OpenWrt – Rev 4
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/*
* SPI driver for the CPLD chip on the Mikrotik RB4xx boards
*
* Copyright (C) 2010 Gabor Juhos <juhosg@openwrt.org>
*
* 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 <linux/types.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/bitops.h>
#include <linux/spi/spi.h>
#include <linux/gpio.h>
#include <linux/slab.h>
#include <linux/version.h>
#include <asm/mach-ath79/rb4xx_cpld.h>
#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;
#if LINUX_VERSION_CODE < KERNEL_VERSION(4,5,0)
cpld->chip.dev = &cpld->spi->dev;
#else
cpld->chip.parent = &cpld->spi->dev;
#endif
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 <juhosg@openwrt.org>");
MODULE_LICENSE("GPL v2");