[PATCH] drm/loongson: Add DDC support for loongson display controller
Hao Sun
sunhao at loongson.cn
Mon Jan 4 07:15:35 UTC 2021
Add GPIO and I2C driver to detect connector and fetch EDID via DDC.
Signed-off-by: Hao Sun <sunhao at loongson.cn>
---
drivers/gpu/drm/loongson/Makefile | 3 +-
drivers/gpu/drm/loongson/loongson_connector.c | 121 +++++++-
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, 447 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 22d063953b78..773b806e99a2 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 7bf1e40318c3..955a0ac1719a 100644
--- a/drivers/gpu/drm/loongson/loongson_connector.c
+++ b/drivers/gpu/drm/loongson/loongson_connector.c
@@ -2,21 +2,126 @@
#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;
- count = drm_add_modes_noedid(connector, 1920, 1080);
- drm_set_preferred_mode(connector, 1024, 768);
+ success = get_edid_i2c(lconnector, edid);
- return count;
+ 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;
+
+ 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 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 = {
.get_modes = loongson_get_modes,
};
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 +142,17 @@ 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 7c5c51341d91..6d0dc5db902c 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 - riginal.
+ * 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 mmio_size 0x%llx io 0x%x\n",
mmio_base, mmio_size, *(int *)ldev->io);
DRM_INFO("GPU vram_start = 0x%x vram_size = 0x%x\n",
diff --git a/drivers/gpu/drm/loongson/loongson_drv.h b/drivers/gpu/drm/loongson/loongson_drv.h
index da3e5673eb2b..0dfc48375db0 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
@@ -85,8 +87,10 @@ 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 {
@@ -109,6 +113,9 @@ struct loongson_device {
u32 num_crtc;
struct loongson_mode_info mode_info[2];
struct pci_dev *gpu_pdev; /* loongson 7A gpu device info */
+
+ struct loongson_i2c i2c_bus[LS_MAX_I2C_BUS];
+ struct gpio_chip chip;
};
/* crtc */
@@ -123,6 +130,9 @@ 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 ls_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 000000000000..b34c9e3c45ca
--- /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 000000000000..164619007c0a
--- /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__ */
--
2.25.1
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