Re: [PATCH] phy: ti-pipe3: Add set_mode callback to configure usb3 phy as pcie phy

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+Rob,

On 30/01/19 15:00, Kishon Vijay Abraham I wrote:
> Hi Roger,
> 
> On 30/01/19 6:11 PM, Roger Quadros wrote:
>> Kishon,
>>
>> On 30/01/19 12:59, Kishon Vijay Abraham I wrote:
>>> Hi Roger,
>>>
>>> On 30/01/19 4:18 PM, Roger Quadros wrote:
>>>> Hi Kishon,
>>>>
>>>> On 24/01/19 12:48, Kishon Vijay Abraham I wrote:
>>>>> DRA72 platform has the second instance of PHY shared between USB3
>>>>> controller and PCIe controller with default as USB3 controller.
>>>>> Since it is used with USB3 controller by default, it uses the
>>>>> compatible specific to USB (ti,omap-usb3).
>>>>>
>>>>> Populate set_mode callback so that the USB3 PHY can be configured
>>>>> to be used with PCIe controller.
>>>>
>>>> What is the use case of this? At what point and who decides the
>>>> phy_set_mode() to be called with USB vs PCIe?
>>>
>>> The PHY by default is configured to be used with USB controller (That's why it
>>> has a compatible of ti,omap-usb3). However there is a special case where this
>>> PHY has to be used PCIe controller. So the set_mode() will help the PHY driver
>>> to configure the USB PHY to be used with PCIe controller.
>>>
>>> This is not a shared PHY, so the PHY as such can be used only with USB or PCIe
>>> and is determined at designtime
>>
>> If type is defined at design time then the design using the PHY for PCIe shouldn't be
>> using "ti,omap-usb3" compatible. Right?
> The second instance of PIPE3 PHY in dra72x SoC can be used either with USB3 or
> as a second lane of the 1st PCIe instance. How it is connected is based on
> board design. DRA72x EVM will need board modification for the PHY to be used
> with PCIe (by default it is connected to USB). AM571x IDK doesn't have a USB3
> port so the PIPE3 PHY is used with PCIe (USB2 also doesn't work with this
> configuration but that is a different HW issue).
> 
> I'm not sure if we should change the compatible in board dts file as it is
> based on board design. Previously I added a dt property to indicate the PHY
> should be configured for PCIe but Rob Herring suggested to use set_mode [1].

That is because you tried to add a new property "ti,configure-as-pcie" which
does seem unnecessary.

Wouldn't it work if you just use "ti,phy-pipe3-pcie" in the relevant device tree?

cheers,
-roger

> 
> Thanks
> Kishon
> 
> [1] -> https://lore.kernel.org/patchwork/patch/865398/
>>
>> Maybe we should fix the DT? Which board/PHY is this about?
>>
>> cheers,
>> -roger
>>
>>>>
>>>>
>>>>>
>>>>> Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx>
>>>>> ---
>>>>>  drivers/phy/ti/phy-ti-pipe3.c | 66 ++++++++++++++++++++++++++++-------
>>>>>  1 file changed, 54 insertions(+), 12 deletions(-)
>>>>>
>>>>> diff --git a/drivers/phy/ti/phy-ti-pipe3.c b/drivers/phy/ti/phy-ti-pipe3.c
>>>>> index 68ce4a082b9b..8c98f366416d 100644
>>>>> --- a/drivers/phy/ti/phy-ti-pipe3.c
>>>>> +++ b/drivers/phy/ti/phy-ti-pipe3.c
>>>>> @@ -56,6 +56,12 @@
>>>>>  
>>>>>  #define SATA_PLL_SOFT_RESET	BIT(18)
>>>>>  
>>>>> +#define PHY_RX_ANA_PRGRAMMABILITY_REG	0xC
>>>>> +#define MEM_EN_PLLBYP			BIT(7)
>>>>> +
>>>>> +#define PHY_TX_TEST_CONFIG		0x2C
>>>>> +#define MEM_ENTESTCLK			BIT(31)
>>>>> +
>>>>>  #define PIPE3_PHY_PWRCTL_CLK_CMD_MASK	0x003FC000
>>>>>  #define PIPE3_PHY_PWRCTL_CLK_CMD_SHIFT	14
>>>>>  
>>>>> @@ -110,6 +116,8 @@
>>>>>  #define PLL_IDLE_TIME	100	/* in milliseconds */
>>>>>  #define PLL_LOCK_TIME	100	/* in milliseconds */
>>>>>  
>>>>> +#define PIPE3_PHY_DISABLE_SYNC_POWER	BIT(4)
>>>>> +
>>>>>  struct pipe3_dpll_params {
>>>>>  	u16	m;
>>>>>  	u8	n;
>>>>> @@ -141,6 +149,7 @@ struct ti_pipe3 {
>>>>>  	unsigned int		power_reg; /* power reg. index within syscon */
>>>>>  	unsigned int		pcie_pcs_reg; /* pcs reg. index in syscon */
>>>>>  	bool			sata_refclk_enabled;
>>>>> +	u32			mode;
>>>>>  };
>>>>>  
>>>>>  static struct pipe3_dpll_map dpll_map_usb[] = {
>>>>> @@ -233,7 +242,10 @@ static int ti_pipe3_power_on(struct phy *x)
>>>>>  	rate = rate / 1000000;
>>>>>  	mask = OMAP_CTRL_PIPE3_PHY_PWRCTL_CLK_CMD_MASK |
>>>>>  		  OMAP_CTRL_PIPE3_PHY_PWRCTL_CLK_FREQ_MASK;
>>>>> -	val = PIPE3_PHY_TX_RX_POWERON << PIPE3_PHY_PWRCTL_CLK_CMD_SHIFT;
>>>>> +	val = PIPE3_PHY_TX_RX_POWERON;
>>>>> +	if (phy->mode == PHY_MODE_PCIE)
>>>>> +		val |= PIPE3_PHY_DISABLE_SYNC_POWER;
>>>>> +	val <<= PIPE3_PHY_PWRCTL_CLK_CMD_SHIFT;
>>>>>  	val |= rate << OMAP_CTRL_PIPE3_PHY_PWRCTL_CLK_FREQ_SHIFT;
>>>>>  
>>>>>  	ret = regmap_update_bits(phy->phy_power_syscon, phy->power_reg,
>>>>> @@ -328,13 +340,11 @@ static void ti_pipe3_calibrate(struct ti_pipe3 *phy)
>>>>>  	ti_pipe3_writel(phy->phy_rx, PCIEPHYRX_EQUALIZER, val);
>>>>>  }
>>>>>  
>>>>> -static int ti_pipe3_init(struct phy *x)
>>>>> +static int ti_pipe3_pcie_init(struct ti_pipe3 *phy)
>>>>>  {
>>>>> -	struct ti_pipe3 *phy = phy_get_drvdata(x);
>>>>> -	u32 val;
>>>>>  	int ret = 0;
>>>>> +	u32 val;
>>>>>  
>>>>> -	ti_pipe3_enable_clocks(phy);
>>>>>  	/*
>>>>>  	 * Set pcie_pcs register to 0x96 for proper functioning of phy
>>>>>  	 * as recommended in AM572x TRM SPRUHZ6, section 18.5.2.2, table
>>>>> @@ -353,10 +363,31 @@ static int ti_pipe3_init(struct phy *x)
>>>>>  			return ret;
>>>>>  
>>>>>  		ti_pipe3_calibrate(phy);
>>>>> -
>>>>> -		return 0;
>>>>> +	} else {
>>>>> +		val = ti_pipe3_readl(phy->phy_rx,
>>>>> +				     PHY_RX_ANA_PRGRAMMABILITY_REG);
>>>>> +		val |= MEM_EN_PLLBYP;
>>>>> +		ti_pipe3_writel(phy->phy_rx, PHY_RX_ANA_PRGRAMMABILITY_REG,
>>>>> +				val);
>>>>> +		val = ti_pipe3_readl(phy->phy_tx, PHY_TX_TEST_CONFIG);
>>>>> +		val |= MEM_ENTESTCLK;
>>>>> +		ti_pipe3_writel(phy->phy_tx, PHY_TX_TEST_CONFIG, val);
>>>>>  	}
>>>>>  
>>>>> +	return 0;
>>>>> +}
>>>>> +
>>>>> +static int ti_pipe3_init(struct phy *x)
>>>>> +{
>>>>> +	struct ti_pipe3 *phy = phy_get_drvdata(x);
>>>>> +	u32 val;
>>>>> +	int ret = 0;
>>>>> +
>>>>> +	ti_pipe3_enable_clocks(phy);
>>>>> +
>>>>> +	if (phy->mode == PHY_MODE_PCIE)
>>>>> +		return ti_pipe3_pcie_init(phy);
>>>>> +
>>>>>  	/* Bring it out of IDLE if it is IDLE */
>>>>>  	val = ti_pipe3_readl(phy->pll_ctrl_base, PLL_CONFIGURATION2);
>>>>>  	if (val & PLL_IDLE) {
>>>>> @@ -395,7 +426,7 @@ static int ti_pipe3_exit(struct phy *x)
>>>>>  		return 0;
>>>>>  
>>>>>  	/* PCIe doesn't have internal DPLL */
>>>>> -	if (!of_device_is_compatible(phy->dev->of_node, "ti,phy-pipe3-pcie")) {
>>>>> +	if (!(phy->mode == PHY_MODE_PCIE)) {
>>>>>  		/* Put DPLL in IDLE mode */
>>>>>  		val = ti_pipe3_readl(phy->pll_ctrl_base, PLL_CONFIGURATION2);
>>>>>  		val |= PLL_IDLE;
>>>>> @@ -429,11 +460,25 @@ static int ti_pipe3_exit(struct phy *x)
>>>>>  
>>>>>  	return 0;
>>>>>  }
>>>>> +
>>>>> +static int ti_pipe3_set_mode(struct phy *x, enum phy_mode mode, int submode)
>>>>> +{
>>>>> +	struct ti_pipe3 *phy = phy_get_drvdata(x);
>>>>> +
>>>>> +	if (phy->mode != PHY_MODE_INVALID)
>>>>> +		return -EBUSY;
>>>>> +
>>>>> +	phy->mode = mode;
>>>>
>>>> You are only saving the mode. But not really switching modes here.
>>>> How is this intended to work?
>>>
>>> The PHY doesn't have a specific mode. Rather it is a set of configurations
>>> required to operate in a particular mode.
>>>
>>> This mode value will be used in other init, power_on callback functions.
>>>
>>> Thanks
>>> Kishon
>>>
>>

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