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Message-ID: <66b1de88-dd11-178d-374b-09eb5739bfb3@ti.com>
Date: Thu, 31 Jan 2019 11:32:24 +0530
From: Kishon Vijay Abraham I <kishon@...com>
To: Roger Quadros <rogerq@...com>
CC: <linux-omap@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
Rob Herring <robh+dt@...nel.org>
Subject: Re: [PATCH] phy: ti-pipe3: Add set_mode callback to configure usb3
phy as pcie phy
Roger,
On 30/01/19 8:28 PM, Roger Quadros wrote:
> 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.
>
> How about rewording this to,
>
> "On DRA72x SoCs, the USB3 PHY can be used either as USB Super-Speed
> lane or as PCIe Lane (i.e. second lane for PCIe_SS1 in 2 lane mode or single
> lane for PCIe_SS2). The default mode for the USB3 PHY is USB Super-Speed.
> Provide a way for the PHY user to choose the appropriate mode via the
> .set_mode hook"
hmm okay
>
> More comments below.
>
>>
>> Signed-off-by: Kishon Vijay Abraham I <kishon@...com>
>> ---
>> 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;
>
> Is this required only for the USB3 PHY being used as PCIe lane or can it
> be done for the PCIe PHY as well?
This setting was given only for USB3 PHY. I did check PCIe PHY (1-lane) to see
if this is causing issues before posting the patch.
Thinking again, it might be safer to just use this setting for USB3 PHY.
>
> I ask this because phy->mode can be PHY_MODE_PCIE for both USB3 PHY and PCIe PHY
> and it might break PCIe PHY as we don't do PIPE3_PHY_DISABLE_SYNC_POWER for that
> currently.
>
> Maybe this is safer?
>
> if (phy->mode == PHY_MODE_PCIE && of_device_is_compatible(node, "ti,phy-usb3"))
yeah..
>
>> + 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 {
>
> How about
>
> else if (of_device_is_compatible(node, "ti,phy-usb3")) {
This check is implicit no?
> /* USB3 PHY being used as PCIe Lane */
>
>> + 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)
>
> Here you expect PHY "ti,phy-pipe3-pcie" to have mode = PHY_MODE_PCIE.
> Should we set the mode to PCI_MODE_PCIE explicitly it in probe?
The set_mode callback checks if the phy->mode is INVALID before setting the
mode. The phy_set_mode in the PCIe consumer driver will return error if it is
already set. The phy_set_mode will be called for both the lanes by the PCIe driver.
>
>> + 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)) {
>
> But this might be a USB3 PHY, which has DPLL.
hmm. I have to check this. We should also then reset PLL_IDLE bit in phy_init.
>
>> /* 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;
>
> We need to do a sanity check here and prevent unsupported modes being set.
>
> e.g. we don't want PCIe mode being set on omap-usb3 PHY or SATA PHY.
>
> Which makes me wonder, if all PHYs with compatible "ti,phy-usb3" don't support
> PCIe mode then we might need to add a new compatible for USB3 PHY's that do support
> PCIe mode?
>
> Or maybe a DT-property of supported PHY modes?
hmm yeah, makes sense.
>
>> +
>> + return 0;
>> +}
>> +
>> static const struct phy_ops ops = {
>> .init = ti_pipe3_init,
>> .exit = ti_pipe3_exit,
>> .power_on = ti_pipe3_power_on,
>> .power_off = ti_pipe3_power_off,
>> + .set_mode = ti_pipe3_set_mode,
>> .owner = THIS_MODULE,
>> };
>>
>> @@ -589,12 +634,8 @@ static int ti_pipe3_get_tx_rx_base(struct ti_pipe3 *phy)
>> {
>> struct resource *res;
>> struct device *dev = phy->dev;
>> - struct device_node *node = dev->of_node;
>> struct platform_device *pdev = to_platform_device(dev);
>>
>> - if (!of_device_is_compatible(node, "ti,phy-pipe3-pcie"))
>> - return 0;
>> -
>
> Do all USB3 and SATA PHYs have "phy_rx" and "phy_tx" regions?
> If not it will break them.
yes they have.
Thanks
Kishon
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