Re: [PATCH 3/8] drivers/mfd: Add lookup table for Panel Control as GPIO signal

Shobhit Kumar
2015-04-30T07:17:05Z

On 04/29/2015 07:57 PM, Lee Jones wrote:
> On Wed, 29 Apr 2015, Shobhit Kumar wrote:
>
>> On some Intel SoC platforms, the panel enable/disable signals are
>> controlled by CRC PMIC. Add those control as a new GPIO in a lookup
>> table for gpio-crystalcove chip during CRC driver load
>>
>> v2: Make the lookup table static (Thierry)
>> Remove the lookup table during driver remove (Thierry)
>>
>> CC: Samuel Ortiz <sameo@linux.intel.com>
>> Cc: Linus Walleij <linus.walleij@linaro.org>
>> Cc: Alexandre Courbot <gnurou@gmail.com>
>> Cc: Thierry Reding <thierry.reding@gmail.com>
>> Signed-off-by: Shobhit Kumar <shobhit.kumar@intel.com>
>> ---
>> drivers/mfd/intel_soc_pmic_core.c | 17 +++++++++++++++++
>> 1 file changed, 17 insertions(+)
>
> I have no idea what this stuff is, but it looks plausible.

The CRC PMIC controls the panel enable/disable signal using one of GPIO
like lines. It was agreed by Linus Walleij to go this way. The matching
crystalcove gpio changes are already merged in Linux next as -
http://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git/commit/?id=e189ca56d91bbf1d3fe2f88ab6858bf919d42adf

This just adds a consumer lookup table for the gpio. Since we do not
have a DT or board files, and since this was part of CRC driver, just
added the lookup table during CRC driver load itself. Same is done for
PWM in a later patch.

Regards
Shobhit

>
> For my own reference:
> Acked-by: Lee Jones <lee.jones@linaro.org>
>
>> diff --git a/drivers/mfd/intel_soc_pmic_core.c b/drivers/mfd/intel_soc_pmic_core.c
>> index 7b50b6b..f3d918e 100644
>> --- a/drivers/mfd/intel_soc_pmic_core.c
>> +++ b/drivers/mfd/intel_soc_pmic_core.c
>> @@ -24,8 +24,19 @@
>> #include <linux/acpi.h>
>> #include <linux/regmap.h>
>> #include <linux/mfd/intel_soc_pmic.h>
>> +#include <linux/gpio/machine.h>
>> #include "intel_soc_pmic_core.h"
>>
>> +/* Lookup table for the Panel Enable/Disable line as GPIO signals */
>> +static struct gpiod_lookup_table panel_gpio_table = {
>> + /* Intel GFX is consumer */
>> + .dev_id = "0000:00:02.0",
>> + .table = {
>> + /* Panel EN/DISABLE */
>> + GPIO_LOOKUP("gpio_crystalcove", 94, "panel", GPIO_ACTIVE_HIGH),
>> + },
>> +};
>> +
>> static int intel_soc_pmic_find_gpio_irq(struct device *dev)
>> {
>> struct gpio_desc *desc;
>> @@ -85,6 +96,9 @@ static int intel_soc_pmic_i2c_probe(struct i2c_client *i2c,
>> if (ret)
>> dev_warn(dev, "Can't enable IRQ as wake source: %d\n", ret);
>>
>> + /* Add lookup table binding for Panel Control to the GPIO Chip */
>> + gpiod_add_lookup_table(&panel_gpio_table);
>> +
>> ret = mfd_add_devices(dev, -1, config->cell_dev,
>> config->n_cell_devs, NULL, 0,
>> regmap_irq_get_domain(pmic->irq_chip_data));
>> @@ -104,6 +118,9 @@ static int intel_soc_pmic_i2c_remove(struct i2c_client *i2c)
>>
>> regmap_del_irq_chip(pmic->irq, pmic->irq_chip_data);
>>
>> + /* Remove lookup table for Panel Control from the GPIO Chip */
>> + gpiod_remove_lookup_table(&panel_gpio_table);
>> +
>> mfd_remove_devices(&i2c->dev);
>>
>> return 0;
>