Hi Jacopo,
On 02/11/2018 11:04, jacopo mondi wrote:
> Hi Niklas,
>
> On Fri, Nov 02, 2018 at 11:44:25AM +0100, Niklas Söderlund wrote:
>> Hi Jacopo,
>>
>> Thanks for your feedback.
>>
>> On 2018-10-05 12:46:15 +0200, Jacopo Mondi wrote:
>>> Hi Niklas,
>>>
>>> On Thu, Oct 04, 2018 at 10:41:38PM +0200, Niklas Söderlund wrote:
>>>> From: Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>
>>>>
>>>> The driver fixed the TXA CSI-2 transmitter in 4-lane mode while it could
>>>> operate using 1-, 2- and 4-lanes. Update the driver to support all modes
>>>> the hardware does.
>>>>
>>>> The driver make use of large tables of static register/value writes when
>>>> powering up/down the TXA and TXB transmitters which include the write to
>>>> the NUM_LANES register. By converting the tables into functions and
>>>> using parameters the power up/down functions for TXA and TXB power
>>>> up/down can be merged and used for both transmitters.
>>>>
>>>> Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>
>>>>
>>>> ---
>>>> * Changes since v1
>>>> - Convert tables of register/value writes into functions instead of
>>>> intercepting and modifying the writes to the NUM_LANES register.
>>>> ---
>>>> drivers/media/i2c/adv748x/adv748x-core.c | 132 ++++++++++++-----------
>>>> 1 file changed, 67 insertions(+), 65 deletions(-)
>>>>
>>>> diff --git a/drivers/media/i2c/adv748x/adv748x-core.c b/drivers/media/i2c/adv748x/adv748x-core.c
>>>> index 3836dd3025d6ffb7..fe29781368a3a6b6 100644
>>>> --- a/drivers/media/i2c/adv748x/adv748x-core.c
>>>> +++ b/drivers/media/i2c/adv748x/adv748x-core.c
>>>> @@ -125,6 +125,16 @@ int adv748x_write(struct adv748x_state *state, u8 page, u8 reg, u8 value)
>>>> return regmap_write(state->regmap[page], reg, value);
>>>> }
>>>>
>>>> +static int adv748x_write_check(struct adv748x_state *state, u8 page, u8 reg,
>>>> + u8 value, int *error)
>>>
>>> Am I wrong or the return error is ignored and could be dropped?
>>
>> No it's used to reduce boiler plate code, see adv748x_power_up_tx()
>> bellow for one example.
>
> I meant the function return value. It is never checked:
>
> adv748x_write_check(state, page, 0x31, 0x82, &ret);
I would vote to keep the return value - even if in most cases it's unused.
It will allow for the last statement in a function to be :
{
...
return adv748x_write_check(state, page, 0x1e, 0x40, &ret);
}
Which might be desirable in some cases.
I'll bet the compiler will optimise the value out if it's not used anyway.
--
Kieran
>
>>
>> int ret = 0;
>> ...
>> adv748x_write_check(state, page, 0x31, 0x82, &ret);
>> adv748x_write_check(state, page, 0x1e, 0x40, &ret);
>> ...
>> return ret;
>>
>> If the first adv748x_write_check() fails all later calls to
>> adv748x_write_check() will do nothing. This is do avoid the rather hard
>> to read:
>>
>> ret = adv748x_write(state, page, 0x31, 0x82);
>> if (ret)
>> return ret;
>>
>> ret = adv748x_write(state, page, 0x1e, 0x40);
>> if (ret)
>> return ret;
>>
>>>
>>>> +{
>>>> + if (*error)
>>>> + return *error;
>>>> +
>>>> + *error = adv748x_write(state, page, reg, value);
>>>> + return *error;
>>>> +}
>>>> +
>>>> /* adv748x_write_block(): Write raw data with a maximum of I2C_SMBUS_BLOCK_MAX
>>>> * size to one or more registers.
>>>> *
>>>> @@ -231,69 +241,63 @@ static int adv748x_write_regs(struct adv748x_state *state,
>>>> * TXA and TXB
>>>> */
>>>>
>>>> -static const struct adv748x_reg_value adv748x_power_up_txa_4lane[] = {
>>>> -
>>>> - {ADV748X_PAGE_TXA, 0x00, 0x84}, /* Enable 4-lane MIPI */
>>>> - {ADV748X_PAGE_TXA, 0x00, 0xa4}, /* Set Auto DPHY Timing */
>>>> -
>>>> - {ADV748X_PAGE_TXA, 0x31, 0x82}, /* ADI Required Write */
>>>> - {ADV748X_PAGE_TXA, 0x1e, 0x40}, /* ADI Required Write */
>>>> - {ADV748X_PAGE_TXA, 0xda, 0x01}, /* i2c_mipi_pll_en - 1'b1 */
>>>> - {ADV748X_PAGE_WAIT, 0x00, 0x02},/* delay 2 */
>>>> - {ADV748X_PAGE_TXA, 0x00, 0x24 },/* Power-up CSI-TX */
>>>> - {ADV748X_PAGE_WAIT, 0x00, 0x01},/* delay 1 */
>>>> - {ADV748X_PAGE_TXA, 0xc1, 0x2b}, /* ADI Required Write */
>>>> - {ADV748X_PAGE_WAIT, 0x00, 0x01},/* delay 1 */
>>>> - {ADV748X_PAGE_TXA, 0x31, 0x80}, /* ADI Required Write */
>>>> -
>>>> - {ADV748X_PAGE_EOR, 0xff, 0xff} /* End of register table */
>>>> -};
>>>> -
>>>> -static const struct adv748x_reg_value adv748x_power_down_txa_4lane[] = {
>>>> -
>>>> - {ADV748X_PAGE_TXA, 0x31, 0x82}, /* ADI Required Write */
>>>> - {ADV748X_PAGE_TXA, 0x1e, 0x00}, /* ADI Required Write */
>>>> - {ADV748X_PAGE_TXA, 0x00, 0x84}, /* Enable 4-lane MIPI */
>>>> - {ADV748X_PAGE_TXA, 0xda, 0x01}, /* i2c_mipi_pll_en - 1'b1 */
>>>> - {ADV748X_PAGE_TXA, 0xc1, 0x3b}, /* ADI Required Write */
>>>> -
>>>> - {ADV748X_PAGE_EOR, 0xff, 0xff} /* End of register table */
>>>> -};
>>>> -
>>>> -static const struct adv748x_reg_value adv748x_power_up_txb_1lane[] = {
>>>> -
>>>> - {ADV748X_PAGE_TXB, 0x00, 0x81}, /* Enable 1-lane MIPI */
>>>> - {ADV748X_PAGE_TXB, 0x00, 0xa1}, /* Set Auto DPHY Timing */
>>>> -
>>>> - {ADV748X_PAGE_TXB, 0x31, 0x82}, /* ADI Required Write */
>>>> - {ADV748X_PAGE_TXB, 0x1e, 0x40}, /* ADI Required Write */
>>>> - {ADV748X_PAGE_TXB, 0xda, 0x01}, /* i2c_mipi_pll_en - 1'b1 */
>>>> - {ADV748X_PAGE_WAIT, 0x00, 0x02},/* delay 2 */
>>>> - {ADV748X_PAGE_TXB, 0x00, 0x21 },/* Power-up CSI-TX */
>>>> - {ADV748X_PAGE_WAIT, 0x00, 0x01},/* delay 1 */
>>>> - {ADV748X_PAGE_TXB, 0xc1, 0x2b}, /* ADI Required Write */
>>>> - {ADV748X_PAGE_WAIT, 0x00, 0x01},/* delay 1 */
>>>> - {ADV748X_PAGE_TXB, 0x31, 0x80}, /* ADI Required Write */
>>>> -
>>>> - {ADV748X_PAGE_EOR, 0xff, 0xff} /* End of register table */
>>>> -};
>>>> -
>>>> -static const struct adv748x_reg_value adv748x_power_down_txb_1lane[] = {
>>>> -
>>>> - {ADV748X_PAGE_TXB, 0x31, 0x82}, /* ADI Required Write */
>>>> - {ADV748X_PAGE_TXB, 0x1e, 0x00}, /* ADI Required Write */
>>>> - {ADV748X_PAGE_TXB, 0x00, 0x81}, /* Enable 1-lane MIPI */
>>>> - {ADV748X_PAGE_TXB, 0xda, 0x01}, /* i2c_mipi_pll_en - 1'b1 */
>>>> - {ADV748X_PAGE_TXB, 0xc1, 0x3b}, /* ADI Required Write */
>>>> -
>>>> - {ADV748X_PAGE_EOR, 0xff, 0xff} /* End of register table */
>>>> -};
>>>> +static int adv748x_power_up_tx(struct adv748x_csi2 *tx)
>>>> +{
>>>> + struct adv748x_state *state = tx->state;
>>>> + u8 page = is_txa(tx) ? ADV748X_PAGE_TXA : ADV748X_PAGE_TXB;
>>>> + int ret = 0;
>>>> +
>>>> + /* Enable 4-lane MIPI */
>>>> + adv748x_write_check(state, page, 0x00, 0x80 | tx->num_lanes, &ret);
>>>> +
>>>> + /* Set Auto DPHY Timing */
>>>> + adv748x_write_check(state, page, 0x00, 0xa0 | tx->num_lanes, &ret);
>>>> +
>>>> + /* ADI Required Writes*/
>>>> + adv748x_write_check(state, page, 0x31, 0x82, &ret);
>>>> + adv748x_write_check(state, page, 0x1e, 0x40, &ret);
>>>> +
>>>> + /* i2c_mipi_pll_en - 1'b1 */
>>>> + adv748x_write_check(state, page, 0xda, 0x01, &ret);
>>>> + usleep_range(2000, 2500);
>>>> +
>>>> + /* Power-up CSI-TX */
>>>> + adv748x_write_check(state, page, 0x00, 0x20 | tx->num_lanes, &ret);
>>>> + usleep_range(1000, 1500);
>>>> +
>>>> + /* ADI Required Writes*/
>>>> + adv748x_write_check(state, page, 0xc1, 0x2b, &ret);
>>>> + usleep_range(1000, 1500);
>>>> + adv748x_write_check(state, page, 0x31, 0x80, &ret);
>>>> +
>>>> + return ret;
>>>> +}
>>>> +
>>>> +static int adv748x_power_down_tx(struct adv748x_csi2 *tx)
>>>> +{
>>>> + struct adv748x_state *state = tx->state;
>>>> + u8 page = is_txa(tx) ? ADV748X_PAGE_TXA : ADV748X_PAGE_TXB;
>>>> + int ret = 0;
>>>> +
>>>> + /* ADI Required Writes */
>>>> + adv748x_write_check(state, page, 0x31, 0x82, &ret);
>>>> + adv748x_write_check(state, page, 0x1e, 0x00, &ret);
>>>> +
>>>> + /* Enable 4-lane MIPI */
>>>> + adv748x_write_check(state, page, 0x00, 0x80 | tx->num_lanes, &ret);
>>>> +
>>>> + /* i2c_mipi_pll_en - 1'b1 */
>>>> + adv748x_write_check(state, page, 0xda, 0x01, &ret);
>>>> +
>>>> + /* ADI Required Write */
>>>> + adv748x_write_check(state, page, 0xc1, 0x3b, &ret);
>>>> +
>>>> + return ret;
>>>> +}
>>>
>>> This one looks good to me
>>>
>>>>
>>>> int adv748x_tx_power(struct adv748x_csi2 *tx, bool on)
>>>> {
>>>> - struct adv748x_state *state = tx->state;
>>>> - const struct adv748x_reg_value *reglist;
>>>> - int val;
>>>> + int val, ret;
>>>>
>>>> if (!is_tx_enabled(tx))
>>>> return 0;
>>>> @@ -311,13 +315,11 @@ int adv748x_tx_power(struct adv748x_csi2 *tx, bool on)
>>>> "Enabling with unknown bit set");
>>>>
>>>> if (on)
>>>> - reglist = is_txa(tx) ? adv748x_power_up_txa_4lane :
>>>> - adv748x_power_up_txb_1lane;
>>>> + ret = adv748x_power_up_tx(tx);
>>>> else
>>>> - reglist = is_txa(tx) ? adv748x_power_down_txa_4lane :
>>>> - adv748x_power_down_txb_1lane;
>>>> + ret = adv748x_power_down_tx(tx);
>>>>
>>>> - return adv748x_write_regs(state, reglist);
>>>> + return ret;
>>>
>>> As Laurent suggested, or even
>>> return on ? adv748x_power_up_tx(tx) : adv748x_power_down_tx(tx);
>>
>> Good idea!
>>
>>>
>>> Thanks
>>> j
>>>
>>>> }
>>>>
>>>> /* -----------------------------------------------------------------------------
>>>> --
>>>> 2.19.0
>>>>
>>
>>
>>
>> --
>> Regards,
>> Niklas Söderlund
--
Regards
--
Kieran
