Hi lichenyang,
On Fri, Jul 30, 2021 at 05:41:47PM +0800, lichenyang wrote:
> Implement use GPIO and I2C driver to detect connector
> and fetch EDID via DDC.
>
> v3:
> - Change some driver log to the drm_ version.
>
> v2:
> - Optimize the error handling process.
> - Delete loongson_i2c_bus_match and loongson_i2c_add function.
> - Optimize part of the code flow.
>
> Signed-off-by: lichenyang <lichenyang(a)loongson.cn>
Thanks for keeping me in the loop on this patch series.
In general the code looks pretty clean and well structured which makes
review easier - good.
As already said this driver should be implemented as a bridge which
would make the integration with the display driver simpler and more
straightforward.
When implementing this as a bridge driver there will be no drm_device,
so logging will need to use dev_err and friends.
Try to run the driver(s) with sparse:
make C=2 drivers/gpu/drm/loongson/
I think this will give you a few warnigns to fix.
Likewise use checkpatch --strict as this often resutls in a few easy to
fix warnings.
Last try to build with W=1 and fix warnings too.
The above goes for all files in this driver as we would like to have all
new drivers W=1, sparse and checkpatch clean.
Some more specific comments in the following,
Sam
> ---
> drivers/gpu/drm/loongson/Makefile | 1 +
> drivers/gpu/drm/loongson/loongson_connector.c | 59 ++++-
> drivers/gpu/drm/loongson/loongson_drv.c | 15 +-
> drivers/gpu/drm/loongson/loongson_drv.h | 11 +
> drivers/gpu/drm/loongson/loongson_i2c.c | 249 ++++++++++++++++++
> drivers/gpu/drm/loongson/loongson_i2c.h | 36 +++
> 6 files changed, 366 insertions(+), 5 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 d73ad44fe1d5..a842e85cf6ca 100644
> --- a/drivers/gpu/drm/loongson/Makefile
> +++ b/drivers/gpu/drm/loongson/Makefile
> @@ -10,5 +10,6 @@ loongson-y := loongson_connector.o \
> loongson_device.o \
> loongson_drv.o \
> loongson_encoder.o \
> + loongson_i2c.o \
> loongson_plane.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 a4762d8f9987..bdf7d651d6d1 100644
> --- a/drivers/gpu/drm/loongson/loongson_connector.c
> +++ b/drivers/gpu/drm/loongson/loongson_connector.c
> @@ -4,12 +4,56 @@
>
> static int loongson_get_modes(struct drm_connector *connector)
> {
> - int count;
> + struct drm_device *dev = connector->dev;
> + struct loongson_connector *lconnector =
> + to_loongson_connector(connector);
> + struct i2c_adapter *adapter = lconnector->i2c->adapter;
> + struct edid *edid = NULL;
> + u32 ret;
>
> - count = drm_add_modes_noedid(connector, 1920, 1080);
> - drm_set_preferred_mode(connector, 1024, 768);
> + edid = drm_get_edid(connector, adapter);
> + if (edid) {
> + drm_connector_update_edid_property(connector, edid);
> + ret = drm_add_edid_modes(connector, edid);
> + } else {
> + drm_warn(dev, "Failed to read EDID\n");
> + ret = drm_add_modes_noedid(connector, 1920, 1080);
> + drm_set_preferred_mode(connector, 1024, 768);
> + }
>
> - return count;
> + return ret;
> +}
> +
> +static bool is_connected(struct loongson_connector *lconnector)
> +{
> + struct i2c_adapter *adapter = lconnector->i2c->adapter;
> + unsigned char start = 0x0;
> + struct i2c_msg msgs = {
> + .addr = DDC_ADDR,
> + .flags = 0,
> + .len = 1,
> + .buf = &start,
> + };
> +
> + if (!lconnector->i2c)
> + return false;
> +
> + if (i2c_transfer(adapter, &msgs, 1) != 1)
> + return false;
> +
> + return true;
> +}
> +
> +static enum drm_connector_status
> +loongson_detect(struct drm_connector *connector, bool force)
> +{
> + struct loongson_connector *lconnector =
> + to_loongson_connector(connector);
> +
> + if (is_connected(lconnector))
> + return connector_status_connected;
> +
> + return connector_status_disconnected;
> }
>
> static const struct drm_connector_helper_funcs loongson_connector_helper = {
> @@ -17,6 +61,7 @@ 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,
> @@ -36,6 +81,12 @@ int loongson_connector_init(struct loongson_device *ldev, int index)
>
> lconnector->ldev = ldev;
> lconnector->id = index;
> + lconnector->i2c_id = index;
> +
> + lconnector->i2c = &ldev->i2c_bus[lconnector->i2c_id];
> + if (!lconnector->i2c)
> + drm_err(dev, "connector-%d match i2c-%d err\n", index,
> + lconnector->i2c_id);
>
> ldev->mode_info[index].connector = lconnector;
> connector = &lconnector->base;
> diff --git a/drivers/gpu/drm/loongson/loongson_drv.c b/drivers/gpu/drm/loongson/loongson_drv.c
> index 2224a03adc1a..4c02cbe1a5e6 100644
> --- a/drivers/gpu/drm/loongson/loongson_drv.c
> +++ b/drivers/gpu/drm/loongson/loongson_drv.c
> @@ -12,9 +12,10 @@
>
> /* 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,
> @@ -76,6 +77,18 @@ static int loongson_device_init(struct drm_device *dev)
> if (!ldev->io)
> return -ENOMEM;
>
> + ret = loongson_dc_gpio_init(ldev);
> + if (ret) {
> + drm_err(dev, "Failed to initialize dc gpios\n");
loongson_dc_gpio_init() already printed an error message, no need to do
it twice.
> + return ret;
> + }
> +
> + ret = loongson_i2c_init(ldev);
Make loongson_i2c_init() always print an error message so you can drop
this drm_err.
> + if (ret) {
> + drm_err(dev, "Failed to initialize dc i2c err %d\n", ret);
> + return ret;
> + }
> +
> drm_info(dev, "DC mmio base 0x%llx size 0x%llx io 0x%llx\n",
> mmio_base, mmio_size, *(u64 *)ldev->io);
> drm_info(dev, "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 75965d198212..67d7d61d93f5 100644
> --- a/drivers/gpu/drm/loongson/loongson_drv.h
> +++ b/drivers/gpu/drm/loongson/loongson_drv.h
> @@ -19,6 +19,8 @@
> #include <drm/drm_plane.h>
> #include <drm/drm_plane_helper.h>
>
> +#include "loongson_i2c.h"
> +
> /* General customization:
> */
> #define DRIVER_AUTHOR "Loongson graphics driver team"
> @@ -28,6 +30,7 @@
>
> #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
> @@ -96,6 +99,8 @@ struct loongson_encoder {
> struct loongson_connector {
> struct drm_connector base;
> struct loongson_device *ldev;
> + struct loongson_i2c *i2c;
> + u16 i2c_id;
> u16 id;
> u32 type;
> };
> @@ -119,6 +124,9 @@ 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;
> };
>
> static inline struct loongson_device *to_loongson_device(struct drm_device *dev)
> @@ -138,6 +146,9 @@ int loongson_encoder_init(struct loongson_device *ldev, int index);
> /* plane */
> struct loongson_plane *loongson_plane_init(struct drm_device *dev, int index);
>
> +/* i2c */
> +int loongson_dc_gpio_init(struct loongson_device *ldev);
> +
> /* device */
> u32 loongson_gpu_offset(struct drm_plane_state *state,
> struct loongson_device *dev);
> diff --git a/drivers/gpu/drm/loongson/loongson_i2c.c b/drivers/gpu/drm/loongson/loongson_i2c.c
> new file mode 100644
> index 000000000000..d3a9830afbed
> --- /dev/null
> +++ b/drivers/gpu/drm/loongson/loongson_i2c.c
> @@ -0,0 +1,249 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +
> +#include "linux/gpio.h"
> +#include <linux/gpio/consumer.h>
> +
> +#include "loongson_drv.h"
> +//#include "loongson_i2c.h"
I am sure this include should be present.
> +
> +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" },
> +};
This looks like HW configuration that should be read from a DT file and
not hardcoded in the driver.
> +
> +static inline void __dc_gpio_set_dir(struct loongson_device *ldev,
> + unsigned int pin, int input)
I personally dislike the "__" prefixed, but this is bikeshedding so feel
free to ignore.
> +{
> + u32 temp;
> +
> + temp = ls7a_mm_rreg(ldev, LS7A_DC_GPIO_CFG_OFFSET);
Maybe use a regmap for the mm_rreg stuff?
> +
> + if (input)
> + temp |= 1UL << pin;
> + else
> + temp &= ~(1UL << pin);
> +
> + ls7a_mm_wreg(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 = ls7a_mm_rreg(ldev, LS7A_DC_GPIO_OUT_OFFSET);
> +
> + if (high)
> + temp |= 1UL << pin;
> + else
> + temp &= ~(1UL << pin);
> +
> + ls7a_mm_wreg(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;
Add empty line
> + return 0;
> +}
> +
> +static int ls_dc_gpio_dir_input(struct gpio_chip *chip, unsigned int pin)
> +{
> + struct loongson_device *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 =
> + 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 =
> + 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)
> +{
> + struct loongson_device *ldev =
> + container_of(chip, struct loongson_device, chip);
> + u32 val = ls7a_mm_rreg(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_device *ldev,
> + struct loongson_i2c *li2c, const char *name)
> +{
> + int ret;
> + unsigned int i2c_num;
> + struct drm_device *dev = &ldev->dev;
> + struct i2c_client *i2c_cli;
> + struct i2c_adapter *i2c_adapter;
> + struct i2c_algo_bit_data *i2c_algo_data;
> + const struct i2c_board_info i2c_info = {
> + .type = "ddc-dev",
> + .addr = DDC_ADDR,
> + .flags = I2C_CLASS_DDC,
> + };
> +
> + i2c_num = li2c->i2c_id;
> + i2c_adapter = kzalloc(sizeof(struct i2c_adapter), GFP_KERNEL);
Can you use some devm_kzalloc() here?
Then you do not need to free the memory and unwinding is simpler.
> + if (!i2c_adapter)
> + return -ENOMEM;
> +
> + i2c_algo_data = kzalloc(sizeof(struct i2c_algo_bit_data), GFP_KERNEL);
devm_ again?
> + if (!i2c_algo_data) {
> + ret = -ENOMEM;
> + goto free_adapter;
> + }
> +
> + i2c_adapter->owner = THIS_MODULE;
> + i2c_adapter->class = I2C_CLASS_DDC;
> + i2c_adapter->algo_data = i2c_algo_data;
> + i2c_adapter->dev.parent = dev->dev;
> + i2c_adapter->nr = -1;
> + snprintf(i2c_adapter->name, sizeof(i2c_adapter->name), "%s%d",
> + name, i2c_num);
> +
> + li2c->data = i2c_num * 2;
> + li2c->clock = i2c_num * 2 + 1;
> + DRM_INFO("Created i2c-%d, sda=%d, scl=%d\n",
> + i2c_num, li2c->data, li2c->clock);
> +
> + 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);
> +
> + ret = i2c_bit_add_numbered_bus(i2c_adapter);
> + if (ret)
> + goto free_algo_data;
> +
> + 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);
> +
> + i2c_cli = i2c_new_client_device(i2c_adapter, &i2c_info);
> + if (IS_ERR(i2c_cli)) {
> + ret = PTR_ERR(i2c_cli);
> + goto remove_i2c_adapter;
> + }
> +
> + return 0;
> +
> +remove_i2c_adapter:
> + drm_err(dev, "Failed to create i2c client\n");
> + i2c_del_adapter(i2c_adapter);
> +free_algo_data:
> + drm_err(dev, "Failed to register i2c adapter %s\n", i2c_adapter->name);
> + kfree(i2c_algo_data);
> +free_adapter:
> + kfree(i2c_adapter);
> +
> + return ret;
> +}
> +
> +int loongson_dc_gpio_init(struct loongson_device *ldev)
> +{
> + struct drm_device *dev = &ldev->dev;
> + struct gpio_chip *chip = &ldev->chip;
> + int ret;
> +
> + chip->label = "ls7a-dc-gpio";
> + chip->base = LS7A_DC_GPIO_BASE;
> + chip->ngpio = 4;
> + chip->parent = 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(dev->dev, chip, ldev);
> + if (ret) {
> + drm_err(dev, "Failed to register ls7a dc gpio driver\n");
> + return ret;
> + }
> + DRM_INFO("Registered ls7a dc gpio driver\n");
> +
> + return 0;
> +}
> +
> +int loongson_i2c_init(struct loongson_device *ldev)
> +{
> + struct drm_device *dev = &ldev->dev;
> + int ret;
> + int i;
> +
> + ret = gpio_request_array(i2c_gpios, ARRAY_SIZE(i2c_gpios));
> + if (ret) {
> + drm_err(dev, "Failed to request gpio array i2c_gpios\n");
> + return -ENODEV;
> + }
> +
> + ldev->i2c_bus[0].i2c_id = 0;
> + ldev->i2c_bus[1].i2c_id = 1;
> +
> + for (i = 0; i < 2; i++) {
> + ret = loongson_i2c_create(ldev, &ldev->i2c_bus[i], DC_I2C_NAME);
> + if (ret)
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> diff --git a/drivers/gpu/drm/loongson/loongson_i2c.h b/drivers/gpu/drm/loongson/loongson_i2c.h
> new file mode 100644
> index 000000000000..95cc961bc968
> --- /dev/null
> +++ b/drivers/gpu/drm/loongson/loongson_i2c.h
> @@ -0,0 +1,36 @@
> +/* 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>
sort includes alphabetically - and empty lines between linux/* and drm/*
> +#include <drm/drm_edid.h>
> +
> +#define DC_I2C_TON 5
> +#define DC_I2C_NAME "ls_dc_i2c"
> +#define LS_MAX_I2C_BUS 2
> +
> +/* 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 loongson_device *ldev;
> + struct i2c_adapter *adapter;
> + u32 data, clock;
> + bool use;
use is not used in the code - drop.
> + u32 i2c_id;
> +};
> +
> +int loongson_i2c_init(struct loongson_device *ldev);
> +
> +#endif /* __LOONGSON_I2C_H__ */
> --
> 2.32.0
