Commit e1a4b3a7 authored by Hans de Goede's avatar Hans de Goede Committed by Mauro Carvalho Chehab
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media: atomisp: gc0310: Simplify gc0310_write_reg_array() 



Remove the complex optimization to send multiple registers in
one i2c-transfer. None of the other sensor drivers are doing this
and the reg-lists are only used once at stream-start time, so
this does not need to be highly optimized.

Reviewed-by: default avatarAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@kernel.org>
parent bfe06aee

drivers/staging/media/atomisp/i2c/atomisp-gc0310.c

+3 −84
Original line number Diff line number Diff line
@@ -135,100 +135,19 @@ static int gc0310_write_reg(struct i2c_client *client, u16 data_length, 
 * @client: i2c driver client structure

 * @reglist: list of registers to be written

 * @count: number of register, value pairs in the list

 *

 * This function initializes a list of registers. When consecutive addresses

 * are found in a row on the list, this function creates a buffer and sends

 * consecutive data in a single i2c_transfer().

 *

 * __gc0310_flush_reg_array, __gc0310_buf_reg_array() and

 * __gc0310_write_reg_is_consecutive() are internal functions to

 * gc0310_write_reg_array_fast() and should be not used anywhere else.

 *

 */



static int __gc0310_flush_reg_array(struct i2c_client *client,

				    struct gc0310_write_ctrl *ctrl)

{

	u16 size;



	if (ctrl->index == 0)

		return 0;



	size = sizeof(u8) + ctrl->index; /* 8-bit address + data */

	ctrl->buffer.addr = (u8)(ctrl->buffer.addr);

	ctrl->index = 0;



	return gc0310_i2c_write(client, size, (u8 *)&ctrl->buffer);

}



static int __gc0310_buf_reg_array(struct i2c_client *client,

				  struct gc0310_write_ctrl *ctrl,

				  const struct gc0310_reg *next)

{

	int size;



	switch (next->type) {

	case GC0310_8BIT:

		size = 1;

		ctrl->buffer.data[ctrl->index] = (u8)next->val;

		break;

	default:

		return -EINVAL;

	}



	/* When first item is added, we need to store its starting address */

	if (ctrl->index == 0)

		ctrl->buffer.addr = next->reg;



	ctrl->index += size;



	/*

	 * Buffer cannot guarantee free space for u32? Better flush it to avoid

	 * possible lack of memory for next item.

	 */

	if (ctrl->index + sizeof(u8) >= GC0310_MAX_WRITE_BUF_SIZE)

		return __gc0310_flush_reg_array(client, ctrl);



	return 0;

}



static int __gc0310_write_reg_is_consecutive(struct i2c_client *client,

					     struct gc0310_write_ctrl *ctrl,

					     const struct gc0310_reg *next)

{

	if (ctrl->index == 0)

		return 1;



	return ctrl->buffer.addr + ctrl->index == next->reg;

}



static int gc0310_write_reg_array(struct i2c_client *client,

				  const struct gc0310_reg *reglist, int count)

{

	struct gc0310_write_ctrl ctrl;

	int i, err;



	ctrl.index = 0;

	for (i = 0; i < count; i++) {

		/*

		 * If next address is not consecutive, data needs to be

		 * flushed before proceed.

		 */

		if (!__gc0310_write_reg_is_consecutive(client, &ctrl,

						       &reglist[i])) {

			err = __gc0310_flush_reg_array(client, &ctrl);

		err = gc0310_write_reg(client, GC0310_8BIT, reglist[i].reg, reglist[i].val);

		if (err)

			return err;

	}

		err = __gc0310_buf_reg_array(client, &ctrl, &reglist[i]);

		if (err) {

			dev_err(&client->dev, "%s: write error, aborted\n",

				__func__);

			return err;

		}

	}



	return __gc0310_flush_reg_array(client, &ctrl);

	return 0;

}



static int gc0310_set_gain(struct v4l2_subdev *sd, int gain)

drivers/staging/media/atomisp/i2c/gc0310.h

+0 −12
Original line number Diff line number Diff line
@@ -158,18 +158,6 @@ struct gc0310_reg { 


#define to_gc0310_sensor(x) container_of(x, struct gc0310_device, sd)



#define GC0310_MAX_WRITE_BUF_SIZE	30



struct gc0310_write_buffer {

	u8 addr;

	u8 data[GC0310_MAX_WRITE_BUF_SIZE];

};



struct gc0310_write_ctrl {

	int index;

	struct gc0310_write_buffer buffer;

};



/*

 * Register settings for various resolution

 */