linux-kernel - Re: [PATCH 3/3] phy: ti: j721e-wiz: Manage typec-gpio-dir

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Date:   Wed, 23 Oct 2019 11:10:49 +0300
From:   Roger Quadros <rogerq@...com>
To:     Jyri Sarha <jsarha@...com>, <kishon@...com>
CC:     <aniljoy@...ence.com>, <adouglas@...ence.com>, <nsekhar@...com>,
        <linux-kernel@...r.kernel.org>, <devicetree@...r.kernel.org>
Subject: Re: [PATCH 3/3] phy: ti: j721e-wiz: Manage typec-gpio-dir



On 23/10/2019 08:28, Jyri Sarha wrote:
> On 22/10/2019 16:22, Roger Quadros wrote:
>> Based on this GPIO state we need to configure LN10
>> bit to swap lane0 and lane1 if required (flipped connector).
>>
>> Type-C companions typically need some time after the cable is
>> plugged before and before they reflect the correct status of
>> Type-C plug orientation on the DIR line.
>>
>> Type-C Spec specifies CC attachment debounce time (tCCDebounce)
>> of 100 ms (min) to 200 ms (max).
>>
>> Use the DT property to figure out if we need to add delay
>> or not before sampling the Type-C DIR line.
>>
>> Signed-off-by: Roger Quadros <rogerq@...com>
>> Signed-off-by: Sekhar Nori <nsekhar@...com>
>> ---
>>   drivers/phy/ti/phy-j721e-wiz.c | 41 ++++++++++++++++++++++++++++++++++
>>   1 file changed, 41 insertions(+)
>>
>> diff --git a/drivers/phy/ti/phy-j721e-wiz.c b/drivers/phy/ti/phy-j721e-wiz.c
>> index 2a95da843e9f..2becdbcb762a 100644
>> --- a/drivers/phy/ti/phy-j721e-wiz.c
>> +++ b/drivers/phy/ti/phy-j721e-wiz.c
>> @@ -9,6 +9,8 @@
>>   #include <dt-bindings/phy/phy.h>
>>   #include <linux/clk.h>
>>   #include <linux/clk-provider.h>
>> +#include <linux/gpio.h>
>> +#include <linux/gpio/consumer.h>
>>   #include <linux/io.h>
>>   #include <linux/module.h>
>>   #include <linux/mux/consumer.h>
>> @@ -22,6 +24,7 @@
>>   #define WIZ_SERDES_CTRL		0x404
>>   #define WIZ_SERDES_TOP_CTRL	0x408
>>   #define WIZ_SERDES_RST		0x40c
>> +#define WIZ_SERDES_TYPEC	0x410
>>   #define WIZ_LANECTL(n)		(0x480 + (0x40 * (n)))
>>   
>>   #define WIZ_MAX_LANES		4
>> @@ -29,6 +32,8 @@
>>   #define WIZ_DIV_NUM_CLOCKS_16G	2
>>   #define WIZ_DIV_NUM_CLOCKS_10G	1
>>   
>> +#define WIZ_SERDES_TYPEC_LN10_SWAP	BIT(30)
>> +
>>   enum wiz_lane_standard_mode {
>>   	LANE_MODE_GEN1,
>>   	LANE_MODE_GEN2,
>> @@ -206,6 +211,8 @@ struct wiz {
>>   	u32			num_lanes;
>>   	struct platform_device	*serdes_pdev;
>>   	struct reset_controller_dev wiz_phy_reset_dev;
>> +	struct gpio_desc	*gpio_typec_dir;
>> +	int			typec_dir_delay;
>>   };
>>   
>>   static int wiz_reset(struct wiz *wiz)
>> @@ -703,6 +710,21 @@ static int wiz_phy_reset_deassert(struct reset_controller_dev *rcdev,
>>   	struct wiz *wiz = dev_get_drvdata(dev);
>>   	int ret;
>>   
>> +	/* if typec-dir gpio was specified, set LN10 SWAP bit based on that */
>> +	if (id == 0 && wiz->gpio_typec_dir) {
>> +		if (wiz->typec_dir_delay)
>> +			msleep_interruptible(wiz->typec_dir_delay);
>> +
>> +		if (gpiod_get_value_cansleep(wiz->gpio_typec_dir)) {
>> +			regmap_update_bits(wiz->regmap, WIZ_SERDES_TYPEC,
>> +					   WIZ_SERDES_TYPEC_LN10_SWAP,
>> +					   WIZ_SERDES_TYPEC_LN10_SWAP);
> 
> A nit pick, but wouldn't it be more coherent with the rest of the driver
> to define a REG_FIELD also for TYPEC_LN10_SWAP bit?

I agree. Although, I hate fields as you need to do so much boilerplate just to
flip one bit.

cheers,
-roger
> 
>> +		} else {
>> +			regmap_update_bits(wiz->regmap, WIZ_SERDES_TYPEC,
>> +					   WIZ_SERDES_TYPEC_LN10_SWAP, 0);
>> +		}
>> +	}
>> +
>>   	if (id == 0) {
>>   		ret = regmap_field_write(wiz->phy_reset_n, true);
>>   		return ret;
>> @@ -789,6 +811,25 @@ static int wiz_probe(struct platform_device *pdev)
>>   		goto err_addr_to_resource;
>>   	}
>>   
>> +	wiz->gpio_typec_dir = devm_gpiod_get_optional(dev, "typec-dir",
>> +						      GPIOD_IN);
>> +	if (IS_ERR(wiz->gpio_typec_dir)) {
>> +		ret = PTR_ERR(wiz->gpio_typec_dir);
>> +		if (ret != -EPROBE_DEFER)
>> +			dev_err(dev, "Failed to request typec-dir gpio: %d\n",
>> +				ret);
>> +		goto err_addr_to_resource;
>> +	}
>> +
>> +	if (wiz->gpio_typec_dir) {
>> +		ret = of_property_read_u32(node, "typec-dir-debounce",
>> +					   &wiz->typec_dir_delay);
>> +		if (ret && ret != -EINVAL) {
>> +			dev_err(dev, "Invalid typec-dir-debounce property\n");
>> +			goto err_addr_to_resource;
>> +		}
>> +	}
>> +
>>   	wiz->dev = dev;
>>   	wiz->regmap = regmap;
>>   	wiz->num_lanes = num_lanes;
>>
> 
> 

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