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

[Roger Quadros]

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?

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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