Hi,

On Tue, Apr 28, 2020 at 08:07:17PM +0200, Robert Foss wrote:
> Add match table, enable ov8856_probe() to support
> both ACPI and DT modes.
> 
> ACPI and DT modes are primarily distinguished from
> each other by relying on devm_XXX_get_optional()
> will return NULL instead of a reference for the
> desired managed resource.
> 
> Signed-off-by: Robert Foss <[email protected]>
> ---
> 
> - Changes since v4:
>   * Maxime & Sakari: Switch to clock-frequency
> 
> - Changes since v3:
>   * Remove redundant {}-brackets
>   * Compare xvclk_rate to 5% tolerance
>   * Andy: Use dev_fwnode()
>   * Andy: Use %pe instead of %ld + PTR_ERR()
>   * Andy: Invert reset_gpio logic
>   * Andy: Remove dev_dbg() from failing reset_gpio setup
>   * Andy: Use dev_err for logging for failures
>   * Andy: Remove dev_warn from EDEFER/regulator error path
>   * Andy & Sakari: Replaced GPIOD_OUT_XXX with 0/1
>   * Maxime & Sakari: Verify clock frequency from DT
>   * Sakari: Verify the 'xvclk_rate' is set correctly for ACPI/DT devices
>   * Sakari: Remove duplicate ov8856->dev assignment
> 
> - Changes since v2:
>   * Added "struct device *dev" member to struct ov8856
>   * Andy: Switch to optional version of devm_gpiod_get
>   * Andy: Switch to optional version of devm_clk_get
>   * Fabio: Add reset sleep period
>   * Sakari: Unify defines for 19.2Mhz
>   * Sakari: Remove 24Mhz clock, since it isn't needed for supported modes
>   * Sakari: Replace dev_info() with dev_dbg()
>   * Sakari: Switch induction variable type to unsigned
>   * Sakari: Don't wait for reset_gpio when in ACPI mode
>   * Sakari: Pull reset GPIO high on power on failure
>   * Sakari: Add power on/off to resume/suspend
>   * Sakari: Fix indentation
>   * Sakari: Power off during ov8856_remove()
>   * Sakari: Don't sleep during power-on in ACPI mode
>   * Sakari: Switch to getting xvclk from clk_get_rate
> 
> - Changes since v1:
>   * Andy & Sakari: Make XVCLK optional since to not break ACPI
>   * Fabio: Change n_shutdown_gpio name to reset_gpio
>   * Fabio: Invert reset_gpio due to GPIO_ACTIVE_HIGH -> GPIO_ACTIVE_LOW change
>   * Fabio: Remove empty line
>   * Fabio: Remove real error from devm_gpiod_get() failures
>   * Sakari: ARRAY_SIZE() directly instead of through OV8856_NUM_SUPPLIES
>   * Sakari: Use XVCLK rate as provided by DT
> 
>  drivers/media/i2c/ov8856.c | 139 +++++++++++++++++++++++++++++++++----
>  1 file changed, 126 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/media/i2c/ov8856.c b/drivers/media/i2c/ov8856.c
> index 8655842af275..48b02b8d205f 100644
> --- a/drivers/media/i2c/ov8856.c
> +++ b/drivers/media/i2c/ov8856.c
> @@ -3,10 +3,13 @@
>  
>  #include <asm/unaligned.h>
>  #include <linux/acpi.h>
> +#include <linux/clk.h>
>  #include <linux/delay.h>
> +#include <linux/gpio/consumer.h>
>  #include <linux/i2c.h>
>  #include <linux/module.h>
>  #include <linux/pm_runtime.h>
> +#include <linux/regulator/consumer.h>
>  #include <media/v4l2-ctrls.h>
>  #include <media/v4l2-device.h>
>  #include <media/v4l2-fwnode.h>
> @@ -18,7 +21,7 @@
>  #define OV8856_LINK_FREQ_360MHZ              360000000ULL
>  #define OV8856_LINK_FREQ_180MHZ              180000000ULL
>  #define OV8856_SCLK                  144000000ULL
> -#define OV8856_MCLK                  19200000
> +#define OV8856_XVCLK_19_2            19200000
>  #define OV8856_DATA_LANES            4
>  #define OV8856_RGB_DEPTH             10
>  
> @@ -64,6 +67,12 @@
>  
>  #define to_ov8856(_sd)                       container_of(_sd, struct 
> ov8856, sd)
>  
> +static const char * const ov8856_supply_names[] = {
> +     "dovdd",        /* Digital I/O power */
> +     "avdd",         /* Analog power */
> +     "dvdd",         /* Digital core power */
> +};
> +
>  enum {
>       OV8856_LINK_FREQ_720MBPS,
>       OV8856_LINK_FREQ_360MBPS,
> @@ -566,6 +575,11 @@ struct ov8856 {
>       struct media_pad pad;
>       struct v4l2_ctrl_handler ctrl_handler;
>  
> +     struct device           *dev;
> +     struct clk              *xvclk;
> +     struct gpio_desc        *reset_gpio;
> +     struct regulator_bulk_data supplies[ARRAY_SIZE(ov8856_supply_names)];
> +
>       /* V4L2 Controls */
>       struct v4l2_ctrl *link_freq;
>       struct v4l2_ctrl *pixel_rate;
> @@ -908,6 +922,52 @@ static int ov8856_set_stream(struct v4l2_subdev *sd, int 
> enable)
>       return ret;
>  }
>  
> +static int __ov8856_power_on(struct ov8856 *ov8856)
> +{
> +     struct i2c_client *client = v4l2_get_subdevdata(&ov8856->sd);
> +     int ret;
> +
> +     ret = clk_prepare_enable(ov8856->xvclk);
> +     if (ret < 0) {
> +             dev_err(&client->dev, "failed to enable xvclk\n");
> +             return ret;
> +     }
> +
> +     if (is_acpi_node(dev_fwnode(ov8856->dev)))
> +             return 0;
> +
> +     if (ov8856->reset_gpio) {
> +             gpiod_set_value_cansleep(ov8856->reset_gpio, 1);
> +             usleep_range(1000, 2000);
> +     }
> +
> +     ret = regulator_bulk_enable(ARRAY_SIZE(ov8856_supply_names),
> +                                 ov8856->supplies);
> +     if (ret < 0) {
> +             dev_err(&client->dev, "failed to enable regulators\n");
> +             goto disable_clk;
> +     }
> +
> +     gpiod_set_value_cansleep(ov8856->reset_gpio, 0);
> +     usleep_range(1500, 1800);
> +
> +     return 0;
> +
> +disable_clk:
> +     gpiod_set_value_cansleep(ov8856->reset_gpio, 1);
> +     clk_disable_unprepare(ov8856->xvclk);
> +
> +     return ret;
> +}
> +
> +static void __ov8856_power_off(struct ov8856 *ov8856)
> +{
> +     gpiod_set_value_cansleep(ov8856->reset_gpio, 1);
> +     regulator_bulk_disable(ARRAY_SIZE(ov8856_supply_names),
> +                            ov8856->supplies);
> +     clk_disable_unprepare(ov8856->xvclk);
> +}
> +
>  static int __maybe_unused ov8856_suspend(struct device *dev)
>  {
>       struct i2c_client *client = to_i2c_client(dev);
> @@ -918,6 +978,7 @@ static int __maybe_unused ov8856_suspend(struct device 
> *dev)
>       if (ov8856->streaming)
>               ov8856_stop_streaming(ov8856);
>  
> +     __ov8856_power_off(ov8856);
>       mutex_unlock(&ov8856->mutex);
>  
>       return 0;
> @@ -931,6 +992,8 @@ static int __maybe_unused ov8856_resume(struct device 
> *dev)
>       int ret;
>  
>       mutex_lock(&ov8856->mutex);
> +
> +     __ov8856_power_on(ov8856);
>       if (ov8856->streaming) {
>               ret = ov8856_start_streaming(ov8856);
>               if (ret) {
> @@ -1092,29 +1155,58 @@ static int ov8856_identify_module(struct ov8856 
> *ov8856)
>       return 0;
>  }
>  
> -static int ov8856_check_hwcfg(struct device *dev)
> +static int ov8856_get_hwcfg(struct ov8856 *ov8856)
>  {
> +     struct device *dev = ov8856->dev;
>       struct fwnode_handle *ep;
>       struct fwnode_handle *fwnode = dev_fwnode(dev);
>       struct v4l2_fwnode_endpoint bus_cfg = {
>               .bus_type = V4L2_MBUS_CSI2_DPHY
>       };
> -     u32 mclk;
> +     u32 xvclk_rate;
>       int ret;
>       unsigned int i, j;
>  
>       if (!fwnode)
>               return -ENXIO;
>  
> -     ret = fwnode_property_read_u32(fwnode, "clock-frequency", &mclk);
> +     ret = fwnode_property_read_u32(fwnode, "clock-frequency",
> +             &xvclk_rate);
>       if (ret)
>               return ret;
>  
> -     if (mclk != OV8856_MCLK) {
> -             dev_err(dev, "external clock %d is not supported", mclk);
> +     if (!is_acpi_node(fwnode)) {
> +             ov8856->xvclk = devm_clk_get(dev, "xvclk");
> +             if (IS_ERR(ov8856->xvclk)) {
> +                     dev_err(dev, "could not get xvclk clock (%pe)\n",
> +                                     ov8856->xvclk);
> +                     return PTR_ERR(ov8856->xvclk);
> +             }
> +
> +             clk_set_rate(ov8856->xvclk, xvclk_rate);
> +             xvclk_rate = clk_get_rate(ov8856->xvclk);
> +     }
> +
> +     /* external clock must be 19.2MHz, allow 5% tolerance */

Where is that 5% tolerance coming from? Experimentations, datasheets, something
that looks good enough? Either way, this should be in the comment.

Maxime

Attachment: signature.asc
Description: PGP signature

Reply via email to