[PATCH v2] drm/loongson: Add DDC support for loongson display controller

lichenyang liplay at 163.com
Fri Mar 19 09:24:40 UTC 2021


Hi, sunhao.




> 

> Add GPIO and I2C driver to detect connector and fetch EDID via DDC.

> 
It's even better to add what V2 has changed.
> Signed-off-by: Hao Sun <sunhao at loongson.cn>

> ---

>  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;

> +}
can use drm_get_edid get edid,you can delete get_edid_i2c and loongson_do_probe_ddc_edid

> +

>  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 = i2c_num % 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 = li2c;

> +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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