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SubjectRe: [PATCH 2/3] phy: ti-pipe3: i783 workaround for SATA lockup after dpll unlock/relock
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?

Thanks
Kishon


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