Hi, sunhao.
>
> Add GPIO and I2C driver to detect connector and fetch EDID via DDC.
> ---
> drivers/gpu/drm/loongson/Makefile | 3 +-
> drivers/gpu/drm/loongson/loongson_connector.c | 120 +++++++-
> drivers/gpu/drm/loongson/loongson_drv.c | 16 +-
> drivers/gpu/drm/loongson/loongson_drv.h | 10 +
> drivers/gpu/drm/loongson/loongson_i2c.c | 264 ++++++++++++++++++
> drivers/gpu/drm/loongson/loongson_i2c.h | 40 +++
> 6 files changed, 446 insertions(+), 7 deletions(-)
> create mode 100644 drivers/gpu/drm/loongson/loongson_i2c.c
> create mode 100644 drivers/gpu/drm/loongson/loongson_i2c.h
>
> diff --git a/drivers/gpu/drm/loongson/Makefile b/drivers/gpu/drm/loongson/Makefile
> index 22d063953..773b806e9 100644
> --- a/drivers/gpu/drm/loongson/Makefile
> +++ b/drivers/gpu/drm/loongson/Makefile
> @@ -10,5 +10,6 @@ loongson-y := loongson_drv.o \
> loongson_plane.o \
> loongson_device.o \
> loongson_connector.o \
> - loongson_encoder.o
> + loongson_encoder.o \
> + loongson_i2c.o
> obj-$(CONFIG_DRM_LOONGSON) += loongson.o
> diff --git a/drivers/gpu/drm/loongson/loongson_connector.c b/drivers/gpu/drm/loongson/loongson_connector.c
> index 6b1f0ffa3..e0aea8553 100644
> --- a/drivers/gpu/drm/loongson/loongson_connector.c
> +++ b/drivers/gpu/drm/loongson/loongson_connector.c
> @@ -2,14 +2,117 @@
>
> #include "loongson_drv.h"
>
> +static int loongson_do_probe_ddc_edid(struct i2c_adapter *adapter,
> + unsigned char *buf)
> +{
> + u8 start = 0x0;
> + u32 che_tmp = 0;
> + u32 i;
> +
> + struct i2c_msg msgs[] = { {
> + .addr = DDC_ADDR,
> + .flags = 0,
> + .len = 1,
> + .buf = &start,
> + },
> + {
> + .addr = DDC_ADDR,
> + .flags = I2C_M_RD,
> + .len = EDID_LENGTH * 2,
> + .buf = buf,
> + } };
> +
> + if (i2c_transfer(adapter, msgs, 2) == 2) {
> + if (buf[126] != 0) {
> + buf[126] = 0;
> + che_tmp = 0;
> + for (i = 0; i < 127; i++)
> + che_tmp += buf[i];
> + buf[127] = 256 - (che_tmp) % 256;
> + }
> + if (!drm_edid_block_valid(buf, 0, true, NULL)) {
> + dev_warn_once(&adapter->dev, "Invalid EDID block\n");
> + return false;
> + }
> + } else {
> + dev_warn_once(&adapter->dev, "unable to read EDID block\n");
> + return false;
> + }
> +
> + return true;
> +}
> +
> +static bool get_edid_i2c(struct loongson_connector *lconnector, u8 *edid)
> +{
> + struct loongson_i2c *i2c = lconnector->i2c;
> + bool ret = false;
> +
> + if (i2c != NULL && i2c->adapter != NULL)
> + ret = loongson_do_probe_ddc_edid(i2c->adapter, edid);
> + else
> + DRM_INFO_ONCE("get loongson connector adapter err\n");
> +
> + return ret;
> +
> static int loongson_get_modes(struct drm_connector *connector)
> {
> - int count;
> + struct loongson_connector *lconnector;
> + u8 edid[EDID_LENGTH * 2];
> + u32 size;
> + bool success;
> + u32 ret;
> +
> + lconnector = to_loongson_connector(connector);
> + size = sizeof(u8) * EDID_LENGTH * 2;
> +
> + success = get_edid_i2c(lconnector, edid);
> +
> + if (success) {
> + drm_connector_update_edid_property(connector,
> + (struct edid *)edid);
> + ret = drm_add_edid_modes(connector, (struct edid *)edid);
> + } else
> + ret = drm_add_modes_noedid(connector, 1024, 768);
> +
> + return ret;
> +}
> +
> +static bool is_connected(struct loongson_connector *ls_connector)
> +{
> + unsigned char start = 0x0;
> + struct i2c_adapter *adapter;
> + struct i2c_msg msgs = {
> + .addr = DDC_ADDR,
> + .flags = 0,
> + .len = 1,
> + .buf = &start,
> + };
> +
> + if (!ls_connector->i2c)
> + return false;
>
> - count = drm_add_modes_noedid(connector, 1920, 1080);
> - drm_set_preferred_mode(connector, 1024, 768);
> + adapter = ls_connector->i2c->adapter;
> + if (i2c_transfer(adapter, &msgs, 1) != 1) {
> + DRM_DEBUG_KMS("display-%d not connect\n", ls_connector->id);
> + return false;
> + }
>
> - return count;
> + return true;
> +}
> +
> +static enum drm_connector_status
> +loongson_detect(struct drm_connector *connector, bool force)
> +{
> + struct loongson_connector *lconnector;
> + enum drm_connector_status ret = connector_status_disconnected;
> +
> + lconnector = to_loongson_connector(connector);
> +
> + if (is_connected(lconnector))
> + ret = connector_status_connected;
> +
> + return ret;
> }
>
> static const struct drm_connector_helper_funcs loongson_connector_helper = {
> @@ -17,6 +120,7 @@ static const struct drm_connector_helper_funcs loongson_connector_helper = {
> };
>
> static const struct drm_connector_funcs loongson_connector_funcs = {
> + .detect = loongson_detect,
> .fill_modes = drm_helper_probe_single_connector_modes,
> .destroy = drm_connector_cleanup,
> .reset = drm_atomic_helper_connector_reset,
> @@ -37,11 +141,17 @@ int loongson_connector_init(struct loongson_device *ldev, int index)
>
> lconnector->ldev = ldev;
> lconnector->id = index;
> + lconnector->i2c_id = index + DC_I2C_BASE;
> +
> + lconnector->i2c = loongson_i2c_bus_match(ldev, lconnector->i2c_id);
> + if (!lconnector->i2c)
> + DRM_INFO("connector-%d match i2c-%d err\n", index,
> + lconnector->i2c_id);
>
> ldev->mode_info[index].connector = lconnector;
> connector = &lconnector->base;
> drm_connector_init(ldev->dev, connector, &loongson_connector_funcs,
> - DRM_MODE_CONNECTOR_Unknown);
> + DRM_MODE_CONNECTOR_Unknown);
> drm_connector_helper_add(connector, &loongson_connector_helper);
>
> return 0;
> diff --git a/drivers/gpu/drm/loongson/loongson_drv.c b/drivers/gpu/drm/loongson/loongson_drv.c
> index e405199a3..252be9e25 100644
> --- a/drivers/gpu/drm/loongson/loongson_drv.c
> +++ b/drivers/gpu/drm/loongson/loongson_drv.c
> @@ -11,9 +11,10 @@
>
> /* Interface history:
> * 0.1 - original.
> + * 0.2 - add i2c and connector detect.
> */
> #define DRIVER_MAJOR 0
> -#define DRIVER_MINOR 1
> +#define DRIVER_MINOR 2
>
> static const struct drm_mode_config_funcs loongson_mode_funcs = {
> .fb_create = drm_gem_fb_create,
> @@ -31,6 +32,7 @@ static int loongson_device_init(struct drm_device *dev, uint32_t flags)
> resource_size_t aper_size;
> resource_size_t mmio_base;
> resource_size_t mmio_size;
> + u32 ret;
>
> /* GPU MEM */
> /* We need get 7A-gpu pci device information for ldev->gpu_pdev */
> @@ -72,6 +74,18 @@ static int loongson_device_init(struct drm_device *dev, uint32_t flags)
> if (ldev->io == NULL)
> return -ENOMEM;
>
> + ret = loongson_dc_gpio_init(ldev);
> + if (ret) {
> + DRM_ERROR("Failed to initialize dc gpios\n");
> + return ret;
> + }
> +
> + ret = loongson_i2c_init(ldev);
> + if (ret) {
> + DRM_ERROR("Failed to initialize dc i2c\n");
> + return ret;
> + }
> +
> DRM_INFO("DC mmio base 0x%llx size 0x%llx io 0x%llx\n",
> mmio_base, mmio_size, *(u64 *)ldev->io);
> DRM_INFO("GPU vram start = 0x%x size = 0x%x\n",
> diff --git a/drivers/gpu/drm/loongson/loongson_drv.h b/drivers/gpu/drm/loongson/loongson_drv.h
> index 498d1b082..24a534c3c 100644
> --- a/drivers/gpu/drm/loongson/loongson_drv.h
> +++ b/drivers/gpu/drm/loongson/loongson_drv.h
> @@ -18,6 +18,7 @@
> #include <drm/drm_crtc_helper.h>
> #include <drm/drm_connector.h>
> #include <drm/drm_encoder.h>
> +#include "loongson_i2c.h"
>
> /* General customization:
> */
> @@ -28,6 +29,7 @@
>
> #define to_loongson_crtc(x) container_of(x, struct loongson_crtc, base)
> #define to_loongson_encoder(x) container_of(x, struct loongson_encoder, base)
> +#define to_loongson_connector(x) container_of(x, struct loongson_connector, base)
>
> #define LS7A_CHIPCFG_REG_BASE (0x10010000)
> #define PCI_DEVICE_ID_LOONGSON_DC 0x7a06
> @@ -92,8 +94,10 @@ struct loongson_encoder {
> struct loongson_connector {
> struct drm_connector base;
> struct loongson_device *ldev;
> + struct loongson_i2c *i2c;
> u16 id;
> u32 type;
> + u16 i2c_id;
> };
>
> struct loongson_mode_info {
> @@ -115,6 +119,9 @@ struct loongson_device {
> u32 num_crtc;
> struct loongson_mode_info mode_info[2];
> struct pci_dev *gpu_pdev; /* LS7A gpu device info */
> +
> + struct loongson_i2c i2c_bus[LS_MAX_I2C_BUS];
> + struct gpio_chip chip;
> };
>
> /* crtc */
> @@ -129,6 +136,9 @@ int loongson_encoder_init(struct loongson_device *ldev, int index);
> /* plane */
> int loongson_plane_init(struct loongson_crtc *lcrtc);
>
> +/* i2c */
> +int loongson_dc_gpio_init(struct loongson_device *ldev);
> +
> /* device */
> u32 loongson_gpu_offset(struct drm_plane_state *state);
> u32 ls7a_mm_rreg(struct loongson_device *ldev, u32 offset);
> diff --git a/drivers/gpu/drm/loongson/loongson_i2c.c b/drivers/gpu/drm/loongson/loongson_i2c.c
> new file mode 100644
> index 000000000..b34c9e3c4
> --- /dev/null
> +++ b/drivers/gpu/drm/loongson/loongson_i2c.c
> @@ -0,0 +1,264 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +
> +#include "loongson_i2c.h"
> +#include "loongson_drv.h"
> +#include "linux/gpio.h"
> +#include <linux/gpio/consumer.h>
> +
> +static struct gpio i2c_gpios[4] = {
> + { .gpio = DC_GPIO_0, .flags = GPIOF_OPEN_DRAIN, .label = "i2c-6-sda" },
> + { .gpio = DC_GPIO_1, .flags = GPIOF_OPEN_DRAIN, .label = "i2c-6-scl" },
> + { .gpio = DC_GPIO_2, .flags = GPIOF_OPEN_DRAIN, .label = "i2c-7-sda" },
> + { .gpio = DC_GPIO_3, .flags = GPIOF_OPEN_DRAIN, .label = "i2c-7-scl" },
> +};
> +
> +static inline void __dc_gpio_set_dir(struct loongson_device *ldev, unsigned int pin, int input)
> +{
> + u32 temp;
> +
> + temp = ls_mm_rreg_locked(ldev, LS7A_DC_GPIO_CFG_OFFSET);
> + if (input)
> + temp |= 1UL << pin;
> + else
> + temp &= ~(1UL << pin);
> + ls_mm_wreg_locked(ldev, LS7A_DC_GPIO_CFG_OFFSET, temp);
> +}
> +
> +static void __dc_gpio_set_val(struct loongson_device *ldev, unsigned int pin, int high)
> +{
> + u32 temp;
> +
> + temp = ls_mm_rreg_locked(ldev, LS7A_DC_GPIO_OUT_OFFSET);
> + if (high)
> + temp |= 1UL << pin;
> + else
> + temp &= ~(1UL << pin);
> + ls_mm_wreg_locked(ldev, LS7A_DC_GPIO_OUT_OFFSET, temp);
> +}
> +
> +static int ls_dc_gpio_request(struct gpio_chip *chip, unsigned int pin)
> +{
> + if (pin >= (chip->ngpio + chip->base))
> + return -EINVAL;
> + else
> + return 0;
> +}
> +
> +static int ls_dc_gpio_dir_input(struct gpio_chip *chip, unsigned int pin)
> +{
> + struct loongson_device *ldev;
> +
> + ldev = container_of(chip, struct loongson_device, chip);
> + __dc_gpio_set_dir(ldev, pin, 1);
> +
> + return 0;
> +}
> +
> +static int ls_dc_gpio_dir_output(struct gpio_chip *chip, unsigned int pin, int value)
> +{
> + struct loongson_device *ldev;
> +
> + ldev = container_of(chip, struct loongson_device, chip);
> + __dc_gpio_set_val(ldev, pin, value);
> + __dc_gpio_set_dir(ldev, pin, 0);
> +
> + return 0;
> +}
> +
> +static void ls_dc_gpio_set(struct gpio_chip *chip, unsigned int pin, int value)
> +{
> + struct loongson_device *ldev;
> +
> + ldev = container_of(chip, struct loongson_device, chip);
> + __dc_gpio_set_val(ldev, pin, value);
> +}
> +
> +static int ls_dc_gpio_get(struct gpio_chip *chip, unsigned int pin)
> +{
> + u32 val;
> + struct loongson_device *ldev;
> +
> + ldev = container_of(chip, struct loongson_device, chip);
> + val = ls_mm_rreg_locked(ldev, LS7A_DC_GPIO_IN_OFFSET);
> + return (val >> pin) & 1;
> +}
> +
> +static void loongson_i2c_set_data(void *i2c, int value)
> +{
> + struct loongson_i2c *li2c = i2c;
> + struct gpio_desc *gpiod = gpio_to_desc(i2c_gpios[li2c->data].gpio);
> +
> + gpiod_set_value_cansleep(gpiod, value);
> +}
> +
> +static void loongson_i2c_set_clock(void *i2c, int value)
> +{
> + struct loongson_i2c *li2c = i2c;
> + struct gpio_desc *gpiod = gpio_to_desc(i2c_gpios[li2c->clock].gpio);
> +
> + gpiod_set_value_cansleep(gpiod, value);
> +}
> +
> +static int loongson_i2c_get_data(void *i2c)
> +{
> + struct loongson_i2c *li2c = i2c;
> + struct gpio_desc *gpiod = gpio_to_desc(i2c_gpios[li2c->data].gpio);
> +
> + return gpiod_get_value_cansleep(gpiod);
> +}
> +
> +static int loongson_i2c_get_clock(void *i2c)
> +{
> + struct loongson_i2c *li2c = i2c;
> + struct gpio_desc *gpiod = gpio_to_desc(i2c_gpios[li2c->clock].gpio);
> +
> + return gpiod_get_value_cansleep(gpiod);
> +}
> +
> +static int loongson_i2c_create(struct loongson_i2c *li2c, const char *name)
> +{
> + int ret;
> + unsigned int i2c_num;
> + struct i2c_client *i2c_cli;
> + struct i2c_adapter *i2c_adapter;
> + struct i2c_board_info i2c_info;
> + struct i2c_algo_bit_data *i2c_algo_data;
> + struct device *dev;
> +
> + dev = &li2c->adapter->dev;
> + i2c_num = li2c->i2c_id;
> + i2c_adapter = kzalloc(sizeof(struct i2c_adapter), GFP_KERNEL);
> + if (IS_ERR(i2c_adapter)) {
> + ret = PTR_ERR(i2c_adapter);
> + goto error_mem;
> + }
> + i2c_algo_data = kzalloc(sizeof(struct i2c_algo_bit_data), GFP_KERNEL);
> + if (IS_ERR(i2c_algo_data)) {
> + ret = PTR_ERR(i2c_algo_data);
> + goto error_mem;
> + }
> +
> + i2c_adapter->owner = THIS_MODULE;
> + i2c_adapter->class = I2C_CLASS_DDC;
> + i2c_adapter->algo_data = i2c_algo_data;
> + i2c_adapter->nr = i2c_num;
> + snprintf(i2c_adapter->name, sizeof(i2c_adapter->name), "%s%d", name, i2c_num - DC_I2C_BASE);
> + li2c->data = "" % DC_I2C_BASE * 2;
> + li2c->clock = i2c_num % DC_I2C_BASE * 2 + 1;
> + DRM_INFO("Created i2c-%d, sda=%d, scl=%d\n", i2c_num, li2c->data, li2c->clock);
> + if (gpio_cansleep(i2c_gpios[li2c->data].gpio) || gpio_cansleep(i2c_gpios[li2c->clock].gpio))
> + dev_warn(dev, "Slow GPIO pins might wreak havoc I2C timing\n");
> + i2c_algo_data->setsda = loongson_i2c_set_data;
> + i2c_algo_data->setscl = loongson_i2c_set_clock;
> + i2c_algo_data->getsda = loongson_i2c_get_data;
> + i2c_algo_data->getscl = loongson_i2c_get_clock;
> + i2c_algo_data->udelay = DC_I2C_TON;
> + i2c_algo_data->timeout = usecs_to_jiffies(2200); /* from VESA */
> + ret = i2c_bit_add_numbered_bus(i2c_adapter);
> + if (ret) {
> + DRM_ERROR("Failed to register i2c algo-bit adapter %s\n", i2c_adapter->name);
> + kfree(i2c_adapter);
> + i2c_adapter = NULL;
> + }
> +
> + li2c->adapter = i2c_adapter;
> + i2c_algo_data->data = "">
> + i2c_set_adapdata(li2c->adapter, li2c);
> + DRM_INFO("Register i2c algo-bit adapter [%s]\n", i2c_adapter->name);
> +
> + memset(&i2c_info, 0, sizeof(struct i2c_board_info));
> + strncpy(i2c_info.type, name, I2C_NAME_SIZE);
> + i2c_info.addr = DDC_ADDR;
> + i2c_cli = i2c_new_client_device(i2c_adapter, &i2c_info);
> + if (i2c_cli == NULL) {
> + DRM_ERROR("Failed to create i2c adapter\n");
> + return -EBUSY;
> + }
> + li2c->init = true;
> + return 0;
> +
> +error_mem:
> + DRM_ERROR("Failed to malloc memory for loongson i2c\n");
> + return ret;
> +}
> +
> +static int loongson_i2c_add(struct loongson_device *ldev, const char *name)
> +{
> + int i;
> +
> + for (i = 0; i < LS_MAX_I2C_BUS; i++) {
> + if (ldev->i2c_bus[i].use) {
> + loongson_i2c_create(&ldev->i2c_bus[i], name);
> + } else {
> + DRM_DEBUG_DRIVER("i2c_bus[%d] not use\n", i);
> + return -ENODEV;
> + }
> + }
> + return 0;
> +}
> +
> +int loongson_dc_gpio_init(struct loongson_device *ldev)
> +{
> + int ret;
> + struct gpio_chip *chip;
> +
> + chip = &ldev->chip;
> + chip->label = "ls7a-dc-gpio";
> + chip->base = LS7A_DC_GPIO_BASE;
> + chip->ngpio = 4;
> + chip->parent = ldev->dev->dev;
> + chip->request = ls_dc_gpio_request;
> + chip->direction_input = ls_dc_gpio_dir_input;
> + chip->direction_output = ls_dc_gpio_dir_output;
> + chip->set = ls_dc_gpio_set;
> + chip->get = ls_dc_gpio_get;
> + chip->can_sleep = false;
> +
> + ret = devm_gpiochip_add_data(ldev->dev->dev, chip, ldev);
> + if (ret) {
> + DRM_ERROR("Failed to register ls7a dc gpio driver\n");
> + return -ENODEV;
> + }
> + DRM_INFO("Registered ls7a dc gpio driver\n");
> +
> + return 0;
> +}
> +
> +int loongson_i2c_init(struct loongson_device *ldev)
> +{
> + int ret;
> +
> + ret = gpio_request_array(i2c_gpios, ARRAY_SIZE(i2c_gpios));
> + if (ret) {
> + DRM_ERROR("Failed to request gpio array i2c_gpios\n");
> + return -ENODEV;
> + }
> +
> + ldev->i2c_bus[0].i2c_id = 6;
> + ldev->i2c_bus[0].use = true;
> + ldev->i2c_bus[1].i2c_id = 7;
> + ldev->i2c_bus[1].use = true;
> +
> + loongson_i2c_add(ldev, DC_I2C_NAME);
> +
> + return 0;
> +}
> +
> +struct loongson_i2c *loongson_i2c_bus_match(struct loongson_device *ldev, u32 i2c_id)
> +{
> + u32 i;
> + struct loongson_i2c *match = NULL, *tables;
> +
> + tables = ldev->i2c_bus;
> +
> + for (i = 0; i < LS_MAX_I2C_BUS; i++) {
> + if (tables->i2c_id == i2c_id && tables->init == true) {
> + match = tables;
> + break;
> + }
> +
> + tables++;
> + }
> +
> + return match;
> +}
> diff --git a/drivers/gpu/drm/loongson/loongson_i2c.h b/drivers/gpu/drm/loongson/loongson_i2c.h
> new file mode 100644
> index 000000000..164619007
> --- /dev/null
> +++ b/drivers/gpu/drm/loongson/loongson_i2c.h
> @@ -0,0 +1,40 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +
> +#ifndef __LOONGSON_I2C_H__
> +#define __LOONGSON_I2C_H__
> +
> +#include <linux/i2c.h>
> +#include <linux/i2c-algo-bit.h>
> +#include <linux/gpio/driver.h>
> +#include <drm/drm_edid.h>
> +
> +// Modify this marco to config i2c bus speed, bus_freq = 500 / T
> +// Eg: i2c_bus_freq=100k when T=5
> +#define DC_I2C_TON 5
> +#define DC_I2C_BASE 6
> +#define DC_I2C_NAME "ls_dc_i2c"
> +#define LS_MAX_I2C_BUS 16
> +
> +/* Loongson 7A display controller proprietary GPIOs */
> +#define LS7A_DC_GPIO_BASE 73
> +#define DC_GPIO_0 (73)
> +#define DC_GPIO_1 (74)
> +#define DC_GPIO_2 (75)
> +#define DC_GPIO_3 (76)
> +#define LS7A_DC_GPIO_CFG_OFFSET (0x1660)
> +#define LS7A_DC_GPIO_IN_OFFSET (0x1650)
> +#define LS7A_DC_GPIO_OUT_OFFSET (0x1650)
> +
> +struct loongson_device;
> +struct loongson_i2c {
> + struct i2c_adapter *adapter;
> + u32 data, clock;
> + bool use, init;
> + u32 i2c_id;
> +};
> +
> +struct loongson_i2c *loongson_i2c_bus_match(struct loongson_device *ldev,
> + u32 i2c_id);
> +int loongson_i2c_init(struct loongson_device *ldev);
> +
> +#endif /* __LOONGSON_I2C_H__ */
> --
> 2.27.0
------------------------------
Loongson LiChenyang
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