; struct spi_message m; unsigned char tx_buf[1]; int err; spi_message_init(&m); memset(&t, 0, sizeof(t)); t[0].tx_buf = tx_buf; t[0].len = sizeof(tx_buf); spi_message_add_tail(&t[0], &m); tx_buf[0] = cmd; err = spi_sync(cpld->spi, &m); return err; } static int rb4xx_cpld_write_cfg(struct rb4xx_cpld *cpld, unsigned char config) { struct spi_transfer t[1]; struct spi_message m; unsigned char cmd[2]; int err; spi_message_init(&m); memset(&t, 0, sizeof(t)); t[0].tx_buf = cmd; t[0].len = sizeof(cmd); spi_message_add_tail(&t[0], &m); cmd[0] = CPLD_CMD_WRITE_CFG; cmd[1] = config; err = spi_sync(cpld->spi, &m); return err; } static int __rb4xx_cpld_change_cfg(struct rb4xx_cpld *cpld, unsigned mask, unsigned value) { unsigned int config; int err; config = cpld->config & ~mask; config |= value; if ((cpld->config ^ config) & 0xff) { err = rb4xx_cpld_write_cfg(cpld, config); if (err) return err; } if ((cpld->config ^ config) & CPLD_CFG_nLED5) { err = rb4xx_cpld_write_cmd(cpld, (value) ? CPLD_CMD_LED5_ON : CPLD_CMD_LED5_OFF); if (err) return err; } cpld->config = config; return 0; } int rb4xx_cpld_change_cfg(unsigned mask, unsigned value) { int ret; if (rb4xx_cpld == NULL) return -ENODEV; mutex_lock(&rb4xx_cpld->lock); ret = __rb4xx_cpld_change_cfg(rb4xx_cpld, mask, value); mutex_unlock(&rb4xx_cpld->lock); return ret; } EXPORT_SYMBOL_GPL(rb4xx_cpld_change_cfg); int rb4xx_cpld_read(unsigned char *rx_buf, unsigned count) { static const unsigned char cmd[2] = { CPLD_CMD_READ_NAND, 0 }; struct spi_transfer t[2] = { { .tx_buf = &cmd, .len = 2, }, { .rx_buf = rx_buf, .len = count, }, }; struct spi_message m; if (rb4xx_cpld == NULL) return -ENODEV; spi_message_init(&m); spi_message_add_tail(&t[0], &m); spi_message_add_tail(&t[1], &m); return spi_sync(rb4xx_cpld->spi, &m); } EXPORT_SYMBOL_GPL(rb4xx_cpld_read); int rb4xx_cpld_write(const unsigned char *buf, unsigned count) { static const unsigned char cmd = CPLD_CMD_WRITE_NAND; struct spi_transfer t[3] = { { .tx_buf = &cmd, .len = 1, }, { .tx_buf = buf, .len = count, .tx_nbits = SPI_NBITS_DUAL, }, { .len = 1, .tx_nbits = SPI_NBITS_DUAL, }, }; struct spi_message m; if (rb4xx_cpld == NULL) return -ENODEV; spi_message_init(&m); spi_message_add_tail(&t[0], &m); spi_message_add_tail(&t[1], &m); spi_message_add_tail(&t[2], &m); return spi_sync(rb4xx_cpld->spi, &m); } EXPORT_SYMBOL_GPL(rb4xx_cpld_write); static int rb4xx_cpld_gpio_get(struct gpio_chip *chip, unsigned offset) { struct rb4xx_cpld *cpld = gpio_to_cpld(chip); int ret; mutex_lock(&cpld->lock); ret = (cpld->config >> offset) & 1; mutex_unlock(&cpld->lock); return ret; } static void rb4xx_cpld_gpio_set(struct gpio_chip *chip, unsigned offset, int value) { struct rb4xx_cpld *cpld = gpio_to_cpld(chip); mutex_lock(&cpld->lock); __rb4xx_cpld_change_cfg(cpld, (1 << offset), !!value << offset); mutex_unlock(&cpld->lock); } static int rb4xx_cpld_gpio_direction_input(struct gpio_chip *chip, unsigned offset) { return -EOPNOTSUPP; } static int rb4xx_cpld_gpio_direction_output(struct gpio_chip *chip, unsigned offset, int value) { struct rb4xx_cpld *cpld = gpio_to_cpld(chip); int ret; mutex_lock(&cpld->lock); ret = __rb4xx_cpld_change_cfg(cpld, (1 << offset), !!value << offset); mutex_unlock(&cpld->lock); return ret; } static int rb4xx_cpld_gpio_init(struct rb4xx_cpld *cpld, unsigned int base) { int err; /* init config */ cpld->config = CPLD_CFG_nLED1 | CPLD_CFG_nLED2 | CPLD_CFG_nLED3 | CPLD_CFG_nLED4 | CPLD_CFG_nCE; rb4xx_cpld_write_cfg(cpld, cpld->config); /* setup GPIO chip */ cpld->chip.label = DRV_NAME; cpld->chip.get = rb4xx_cpld_gpio_get; cpld->chip.set = rb4xx_cpld_gpio_set; cpld->chip.direction_input = rb4xx_cpld_gpio_direction_input; cpld->chip.direction_output = rb4xx_cpld_gpio_direction_output; cpld->chip.base = base; cpld->chip.ngpio = CPLD_NUM_GPIOS; cpld->chip.can_sleep = 1; cpld->chip.dev = &cpld->spi->dev; cpld->chip.owner = THIS_MODULE; err = gpiochip_add(&cpld->chip); if (err) dev_err(&cpld->spi->dev, "adding GPIO chip failed, err=%d\n", err); return err; } static int rb4xx_cpld_probe(struct spi_device *spi) { struct rb4xx_cpld *cpld; struct rb4xx_cpld_platform_data *pdata; int err; pdata = spi->dev.platform_data; if (!pdata) { dev_dbg(&spi->dev, "no platform data\n"); return -EINVAL; } cpld = kzalloc(sizeof(*cpld), GFP_KERNEL); if (!cpld) { dev_err(&spi->dev, "no memory for private data\n"); return -ENOMEM; } mutex_init(&cpld->lock); cpld->spi = spi_dev_get(spi); dev_set_drvdata(&spi->dev, cpld); spi->mode = SPI_MODE_0 | SPI_TX_DUAL; spi->bits_per_word = 8; err = spi_setup(spi); if (err) { dev_err(&spi->dev, "spi_setup failed, err=%d\n", err); goto err_drvdata; } err = rb4xx_cpld_gpio_init(cpld, pdata->gpio_base); if (err) goto err_drvdata; rb4xx_cpld = cpld; return 0; err_drvdata: dev_set_drvdata(&spi->dev, NULL); kfree(cpld); return err; } static int rb4xx_cpld_remove(struct spi_device *spi) { struct rb4xx_cpld *cpld; rb4xx_cpld = NULL; cpld = dev_get_drvdata(&spi->dev); dev_set_drvdata(&spi->dev, NULL); kfree(cpld); return 0; } static struct spi_driver rb4xx_cpld_driver = { .driver = { .name = DRV_NAME, .bus = &spi_bus_type, .owner = THIS_MODULE, }, .probe = rb4xx_cpld_probe, .remove = rb4xx_cpld_remove, }; static int __init rb4xx_cpld_init(void) { return spi_register_driver(&rb4xx_cpld_driver); } module_init(rb4xx_cpld_init); static void __exit rb4xx_cpld_exit(void) { spi_unregister_driver(&rb4xx_cpld_driver); } module_exit(rb4xx_cpld_exit); MODULE_DESCRIPTION(DRV_DESC); MODULE_VERSION(DRV_VERSION); MODULE_AUTHOR("Gabor Juhos "); MODULE_LICENSE("GPL v2");