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Merge pull request #67 from MK16kawai/main

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[i2c5@gpio] supports dynamic rate modification
This commit is contained in:
Neucrack
2024-12-10 15:07:06 +08:00
committed by GitHub
parent fae0437895 b9189b85b1
commit ae8d34b5c9
1 changed files with 90 additions and 0 deletions
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90
linux_5.10/drivers/i2c/busses/i2c-gpio.c
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@@ -18,6 +18,20 @@
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/sysfs.h>
#include <linux/kobject.h>
#include <linux/err.h>
#define DEBUG_LOG_TAG "[i2c gpio]"
#define DEBUG_LOG(fmt, ...) printk(KERN_DEBUG DEBUG_LOG_TAG " " fmt, ##__VA_ARGS__)
static int delay_us = -1;
volatile int udelay_value = 0;
struct kobject *udelay_v;
struct i2c_algo_bit_data *udelay_data = NULL;
struct i2c_gpio_private_data {
struct gpio_desc *sda;
struct gpio_desc *scl;
@@ -32,6 +46,49 @@ struct i2c_gpio_private_data {
#endif
};
static void show_freq(void)
{
switch(udelay_data->udelay) {
case 0:
DEBUG_LOG("Freq max ~ 750KHz for MaixCAM");
break;
case 1:
DEBUG_LOG("Freq 500KHz ~ 308KHz for MaixCAM");
break;
case 2:
DEBUG_LOG("Freq 250KHz");
break;
case 5:
DEBUG_LOG("Freq 100KHz");
break;
default:
DEBUG_LOG("Freq - Unknown");
break;
}
}
static ssize_t __udelay_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
// DEBUG_LOG("Read udelay value: %d\n", udelay_value);
show_freq();
udelay_value = udelay_data->udelay;
return sprintf(buf, "%d", udelay_value);
}
static ssize_t __udelay_store(struct kobject *kobj,
struct kobj_attribute *attr,const char *buf, size_t count)
{
// int old_value = udelay_value;
sscanf(buf,"%d",&udelay_value);
udelay_data->udelay = udelay_value;
// DEBUG_LOG("Write udelay value: %d --> %d\n", old_value, udelay_value);
// show_freq();
return count;
}
struct kobj_attribute sysfs_test_attr = __ATTR(udelay_v, 0664, __udelay_show, __udelay_store);
/*
* Toggle SDA by changing the output value of the pin. This is only
* valid for pins configured as open drain (i.e. setting the value
@@ -364,6 +421,7 @@ static int i2c_gpio_probe(struct platform_device *pdev)
struct device_node *np = dev->of_node;
enum gpiod_flags gflags;
int ret;
struct device *curr_dev;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
@@ -420,6 +478,9 @@ static int i2c_gpio_probe(struct platform_device *pdev)
bit_data->getscl = i2c_gpio_getscl;
bit_data->getsda = i2c_gpio_getsda;
udelay_data = bit_data;
/* Get udelay from device tree */
if (pdata->udelay)
bit_data->udelay = pdata->udelay;
else if (pdata->scl_is_output_only)
@@ -432,6 +493,17 @@ 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 (delay_us >= 0) {
DEBUG_LOG("Get parameters 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("delay us: %d\n", bit_data->udelay);
show_freq();
bit_data->data = priv;
adap->owner = THIS_MODULE;
@@ -464,6 +536,17 @@ static int i2c_gpio_probe(struct platform_device *pdev)
i2c_gpio_fault_injector_init(pdev);
/* Add udelay kobj */
curr_dev = &pdev->dev;
udelay_v = kobject_create_and_add("udelay_value", &curr_dev->kobj);
if(sysfs_create_file(udelay_v, &sysfs_test_attr.attr)){
DEBUG_LOG("Create sysfs file failed!\n");
kobject_put(udelay_v);
sysfs_remove_file(kernel_kobj, &sysfs_test_attr.attr);
}
udelay_value = udelay_data->udelay;
return 0;
}
@@ -479,6 +562,10 @@ static int i2c_gpio_remove(struct platform_device *pdev)
i2c_del_adapter(adap);
/* Remove udelay kobj */
kobject_put(udelay_v);
sysfs_remove_file(kernel_kobj, &sysfs_test_attr.attr);
return 0;
}
@@ -500,6 +587,9 @@ static struct platform_driver i2c_gpio_driver = {
.remove = i2c_gpio_remove,
};
module_param(delay_us, int, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(delay_us, "An integer parameter for the i2c udelay");
static int __init i2c_gpio_init(void)
{
int ret;