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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2023 Loongson Technology Corporation Limited
*/
#include <drm/drm_managed.h>
#include "lsdc_drv.h"
#include "lsdc_output.h"
/*
* __lsdc_gpio_i2c_set - set the state of a gpio pin indicated by mask
* @mask: gpio pin mask
* @state: "0" for low, "1" for high
*/
static void __lsdc_gpio_i2c_set(struct lsdc_i2c * const li2c, int mask, int state)
{
struct lsdc_device *ldev = to_lsdc(li2c->ddev);
unsigned long flags;
u8 val;
spin_lock_irqsave(&ldev->reglock, flags);
if (state) {
/*
* Setting this pin as input directly, write 1 for input.
* The external pull-up resistor will pull the level up
*/
val = readb(li2c->dir_reg);
val |= mask;
writeb(val, li2c->dir_reg);
} else {
/* First set this pin as output, write 0 for output */
val = readb(li2c->dir_reg);
val &= ~mask;
writeb(val, li2c->dir_reg);
/* Then, make this pin output 0 */
val = readb(li2c->dat_reg);
val &= ~mask;
writeb(val, li2c->dat_reg);
}
spin_unlock_irqrestore(&ldev->reglock, flags);
}
/*
* __lsdc_gpio_i2c_get - read value back from the gpio pin indicated by mask
* @mask: gpio pin mask
* return "0" for low, "1" for high
*/
static int __lsdc_gpio_i2c_get(struct lsdc_i2c * const li2c, int mask)
{
struct lsdc_device *ldev = to_lsdc(li2c->ddev);
unsigned long flags;
u8 val;
spin_lock_irqsave(&ldev->reglock, flags);
/* First set this pin as input */
val = readb(li2c->dir_reg);
val |= mask;
writeb(val, li2c->dir_reg);
/* Then get level state from this pin */
val = readb(li2c->dat_reg);
spin_unlock_irqrestore(&ldev->reglock, flags);
return (val & mask) ? 1 : 0;
}
static void lsdc_gpio_i2c_set_sda(void *i2c, int state)
{
struct lsdc_i2c * const li2c = (struct lsdc_i2c *)i2c;
/* set state on the li2c->sda pin */
return __lsdc_gpio_i2c_set(li2c, li2c->sda, state);
}
static void lsdc_gpio_i2c_set_scl(void *i2c, int state)
{
struct lsdc_i2c * const li2c = (struct lsdc_i2c *)i2c;
/* set state on the li2c->scl pin */
return __lsdc_gpio_i2c_set(li2c, li2c->scl, state);
}
static int lsdc_gpio_i2c_get_sda(void *i2c)
{
struct lsdc_i2c * const li2c = (struct lsdc_i2c *)i2c;
/* read value from the li2c->sda pin */
return __lsdc_gpio_i2c_get(li2c, li2c->sda);
}
static int lsdc_gpio_i2c_get_scl(void *i2c)
{
struct lsdc_i2c * const li2c = (struct lsdc_i2c *)i2c;
/* read the value from the li2c->scl pin */
return __lsdc_gpio_i2c_get(li2c, li2c->scl);
}
static void lsdc_destroy_i2c(struct drm_device *ddev, void *data)
{
struct lsdc_i2c *li2c = (struct lsdc_i2c *)data;
if (li2c) {
i2c_del_adapter(&li2c->adapter);
kfree(li2c);
}
}
/*
* The DC in ls7a1000/ls7a2000/ls2k2000 has builtin gpio hardware
*
* @reg_base: gpio reg base
* @index: output channel index, 0 for PIPE0, 1 for PIPE1
*/
int lsdc_create_i2c_chan(struct drm_device *ddev,
struct lsdc_display_pipe *dispipe,
unsigned int index)
{
struct lsdc_device *ldev = to_lsdc(ddev);
struct i2c_adapter *adapter;
struct lsdc_i2c *li2c;
int ret;
li2c = kzalloc(sizeof(*li2c), GFP_KERNEL);
if (!li2c)
return -ENOMEM;
dispipe->li2c = li2c;
if (index == 0) {
li2c->sda = 0x01; /* pin 0 */
li2c->scl = 0x02; /* pin 1 */
} else if (index == 1) {
li2c->sda = 0x04; /* pin 2 */
li2c->scl = 0x08; /* pin 3 */
} else {
return -ENOENT;
}
li2c->ddev = ddev;
li2c->dir_reg = ldev->reg_base + LS7A_DC_GPIO_DIR_REG;
li2c->dat_reg = ldev->reg_base + LS7A_DC_GPIO_DAT_REG;
li2c->bit.setsda = lsdc_gpio_i2c_set_sda;
li2c->bit.setscl = lsdc_gpio_i2c_set_scl;
li2c->bit.getsda = lsdc_gpio_i2c_get_sda;
li2c->bit.getscl = lsdc_gpio_i2c_get_scl;
li2c->bit.udelay = 5;
li2c->bit.timeout = usecs_to_jiffies(2200);
li2c->bit.data = li2c;
adapter = &li2c->adapter;
adapter->algo_data = &li2c->bit;
adapter->owner = THIS_MODULE;
adapter->dev.parent = ddev->dev;
adapter->nr = -1;
snprintf(adapter->name, sizeof(adapter->name), "lsdc-i2c%u", index);
i2c_set_adapdata(adapter, li2c);
ret = i2c_bit_add_bus(adapter);
if (ret) {
kfree(li2c);
return ret;
}
ret = drmm_add_action_or_reset(ddev, lsdc_destroy_i2c, li2c);
if (ret)
return ret;
drm_info(ddev, "%s(sda pin mask=%u, scl pin mask=%u) created\n",
adapter->name, li2c->sda, li2c->scl);
return 0;
}
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