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linux/drivers/gpio/gpio-viperboard.c
Axel Lin cfb10898ef gpio: Don't override the error code in probe error handling 
Otherwise, we return 0 in probe error paths when gpiochip_remove() returns 0.
Also show error message if gpiochip_remove() fails.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Cc: Tomoya MORINAGA <tomoya.rohm@gmail.com>
Cc: Denis Turischev <denis@compulab.co.il>
Cc: Lars Poeschel <poeschel@lemonage.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-05-20 20:27:30 +02:00

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/*
* Nano River Technologies viperboard GPIO lib driver
*
* (C) 2012 by Lemonage GmbH
* Author: Lars Poeschel <poeschel@lemonage.de>
* All rights reserved.
*
* 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/kernel.h>
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/mutex.h>
#include <linux/platform_device.h>
#include <linux/usb.h>
#include <linux/gpio.h>
#include <linux/mfd/viperboard.h>
#define VPRBRD_GPIOA_CLK_1MHZ 0
#define VPRBRD_GPIOA_CLK_100KHZ 1
#define VPRBRD_GPIOA_CLK_10KHZ 2
#define VPRBRD_GPIOA_CLK_1KHZ 3
#define VPRBRD_GPIOA_CLK_100HZ 4
#define VPRBRD_GPIOA_CLK_10HZ 5
#define VPRBRD_GPIOA_FREQ_DEFAULT 1000
#define VPRBRD_GPIOA_CMD_CONT 0x00
#define VPRBRD_GPIOA_CMD_PULSE 0x01
#define VPRBRD_GPIOA_CMD_PWM 0x02
#define VPRBRD_GPIOA_CMD_SETOUT 0x03
#define VPRBRD_GPIOA_CMD_SETIN 0x04
#define VPRBRD_GPIOA_CMD_SETINT 0x05
#define VPRBRD_GPIOA_CMD_GETIN 0x06
#define VPRBRD_GPIOB_CMD_SETDIR 0x00
#define VPRBRD_GPIOB_CMD_SETVAL 0x01
struct vprbrd_gpioa_msg {
u8 cmd;
u8 clk;
u8 offset;
u8 t1;
u8 t2;
u8 invert;
u8 pwmlevel;
u8 outval;
u8 risefall;
u8 answer;
u8 __fill;
} __packed;
struct vprbrd_gpiob_msg {
u8 cmd;
u16 val;
u16 mask;
} __packed;
struct vprbrd_gpio {
struct gpio_chip gpioa; /* gpio a related things */
u32 gpioa_out;
u32 gpioa_val;
struct gpio_chip gpiob; /* gpio b related things */
u32 gpiob_out;
u32 gpiob_val;
struct vprbrd *vb;
};
/* gpioa sampling clock module parameter */
static unsigned char gpioa_clk;
static unsigned int gpioa_freq = VPRBRD_GPIOA_FREQ_DEFAULT;
module_param(gpioa_freq, uint, 0);
MODULE_PARM_DESC(gpioa_freq,
"gpio-a sampling freq in Hz (default is 1000Hz) valid values: 10, 100, 1000, 10000, 100000, 1000000");
/* ----- begin of gipo a chip -------------------------------------------- */
static int vprbrd_gpioa_get(struct gpio_chip *chip,
unsigned offset)
{
int ret, answer, error = 0;
struct vprbrd_gpio *gpio =
container_of(chip, struct vprbrd_gpio, gpioa);
struct vprbrd *vb = gpio->vb;
struct vprbrd_gpioa_msg *gamsg = (struct vprbrd_gpioa_msg *)vb->buf;
/* if io is set to output, just return the saved value */
if (gpio->gpioa_out & (1 << offset))
return gpio->gpioa_val & (1 << offset);
mutex_lock(&vb->lock);
gamsg->cmd = VPRBRD_GPIOA_CMD_GETIN;
gamsg->clk = 0x00;
gamsg->offset = offset;
gamsg->t1 = 0x00;
gamsg->t2 = 0x00;
gamsg->invert = 0x00;
gamsg->pwmlevel = 0x00;
gamsg->outval = 0x00;
gamsg->risefall = 0x00;
gamsg->answer = 0x00;
gamsg->__fill = 0x00;
ret = usb_control_msg(vb->usb_dev, usb_sndctrlpipe(vb->usb_dev, 0),
VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_OUT, 0x0000,
0x0000, gamsg, sizeof(struct vprbrd_gpioa_msg),
VPRBRD_USB_TIMEOUT_MS);
if (ret != sizeof(struct vprbrd_gpioa_msg))
error = -EREMOTEIO;
ret = usb_control_msg(vb->usb_dev, usb_rcvctrlpipe(vb->usb_dev, 0),
VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_IN, 0x0000,
0x0000, gamsg, sizeof(struct vprbrd_gpioa_msg),
VPRBRD_USB_TIMEOUT_MS);
answer = gamsg->answer & 0x01;
mutex_unlock(&vb->lock);
if (ret != sizeof(struct vprbrd_gpioa_msg))
error = -EREMOTEIO;
if (error)
return error;
return answer;
}
static void vprbrd_gpioa_set(struct gpio_chip *chip,
unsigned offset, int value)
{
int ret;
struct vprbrd_gpio *gpio =
container_of(chip, struct vprbrd_gpio, gpioa);
struct vprbrd *vb = gpio->vb;
struct vprbrd_gpioa_msg *gamsg = (struct vprbrd_gpioa_msg *)vb->buf;
if (gpio->gpioa_out & (1 << offset)) {
if (value)
gpio->gpioa_val |= (1 << offset);
else
gpio->gpioa_val &= ~(1 << offset);
mutex_lock(&vb->lock);
gamsg->cmd = VPRBRD_GPIOA_CMD_SETOUT;
gamsg->clk = 0x00;
gamsg->offset = offset;
gamsg->t1 = 0x00;
gamsg->t2 = 0x00;
gamsg->invert = 0x00;
gamsg->pwmlevel = 0x00;
gamsg->outval = value;
gamsg->risefall = 0x00;
gamsg->answer = 0x00;
gamsg->__fill = 0x00;
ret = usb_control_msg(vb->usb_dev,
usb_sndctrlpipe(vb->usb_dev, 0),
VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_OUT,
0x0000, 0x0000, gamsg,
sizeof(struct vprbrd_gpioa_msg), VPRBRD_USB_TIMEOUT_MS);
mutex_unlock(&vb->lock);
if (ret != sizeof(struct vprbrd_gpioa_msg))
dev_err(chip->dev, "usb error setting pin value\n");
}
}
static int vprbrd_gpioa_direction_input(struct gpio_chip *chip,
unsigned offset)
{
int ret;
struct vprbrd_gpio *gpio =
container_of(chip, struct vprbrd_gpio, gpioa);
struct vprbrd *vb = gpio->vb;
struct vprbrd_gpioa_msg *gamsg = (struct vprbrd_gpioa_msg *)vb->buf;
gpio->gpioa_out &= ~(1 << offset);
mutex_lock(&vb->lock);
gamsg->cmd = VPRBRD_GPIOA_CMD_SETIN;
gamsg->clk = gpioa_clk;
gamsg->offset = offset;
gamsg->t1 = 0x00;
gamsg->t2 = 0x00;
gamsg->invert = 0x00;
gamsg->pwmlevel = 0x00;
gamsg->outval = 0x00;
gamsg->risefall = 0x00;
gamsg->answer = 0x00;
gamsg->__fill = 0x00;
ret = usb_control_msg(vb->usb_dev, usb_sndctrlpipe(vb->usb_dev, 0),
VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_OUT, 0x0000,
0x0000, gamsg, sizeof(struct vprbrd_gpioa_msg),
VPRBRD_USB_TIMEOUT_MS);
mutex_unlock(&vb->lock);
if (ret != sizeof(struct vprbrd_gpioa_msg))
return -EREMOTEIO;
return 0;
}
static int vprbrd_gpioa_direction_output(struct gpio_chip *chip,
unsigned offset, int value)
{
int ret;
struct vprbrd_gpio *gpio =
container_of(chip, struct vprbrd_gpio, gpioa);
struct vprbrd *vb = gpio->vb;
struct vprbrd_gpioa_msg *gamsg = (struct vprbrd_gpioa_msg *)vb->buf;
gpio->gpioa_out |= (1 << offset);
if (value)
gpio->gpioa_val |= (1 << offset);
else
gpio->gpioa_val &= ~(1 << offset);
mutex_lock(&vb->lock);
gamsg->cmd = VPRBRD_GPIOA_CMD_SETOUT;
gamsg->clk = 0x00;
gamsg->offset = offset;
gamsg->t1 = 0x00;
gamsg->t2 = 0x00;
gamsg->invert = 0x00;
gamsg->pwmlevel = 0x00;
gamsg->outval = value;
gamsg->risefall = 0x00;
gamsg->answer = 0x00;
gamsg->__fill = 0x00;
ret = usb_control_msg(vb->usb_dev, usb_sndctrlpipe(vb->usb_dev, 0),
VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_OUT, 0x0000,
0x0000, gamsg, sizeof(struct vprbrd_gpioa_msg),
VPRBRD_USB_TIMEOUT_MS);
mutex_unlock(&vb->lock);
if (ret != sizeof(struct vprbrd_gpioa_msg))
return -EREMOTEIO;
return 0;
}
/* ----- end of gpio a chip ---------------------------------------------- */
/* ----- begin of gipo b chip -------------------------------------------- */
static int vprbrd_gpiob_setdir(struct vprbrd *vb, unsigned offset,
unsigned dir)
{
struct vprbrd_gpiob_msg *gbmsg = (struct vprbrd_gpiob_msg *)vb->buf;
int ret;
gbmsg->cmd = VPRBRD_GPIOB_CMD_SETDIR;
gbmsg->val = cpu_to_be16(dir << offset);
gbmsg->mask = cpu_to_be16(0x0001 << offset);
ret = usb_control_msg(vb->usb_dev, usb_sndctrlpipe(vb->usb_dev, 0),
VPRBRD_USB_REQUEST_GPIOB, VPRBRD_USB_TYPE_OUT, 0x0000,
0x0000, gbmsg, sizeof(struct vprbrd_gpiob_msg),
VPRBRD_USB_TIMEOUT_MS);
if (ret != sizeof(struct vprbrd_gpiob_msg))
return -EREMOTEIO;
return 0;
}
static int vprbrd_gpiob_get(struct gpio_chip *chip,
unsigned offset)
{
int ret;
u16 val;
struct vprbrd_gpio *gpio =
container_of(chip, struct vprbrd_gpio, gpiob);
struct vprbrd *vb = gpio->vb;
struct vprbrd_gpiob_msg *gbmsg = (struct vprbrd_gpiob_msg *)vb->buf;
/* if io is set to output, just return the saved value */
if (gpio->gpiob_out & (1 << offset))
return gpio->gpiob_val & (1 << offset);
mutex_lock(&vb->lock);
ret = usb_control_msg(vb->usb_dev, usb_rcvctrlpipe(vb->usb_dev, 0),
VPRBRD_USB_REQUEST_GPIOB, VPRBRD_USB_TYPE_IN, 0x0000,
0x0000, gbmsg, sizeof(struct vprbrd_gpiob_msg),
VPRBRD_USB_TIMEOUT_MS);
val = gbmsg->val;
mutex_unlock(&vb->lock);
if (ret != sizeof(struct vprbrd_gpiob_msg))
return ret;
/* cache the read values */
gpio->gpiob_val = be16_to_cpu(val);
return (gpio->gpiob_val >> offset) & 0x1;
}
static void vprbrd_gpiob_set(struct gpio_chip *chip,
unsigned offset, int value)
{
int ret;
struct vprbrd_gpio *gpio =
container_of(chip, struct vprbrd_gpio, gpiob);
struct vprbrd *vb = gpio->vb;
struct vprbrd_gpiob_msg *gbmsg = (struct vprbrd_gpiob_msg *)vb->buf;
if (gpio->gpiob_out & (1 << offset)) {
if (value)
gpio->gpiob_val |= (1 << offset);
else
gpio->gpiob_val &= ~(1 << offset);
mutex_lock(&vb->lock);
gbmsg->cmd = VPRBRD_GPIOB_CMD_SETVAL;
gbmsg->val = cpu_to_be16(value << offset);
gbmsg->mask = cpu_to_be16(0x0001 << offset);
ret = usb_control_msg(vb->usb_dev,
usb_sndctrlpipe(vb->usb_dev, 0),
VPRBRD_USB_REQUEST_GPIOB, VPRBRD_USB_TYPE_OUT,
0x0000, 0x0000, gbmsg,
sizeof(struct vprbrd_gpiob_msg), VPRBRD_USB_TIMEOUT_MS);
mutex_unlock(&vb->lock);
if (ret != sizeof(struct vprbrd_gpiob_msg))
dev_err(chip->dev, "usb error setting pin value\n");
}
}
static int vprbrd_gpiob_direction_input(struct gpio_chip *chip,
unsigned offset)
{
int ret;
struct vprbrd_gpio *gpio =
container_of(chip, struct vprbrd_gpio, gpiob);
struct vprbrd *vb = gpio->vb;
gpio->gpiob_out &= ~(1 << offset);
mutex_lock(&vb->lock);
ret = vprbrd_gpiob_setdir(vb, offset, 0);
mutex_unlock(&vb->lock);
if (ret)
dev_err(chip->dev, "usb error setting pin to input\n");
return ret;
}
static int vprbrd_gpiob_direction_output(struct gpio_chip *chip,
unsigned offset, int value)
{
int ret;
struct vprbrd_gpio *gpio =
container_of(chip, struct vprbrd_gpio, gpiob);
struct vprbrd *vb = gpio->vb;
gpio->gpiob_out |= (1 << offset);
mutex_lock(&vb->lock);
ret = vprbrd_gpiob_setdir(vb, offset, 1);
if (ret)
dev_err(chip->dev, "usb error setting pin to output\n");
mutex_unlock(&vb->lock);
vprbrd_gpiob_set(chip, offset, value);
return ret;
}
/* ----- end of gpio b chip ---------------------------------------------- */
static int vprbrd_gpio_probe(struct platform_device *pdev)
{
struct vprbrd *vb = dev_get_drvdata(pdev->dev.parent);
struct vprbrd_gpio *vb_gpio;
int ret;
vb_gpio = devm_kzalloc(&pdev->dev, sizeof(*vb_gpio), GFP_KERNEL);
if (vb_gpio == NULL)
return -ENOMEM;
vb_gpio->vb = vb;
/* registering gpio a */
vb_gpio->gpioa.label = "viperboard gpio a";
vb_gpio->gpioa.dev = &pdev->dev;
vb_gpio->gpioa.owner = THIS_MODULE;
vb_gpio->gpioa.base = -1;
vb_gpio->gpioa.ngpio = 16;
vb_gpio->gpioa.can_sleep = 1;
vb_gpio->gpioa.set = vprbrd_gpioa_set;
vb_gpio->gpioa.get = vprbrd_gpioa_get;
vb_gpio->gpioa.direction_input = vprbrd_gpioa_direction_input;
vb_gpio->gpioa.direction_output = vprbrd_gpioa_direction_output;
ret = gpiochip_add(&vb_gpio->gpioa);
if (ret < 0) {
dev_err(vb_gpio->gpioa.dev, "could not add gpio a");
goto err_gpioa;
}
/* registering gpio b */
vb_gpio->gpiob.label = "viperboard gpio b";
vb_gpio->gpiob.dev = &pdev->dev;
vb_gpio->gpiob.owner = THIS_MODULE;
vb_gpio->gpiob.base = -1;
vb_gpio->gpiob.ngpio = 16;
vb_gpio->gpiob.can_sleep = 1;
vb_gpio->gpiob.set = vprbrd_gpiob_set;
vb_gpio->gpiob.get = vprbrd_gpiob_get;
vb_gpio->gpiob.direction_input = vprbrd_gpiob_direction_input;
vb_gpio->gpiob.direction_output = vprbrd_gpiob_direction_output;
ret = gpiochip_add(&vb_gpio->gpiob);
if (ret < 0) {
dev_err(vb_gpio->gpiob.dev, "could not add gpio b");
goto err_gpiob;
}
platform_set_drvdata(pdev, vb_gpio);
return ret;
err_gpiob:
if (gpiochip_remove(&vb_gpio->gpioa))
dev_err(&pdev->dev, "%s gpiochip_remove failed\n", __func__);
err_gpioa:
return ret;
}
static int vprbrd_gpio_remove(struct platform_device *pdev)
{
struct vprbrd_gpio *vb_gpio = platform_get_drvdata(pdev);
int ret;
ret = gpiochip_remove(&vb_gpio->gpiob);
if (ret == 0)
ret = gpiochip_remove(&vb_gpio->gpioa);
return ret;
}
static struct platform_driver vprbrd_gpio_driver = {
.driver.name = "viperboard-gpio",
.driver.owner = THIS_MODULE,
.probe = vprbrd_gpio_probe,
.remove = vprbrd_gpio_remove,
};
static int __init vprbrd_gpio_init(void)
{
switch (gpioa_freq) {
case 1000000:
gpioa_clk = VPRBRD_GPIOA_CLK_1MHZ;
break;
case 100000:
gpioa_clk = VPRBRD_GPIOA_CLK_100KHZ;
break;
case 10000:
gpioa_clk = VPRBRD_GPIOA_CLK_10KHZ;
break;
case 1000:
gpioa_clk = VPRBRD_GPIOA_CLK_1KHZ;
break;
case 100:
gpioa_clk = VPRBRD_GPIOA_CLK_100HZ;
break;
case 10:
gpioa_clk = VPRBRD_GPIOA_CLK_10HZ;
break;
default:
pr_warn("invalid gpioa_freq (%d)\n", gpioa_freq);
gpioa_clk = VPRBRD_GPIOA_CLK_1KHZ;
}
return platform_driver_register(&vprbrd_gpio_driver);
}
subsys_initcall(vprbrd_gpio_init);
static void __exit vprbrd_gpio_exit(void)
{
platform_driver_unregister(&vprbrd_gpio_driver);
}
module_exit(vprbrd_gpio_exit);
MODULE_AUTHOR("Lars Poeschel <poeschel@lemonage.de>");
MODULE_DESCRIPTION("GPIO driver for Nano River Techs Viperboard");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:viperboard-gpio");
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