Messages in this thread | | | Date | Tue, 26 May 2015 17:20:23 +0300 | From | Roger Quadros <> | Subject | Re: [PATCH 2/3] phy: ti-pipe3: i783 workaround for SATA lockup after dpll unlock/relock |
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Kishon,
On 23/05/15 10:22, Kishon Vijay Abraham I wrote: > Roger, > > On Friday 22 May 2015 07:28 PM, Roger Quadros wrote: >> Kishon, >> >> On 22/05/15 14:34, Kishon Vijay Abraham I wrote: >>> Roger, >>> >>> On Wednesday 20 May 2015 07:17 PM, Roger Quadros wrote: >>>> Kishon, >>>> >>>> On 20/05/15 16:19, Kishon Vijay Abraham I wrote: >>>>> Hi Roger, >>>>> >>>>> On Tuesday 12 May 2015 09:37 PM, Roger Quadros wrote: >>>>>> SATA_PLL_SOFT_RESET bit of CTRL_CORE_SMA_SW_0 must be toggled >>>>>> between a SATA DPLL unlock and re-lock to prevent SATA lockup. >>>>>> >>>>>> Introduce a new DT parameter 'syscon-pllreset' to provide the syscon >>>>>> regmap access to this register which sits in the control module. >>>>>> >>>>>> If the register is not provided we fallback to the old behaviour >>>>>> i.e. SATA DPLL refclk will not be disabled and we prevent SoC low >>>>>> power states. >>>>>> >>>>>> Signed-off-by: Roger Quadros <rogerq@ti.com> >>>>>> --- >>>>>> Documentation/devicetree/bindings/phy/ti-phy.txt | 16 ++++++ >>>>>> drivers/phy/phy-ti-pipe3.c | 67 >>>>>> ++++++++++++++++++++---- >>>>>> 2 files changed, 74 insertions(+), 9 deletions(-) >>>>>> >>>>>> diff --git a/Documentation/devicetree/bindings/phy/ti-phy.txt >>>>>> b/Documentation/devicetree/bindings/phy/ti-phy.txt >>>>>> index 305e3df..f0f5537 100644 >>>>>> --- a/Documentation/devicetree/bindings/phy/ti-phy.txt >>>>>> +++ b/Documentation/devicetree/bindings/phy/ti-phy.txt >>>>>> @@ -82,6 +82,9 @@ Optional properties: >>>>>> - id: If there are multiple instance of the same type, in order to >>>>>> differentiate between each instance "id" can be used (e.g., >>>>>> multi-lane PCIe >>>>>> PHY). If "id" is not provided, it is set to default value of '1'. >>>>>> + - syscon-pllreset: Handle to system control region that contains the >>>>>> + CTRL_CORE_SMA_SW_0 register and register offset to the >>>>>> CTRL_CORE_SMA_SW_0 >>>>>> + register that contains the SATA_PLL_SOFT_RESET bit. Only valid for >>>>>> sata_phy. >>>>>> >>>>>> This is usually a subnode of ocp2scp to which it is connected. >>>>>> >>>>>> @@ -100,3 +103,16 @@ usb3phy@4a084400 { >>>>>> "sysclk", >>>>>> "refclk"; >>>>>> }; >>>>>> + >>>>>> +sata_phy: phy@4A096000 { >>>>>> + compatible = "ti,phy-pipe3-sata"; >>>>>> + reg = <0x4A096000 0x80>, /* phy_rx */ >>>>>> + <0x4A096400 0x64>, /* phy_tx */ >>>>>> + <0x4A096800 0x40>; /* pll_ctrl */ >>>>>> + reg-names = "phy_rx", "phy_tx", "pll_ctrl"; >>>>>> + ctrl-module = <&omap_control_sata>; >>>>>> + clocks = <&sys_clkin1>, <&sata_ref_clk>; >>>>>> + clock-names = "sysclk", "refclk"; >>>>>> + syscon-pllreset = <&dra7_ctrl_core 0x3fc>; >>>>>> + #phy-cells = <0>; >>>>>> +}; >>>>>> diff --git a/drivers/phy/phy-ti-pipe3.c b/drivers/phy/phy-ti-pipe3.c >>>>>> index e13a306..d730142 100644 >>>>>> --- a/drivers/phy/phy-ti-pipe3.c >>>>>> +++ b/drivers/phy/phy-ti-pipe3.c >>>>>> @@ -28,6 +28,8 @@ >>>>>> #include <linux/delay.h> >>>>>> #include <linux/phy/omap_control_phy.h> >>>>>> #include <linux/of_platform.h> >>>>>> +#include <linux/mfd/syscon.h> >>>>>> +#include <linux/regmap.h> >>>>>> >>>>>> #define PLL_STATUS 0x00000004 >>>>>> #define PLL_GO 0x00000008 >>>>>> @@ -52,6 +54,8 @@ >>>>>> #define PLL_LOCK 0x2 >>>>>> #define PLL_IDLE 0x1 >>>>>> >>>>>> +#define SATA_PLL_SOFT_RESET BIT(18) >>>>>> + >>>>>> /* >>>>>> * This is an Empirical value that works, need to confirm the actual >>>>>> * value required for the PIPE3PHY_PLL_CONFIGURATION2.PLL_IDLE status >>>>>> @@ -82,6 +86,9 @@ struct ti_pipe3 { >>>>>> struct clk *refclk; >>>>>> struct clk *div_clk; >>>>>> struct pipe3_dpll_map *dpll_map; >>>>>> + struct regmap *dpll_reset_syscon; /* ctrl. reg. acces */ >>>>>> + unsigned int dpll_reset_reg; /* reg. index within syscon */ >>>>>> + bool sata_refclk_enabled; >>>>>> }; >>>>>> >>>>>> static struct pipe3_dpll_map dpll_map_usb[] = { >>>>>> @@ -249,11 +256,15 @@ static int ti_pipe3_exit(struct phy *x) >>>>>> u32 val; >>>>>> unsigned long timeout; >>>>>> >>>>>> - /* SATA DPLL can't be powered down due to Errata i783 and PCIe >>>>>> - * does not have internal DPLL >>>>>> + /* If dpll_reset_syscon is not present we wont power down SATA DPLL >>>>>> + * due to Errata i783 >>>>>> */ >>>>>> - if (of_device_is_compatible(phy->dev->of_node, >>>>>> "ti,phy-pipe3-sata") || >>>>>> - of_device_is_compatible(phy->dev->of_node, "ti,phy-pipe3-pcie")) >>>>>> + if (of_device_is_compatible(phy->dev->of_node, >>>>>> "ti,phy-pipe3-sata") && >>>>>> + !phy->dpll_reset_syscon) >>>>>> + return 0; >>>>>> + >>>>>> + /* PCIe doesn't have DPLL. FIXME: need to disable clocks though */ >>>>> >>>>> I think it's better to fix it in this patch itself.. to disable clocks >>>>> for PCIe. >>>>>> + if (of_device_is_compatible(phy->dev->of_node, "ti,phy-pipe3-pcie")) >>>>>> return 0; >>>>>> >>>>>> /* Put DPLL in IDLE mode */ >>>>>> @@ -276,6 +287,14 @@ static int ti_pipe3_exit(struct phy *x) >>>>>> return -EBUSY; >>>>>> } >>>>>> >>>>>> + /* i783: SATA needs control bit toggle after PLL unlock */ >>>>>> + if (of_device_is_compatible(phy->dev->of_node, >>>>>> "ti,phy-pipe3-sata")) { >>>>>> + regmap_update_bits(phy->dpll_reset_syscon, phy->dpll_reset_reg, >>>>>> + SATA_PLL_SOFT_RESET, SATA_PLL_SOFT_RESET); >>>>>> + regmap_update_bits(phy->dpll_reset_syscon, phy->dpll_reset_reg, >>>>>> + SATA_PLL_SOFT_RESET, 0); >>>>>> + } >>>>>> + >>>>>> ti_pipe3_disable_clocks(phy); >>>>>> >>>>>> return 0; >>>>>> @@ -350,6 +369,21 @@ static int ti_pipe3_probe(struct platform_device >>>>>> *pdev) >>>>>> } >>>>>> } else { >>>>>> phy->wkupclk = ERR_PTR(-ENODEV); >>>>>> + phy->dpll_reset_syscon = syscon_regmap_lookup_by_phandle(node, >>>>>> + "syscon-pllreset"); >>>>>> + if (IS_ERR(phy->dpll_reset_syscon)) { >>>>>> + dev_info(&pdev->dev, >>>>>> + "can't get syscon-pllreset, sata dpll won't idle\n"); >>>>>> + phy->dpll_reset_syscon = NULL; >>>>>> + } else { >>>>>> + if (of_property_read_u32_index(node, >>>>>> + "syscon-pllreset", 1, >>>>>> + &phy->dpll_reset_reg)) { >>>>>> + dev_err(&pdev->dev, >>>>>> + "couldn't get pllreset reg. offset\n"); >>>>>> + return -EINVAL; >>>>>> + } >>>>>> + } >>>>>> } >>>>>> >>>>>> if (of_device_is_compatible(node, "ti,phy-pipe3-pcie")) { >>>>>> @@ -402,9 +436,16 @@ static int ti_pipe3_probe(struct platform_device >>>>>> *pdev) >>>>>> >>>>>> platform_set_drvdata(pdev, phy); >>>>>> pm_runtime_enable(phy->dev); >>>>>> - /* Prevent auto-disable of refclk for SATA PHY due to Errata i783 */ >>>>>> - if (of_device_is_compatible(node, "ti,phy-pipe3-sata")) >>>>>> - clk_prepare_enable(phy->refclk); >>>>>> + >>>>>> + /* >>>>>> + * Prevent auto-disable of refclk for SATA PHY due to Errata i783 >>>>>> + */ >>>>>> + if (of_device_is_compatible(node, "ti,phy-pipe3-sata")) { >>>>>> + if (!IS_ERR(phy->refclk)) { >>>>>> + clk_prepare_enable(phy->refclk); >>>>>> + phy->sata_refclk_enabled = true; >>>>>> + } >>>>>> + } >>>>>> >>>>>> generic_phy = devm_phy_create(phy->dev, NULL, &ops); >>>>>> if (IS_ERR(generic_phy)) >>>>>> @@ -443,8 +484,17 @@ static int ti_pipe3_enable_refclk(struct ti_pipe3 >>>>>> *phy) >>>>>> >>>>>> static void ti_pipe3_disable_refclk(struct ti_pipe3 *phy) >>>>>> { >>>>>> - if (!IS_ERR(phy->refclk)) >>>>>> + if (!IS_ERR(phy->refclk)) { >>>>>> clk_disable_unprepare(phy->refclk); >>>>>> + /* >>>>>> + * SATA refclk needs an additional disable as we left it >>>>>> + * on in probe to avoid Errata i783 >>>>> >>>>> not sure I get this. Why don't we remove it in probe? >>>> >>>> Because if we remove it from probe and if AHCI_PLATFORM is built as a >>>> module then phy_init won't be called before kernel starts autodisabling >>>> unused clocks and so SATA refclk gets disabled causing i783 and >>>> breaking SATA. >>> >>> Just to be clear, this entire thing won't be required if uboot does SATA_PLL_SOFT_RESET no? >>> >> >> Yes that is right. We don't yet have the u-boot fix and there is no guarantee all users move >> to the u-boot with the fix, so this is important. > > Okay. Just thinking if we can do SATA_PLL_SOFT_RESET in probe to begin with. That way we don't have to do this additional clk_enable(). >
I had tried it but it didn't work.
cheers, -roger
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