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Merge pull request #71 from MK16kawai/main

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[i2c@gpio5] Support for changing sda and scl at insmod time.
This commit is contained in:
Neucrack
2024-12-20 19:04:06 +08:00
committed by GitHub
parent 1fcc2fd409 370d332f61
commit b8e61612e5
1 changed files with 85 additions and 18 deletions
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103
linux_5.10/drivers/i2c/busses/i2c-gpio.c
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@@ -7,6 +7,7 @@
#include <linux/completion.h>
#include <linux/debugfs.h>
#include <linux/delay.h>
#include <linux/gpio.h>
#include <linux/gpio/consumer.h>
#include <linux/i2c-algo-bit.h>
#include <linux/i2c.h>
@@ -32,6 +33,11 @@ volatile int udelay_value = 0;
struct kobject *udelay_v;
struct i2c_algo_bit_data *udelay_data = NULL;
static int sda = -1;
static int scl = -1;
static bool insmod_gpio = false;
struct i2c_gpio_private_data {
struct gpio_desc *sda;
struct gpio_desc *scl;
@@ -419,7 +425,8 @@ static int i2c_gpio_probe(struct platform_device *pdev)
struct i2c_adapter *adap;
struct device *dev = &pdev->dev;
struct device_node *np = dev->of_node;
enum gpiod_flags gflags;
enum gpiod_flags gflags_sda, gflags_scl;
unsigned long gf_sda, gf_scl;
int ret;
struct device *curr_dev;
@@ -442,6 +449,9 @@ static int i2c_gpio_probe(struct platform_device *pdev)
memcpy(pdata, dev_get_platdata(dev), sizeof(*pdata));
}
/* 508 SCL
509 SDA */
/*
* First get the GPIO pins; if it fails, we'll defer the probe.
* If the SCL/SDA lines are marked "open drain" by platform data or
@@ -450,21 +460,67 @@ static int i2c_gpio_probe(struct platform_device *pdev)
* handle them as we handle any other output. Else we enforce open
* drain as this is required for an I2C bus.
*/
if (pdata->sda_is_open_drain)
gflags = GPIOD_OUT_HIGH;
else
gflags = GPIOD_OUT_HIGH_OPEN_DRAIN;
priv->sda = i2c_gpio_get_desc(dev, "sda", 0, gflags);
if (IS_ERR(priv->sda))
return PTR_ERR(priv->sda);
if (sda >= 0 && scl >= 0) {
DEBUG_LOG("used sda %d and scl %d without device tree\n", sda, scl);
if (pdata->scl_is_open_drain)
gflags = GPIOD_OUT_HIGH;
else
gflags = GPIOD_OUT_HIGH_OPEN_DRAIN;
priv->scl = i2c_gpio_get_desc(dev, "scl", 1, gflags);
if (IS_ERR(priv->scl))
return PTR_ERR(priv->scl);
if (pdata->sda_is_open_drain) {
gf_sda = GPIOF_OUT_INIT_HIGH;
} else
gf_sda = GPIOF_OUT_INIT_HIGH | GPIOF_OPEN_DRAIN;
if (pdata->scl_is_open_drain)
gf_scl = GPIOF_OUT_INIT_HIGH;
else
gf_scl = GPIOF_OUT_INIT_HIGH | GPIOF_OPEN_DRAIN;
/* request sda */
ret = gpio_request_one(sda, gf_sda, "sda");
if (ret < 0) {
DEBUG_LOG("request sda failed!\n");
return -1;
}
priv->sda = gpio_to_desc(sda);
if (IS_ERR(priv->sda))
return PTR_ERR(priv->sda);
DEBUG_LOG("request sda succ!\n");
/* request scl */
ret = gpio_request_one(scl, gf_scl, "scl");
if (ret < 0) {
DEBUG_LOG("request scl failed!\n");
DEBUG_LOG("release sda\n");
gpio_free(sda);
return -1;
}
priv->scl = gpio_to_desc(scl);
if (IS_ERR(priv->scl))
return PTR_ERR(priv->scl);
DEBUG_LOG("request scl succ!\n");
insmod_gpio = true;
} else {
if (pdata->sda_is_open_drain)
gflags_sda = GPIOD_OUT_HIGH;
else
gflags_sda = GPIOD_OUT_HIGH_OPEN_DRAIN;
if (pdata->scl_is_open_drain)
gflags_scl = GPIOD_OUT_HIGH;
else
gflags_scl = GPIOD_OUT_HIGH_OPEN_DRAIN;
DEBUG_LOG("used sda and scl with device tree\n");
priv->sda = i2c_gpio_get_desc(dev, "sda", 0, gflags_sda);
if (IS_ERR(priv->sda))
return PTR_ERR(priv->sda);
priv->scl = i2c_gpio_get_desc(dev, "scl", 1, gflags_scl);
if (IS_ERR(priv->scl))
return PTR_ERR(priv->scl);
insmod_gpio = false;
}
if (gpiod_cansleep(priv->sda) || gpiod_cansleep(priv->scl))
dev_warn(dev, "Slow GPIO pins might wreak havoc into I2C/SMBus bus timing");
@@ -493,12 +549,12 @@ static int i2c_gpio_probe(struct platform_device *pdev)
else
bit_data->timeout = HZ / 10; /* 100 ms */
/* If `insmod ko udelay_value=x` (x>=0) */
/* If `insmod ko delay_us=x` (x>=0) */
if (delay_us >= 0) {
DEBUG_LOG("Get parameters from insmod: %d\n", delay_us);
DEBUG_LOG("Get delay_us from insmod: %d\n", delay_us);
bit_data->udelay = delay_us;
} else {
DEBUG_LOG("Get parameters from device tree: %d\n", bit_data->udelay);
DEBUG_LOG("Get delay_us from device tree: %d\n", bit_data->udelay);
}
DEBUG_LOG("delay us: %d\n", bit_data->udelay);
@@ -555,6 +611,11 @@ static int i2c_gpio_remove(struct platform_device *pdev)
struct i2c_gpio_private_data *priv;
struct i2c_adapter *adap;
if (insmod_gpio) {
gpio_free(scl);
gpio_free(sda);
}
i2c_gpio_fault_injector_exit(pdev);
priv = platform_get_drvdata(pdev);
@@ -590,6 +651,12 @@ static struct platform_driver i2c_gpio_driver = {
module_param(delay_us, int, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(delay_us, "An integer parameter for the i2c udelay");
module_param(sda, int, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(sda, "sda gpio");
module_param(scl, int, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(scl, "scl gpio");
static int __init i2c_gpio_init(void)
{
int ret;