small tool for controlling digital RF step atteunators attached via linux GPIOs
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/*
* GPIO driver for NCT5104D
*
* Author: Tasanakorn Phaipool <tasanakorn@gmail.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/gpio.h>
#define DRVNAME "gpio-nct5104d"
/*
* Super-I/O registers
*/
#define SIO_LDSEL 0x07 /* Logical device select */
#define SIO_CHIPID 0x20 /* Chaip ID (2 bytes) */
#define SIO_GPIO_ENABLE 0x30 /* GPIO enable */
#define SIO_GPIO1_MODE 0xE0 /* GPIO1 Mode OpenDrain/Push-Pull */
#define SIO_GPIO2_MODE 0xE1 /* GPIO2 Mode OpenDrain/Push-Pull */
#define SIO_LD_GPIO 0x07 /* GPIO logical device */
#define SIO_LD_GPIO_MODE 0x0F /* GPIO mode control device */
#define SIO_UNLOCK_KEY 0x87 /* Key to enable Super-I/O */
#define SIO_LOCK_KEY 0xAA /* Key to disable Super-I/O */
#define SIO_NCT5104D_ID 0x1061 /* Chip ID */
#define SIO_PCENGINES_APU_NCT5104D_ID 0xc452 /* Chip ID */
enum chips { nct5104d };
static const char * const nct5104d_names[] = {
"nct5104d"
};
struct nct5104d_sio {
int addr;
enum chips type;
};
struct nct5104d_gpio_bank {
struct gpio_chip chip;
unsigned int regbase;
struct nct5104d_gpio_data *data;
};
struct nct5104d_gpio_data {
struct nct5104d_sio *sio;
int nr_bank;
struct nct5104d_gpio_bank *bank;
};
/*
* Super-I/O functions.
*/
static inline int superio_inb(int base, int reg)
{
outb(reg, base);
return inb(base + 1);
}
static int superio_inw(int base, int reg)
{
int val;
outb(reg++, base);
val = inb(base + 1) << 8;
outb(reg, base);
val |= inb(base + 1);
return val;
}
static inline void superio_outb(int base, int reg, int val)
{
outb(reg, base);
outb(val, base + 1);
}
static inline int superio_enter(int base)
{
/* Don't step on other drivers' I/O space by accident. */
if (!request_muxed_region(base, 2, DRVNAME)) {
pr_err(DRVNAME "I/O address 0x%04x already in use\n", base);
return -EBUSY;
}
/* According to the datasheet the key must be send twice. */
outb(SIO_UNLOCK_KEY, base);
outb(SIO_UNLOCK_KEY, base);
return 0;
}
static inline void superio_select(int base, int ld)
{
outb(SIO_LDSEL, base);
outb(ld, base + 1);
}
static inline void superio_exit(int base)
{
outb(SIO_LOCK_KEY, base);
release_region(base, 2);
}
/*
* GPIO chip.
*/
static int nct5104d_gpio_direction_in(struct gpio_chip *chip, unsigned offset);
static int nct5104d_gpio_get(struct gpio_chip *chip, unsigned offset);
static int nct5104d_gpio_direction_out(struct gpio_chip *chip,
unsigned offset, int value);
static void nct5104d_gpio_set(struct gpio_chip *chip, unsigned offset, int value);
#define NCT5104D_GPIO_BANK(_base, _ngpio, _regbase) \
{ \
.chip = { \
.label = DRVNAME, \
.owner = THIS_MODULE, \
.direction_input = nct5104d_gpio_direction_in, \
.get = nct5104d_gpio_get, \
.direction_output = nct5104d_gpio_direction_out, \
.set = nct5104d_gpio_set, \
.base = _base, \
.ngpio = _ngpio, \
.can_sleep = true, \
}, \
.regbase = _regbase, \
}
#define gpio_dir(base) (base + 0)
#define gpio_data(base) (base + 1)
static struct nct5104d_gpio_bank nct5104d_gpio_bank[] = {
NCT5104D_GPIO_BANK(0 , 8, 0xE0),
NCT5104D_GPIO_BANK(10, 8, 0xE4)
};
static int nct5104d_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
{
int err;
struct nct5104d_gpio_bank *bank =
container_of(chip, struct nct5104d_gpio_bank, chip);
struct nct5104d_sio *sio = bank->data->sio;
u8 dir;
err = superio_enter(sio->addr);
if (err)
return err;
superio_select(sio->addr, SIO_LD_GPIO);
dir = superio_inb(sio->addr, gpio_dir(bank->regbase));
dir |= (1 << offset);
superio_outb(sio->addr, gpio_dir(bank->regbase), dir);
superio_exit(sio->addr);
return 0;
}
static int nct5104d_gpio_get(struct gpio_chip *chip, unsigned offset)
{
int err;
struct nct5104d_gpio_bank *bank =
container_of(chip, struct nct5104d_gpio_bank, chip);
struct nct5104d_sio *sio = bank->data->sio;
u8 data;
err = superio_enter(sio->addr);
if (err)
return err;
superio_select(sio->addr, SIO_LD_GPIO);
data = superio_inb(sio->addr, gpio_data(bank->regbase));
superio_exit(sio->addr);
return !!(data & 1 << offset);
}
static int nct5104d_gpio_direction_out(struct gpio_chip *chip,
unsigned offset, int value)
{
int err;
struct nct5104d_gpio_bank *bank =
container_of(chip, struct nct5104d_gpio_bank, chip);
struct nct5104d_sio *sio = bank->data->sio;
u8 dir, data_out;
err = superio_enter(sio->addr);
if (err)
return err;
superio_select(sio->addr, SIO_LD_GPIO);
data_out = superio_inb(sio->addr, gpio_data(bank->regbase));
if (value)
data_out |= (1 << offset);
else
data_out &= ~(1 << offset);
superio_outb(sio->addr, gpio_data(bank->regbase), data_out);
dir = superio_inb(sio->addr, gpio_dir(bank->regbase));
dir &= ~(1 << offset);
superio_outb(sio->addr, gpio_dir(bank->regbase), dir);
superio_exit(sio->addr);
return 0;
}
static void nct5104d_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
{
int err;
struct nct5104d_gpio_bank *bank =
container_of(chip, struct nct5104d_gpio_bank, chip);
struct nct5104d_sio *sio = bank->data->sio;
u8 data_out;
err = superio_enter(sio->addr);
if (err)
return;
superio_select(sio->addr, SIO_LD_GPIO);
data_out = superio_inb(sio->addr, gpio_data(bank->regbase));
if (value)
data_out |= (1 << offset);
else
data_out &= ~(1 << offset);
superio_outb(sio->addr, gpio_data(bank->regbase), data_out);
superio_exit(sio->addr);
}
/*
* Platform device and driver.
*/
static int nct5104d_gpio_probe(struct platform_device *pdev)
{
int err;
int i;
struct nct5104d_sio *sio = pdev->dev.platform_data;
struct nct5104d_gpio_data *data;
data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
switch (sio->type) {
case nct5104d:
data->nr_bank = ARRAY_SIZE(nct5104d_gpio_bank);
data->bank = nct5104d_gpio_bank;
break;
default:
return -ENODEV;
}
data->sio = sio;
platform_set_drvdata(pdev, data);
/* For each GPIO bank, register a GPIO chip. */
for (i = 0; i < data->nr_bank; i++) {
struct nct5104d_gpio_bank *bank = &data->bank[i];
bank->chip.dev = &pdev->dev;
bank->data = data;
err = gpiochip_add(&bank->chip);
if (err) {
dev_err(&pdev->dev,
"Failed to register gpiochip %d: %d\n",
i, err);
goto err_gpiochip;
}
}
return 0;
err_gpiochip:
for (i = i - 1; i >= 0; i--) {
struct nct5104d_gpio_bank *bank = &data->bank[i];
int tmp;
//tmp = gpiochip_remove(&bank->chip);
gpiochip_remove(&bank->chip);
tmp = 0;
if (tmp < 0)
dev_err(&pdev->dev,
"Failed to remove gpiochip %d: %d\n",
i, tmp);
}
return err;
}
static int nct5104d_gpio_remove(struct platform_device *pdev)
{
int err;
int i;
struct nct5104d_gpio_data *data = platform_get_drvdata(pdev);
for (i = 0; i < data->nr_bank; i++) {
struct nct5104d_gpio_bank *bank = &data->bank[i];
//err = gpiochip_remove(&bank->chip);
gpiochip_remove(&bank->chip);
err = 0;
if (err) {
dev_err(&pdev->dev,
"Failed to remove GPIO gpiochip %d: %d\n",
i, err);
return err;
}
}
return 0;
}
static int __init nct5104d_find(int addr, struct nct5104d_sio *sio)
{
int err;
u16 devid;
u8 gpio_cfg;
err = superio_enter(addr);
if (err)
return err;
err = -ENODEV;
devid = superio_inw(addr, SIO_CHIPID);
switch (devid) {
case SIO_NCT5104D_ID:
case SIO_PCENGINES_APU_NCT5104D_ID:
sio->type = nct5104d;
/* enable GPIO0 and GPIO1 */
superio_select(addr, SIO_LD_GPIO);
gpio_cfg = superio_inb(addr, SIO_GPIO_ENABLE);
gpio_cfg |= 0x03;
superio_outb(addr, SIO_GPIO_ENABLE, gpio_cfg);
break;
default:
pr_info(DRVNAME ": Unsupported device 0x%04x\n", devid);
goto err;
}
sio->addr = addr;
err = 0;
pr_info(DRVNAME ": Found %s at %#x chip id 0x%04x\n",
nct5104d_names[sio->type],
(unsigned int) addr,
(int) superio_inw(addr, SIO_CHIPID));
superio_select(sio->addr, SIO_LD_GPIO_MODE);
superio_outb(sio->addr, SIO_GPIO1_MODE, 0x0);
superio_outb(sio->addr, SIO_GPIO2_MODE, 0x0);
err:
superio_exit(addr);
return err;
}
static struct platform_device *nct5104d_gpio_pdev;
static int __init
nct5104d_gpio_device_add(const struct nct5104d_sio *sio)
{
int err;
nct5104d_gpio_pdev = platform_device_alloc(DRVNAME, -1);
if (!nct5104d_gpio_pdev)
pr_err(DRVNAME ": Error platform_device_alloc\n");
if (!nct5104d_gpio_pdev)
return -ENOMEM;
err = platform_device_add_data(nct5104d_gpio_pdev,
sio, sizeof(*sio));
if (err) {
pr_err(DRVNAME "Platform data allocation failed\n");
goto err;
}
err = platform_device_add(nct5104d_gpio_pdev);
if (err) {
pr_err(DRVNAME "Device addition failed\n");
goto err;
}
pr_info(DRVNAME ": Device added\n");
return 0;
err:
platform_device_put(nct5104d_gpio_pdev);
return err;
}
/*
*/
static struct platform_driver nct5104d_gpio_driver = {
.driver = {
.owner = THIS_MODULE,
.name = DRVNAME,
},
.probe = nct5104d_gpio_probe,
.remove = nct5104d_gpio_remove,
};
static int __init nct5104d_gpio_init(void)
{
int err;
struct nct5104d_sio sio;
if (nct5104d_find(0x2e, &sio) &&
nct5104d_find(0x4e, &sio))
return -ENODEV;
err = platform_driver_register(&nct5104d_gpio_driver);
if (!err) {
pr_info(DRVNAME ": platform_driver_register\n");
err = nct5104d_gpio_device_add(&sio);
if (err)
platform_driver_unregister(&nct5104d_gpio_driver);
}
return err;
}
subsys_initcall(nct5104d_gpio_init);
static void __exit nct5104d_gpio_exit(void)
{
platform_device_unregister(nct5104d_gpio_pdev);
platform_driver_unregister(&nct5104d_gpio_driver);
}
module_exit(nct5104d_gpio_exit);
MODULE_DESCRIPTION("GPIO driver for Super-I/O chips NCT5104D");
MODULE_AUTHOR("Tasanakorn Phaipool <tasanakorn@gmail.com>");
MODULE_LICENSE("GPL");