On Wed, Apr 20, 2016 at 08:45:29AM -0700, Andrey Smirnov wrote:
> Use enumerated type instead of a boolean flag to specify the variant of
> the PCIe IP block (6Q, 6SX, etc). This patch has zero functional impact,
> however it makes the code easier to extend for the case of more than 2
> possible variants of an IP block (of which there are).
> 
> Signed-off-by: Andrey Smirnov <andrew.smir...@gmail.com>

Applied with Fabio's Reviewed-by and Gary's Tested-by to pci/host-imx6
for v4.7, thanks, Andrey!  Also, thank you Fabio, Gary, and Lucas for
reviewing and testing.

> ---
> 
> Changes since v2:
>       - Removed default clause in all introduced switch statements
>       - Switched to using of_device_get_match_data instead of
>           explicit of_device_is_compatible checks
>       - Added a mention of the new DT compatibility string in the 
> documentation
> 
> Changes since v1:
> 
>       - Patchset is rebased against
>           
> https://git.kernel.org/cgit/linux/kernel/git/helgaas/pci.git/log/?h=pci/host-imx6
> 
>       - DTS files changes moved into a separate patch
> 
>  drivers/pci/host/pci-imx6.c | 124 
> ++++++++++++++++++++++++--------------------
>  1 file changed, 67 insertions(+), 57 deletions(-)
> 
> diff --git a/drivers/pci/host/pci-imx6.c b/drivers/pci/host/pci-imx6.c
> index 0f6d630..a77e7fd 100644
> --- a/drivers/pci/host/pci-imx6.c
> +++ b/drivers/pci/host/pci-imx6.c
> @@ -19,6 +19,7 @@
>  #include <linux/mfd/syscon/imx6q-iomuxc-gpr.h>
>  #include <linux/module.h>
>  #include <linux/of_gpio.h>
> +#include <linux/of_device.h>
>  #include <linux/pci.h>
>  #include <linux/platform_device.h>
>  #include <linux/regmap.h>
> @@ -31,6 +32,11 @@
>  
>  #define to_imx6_pcie(x)      container_of(x, struct imx6_pcie, pp)
>  
> +enum imx6_pcie_variants {
> +     IMX6Q,
> +     IMX6SX
> +};
> +
>  struct imx6_pcie {
>       struct gpio_desc        *reset_gpio;
>       struct clk              *pcie_bus;
> @@ -39,7 +45,7 @@ struct imx6_pcie {
>       struct clk              *pcie;
>       struct pcie_port        pp;
>       struct regmap           *iomuxc_gpr;
> -     bool                    is_imx6sx;
> +     enum imx6_pcie_variants variant;
>       void __iomem            *mem_base;
>       u32                     tx_deemph_gen1;
>       u32                     tx_deemph_gen2_3p5db;
> @@ -238,7 +244,8 @@ static int imx6_pcie_assert_core_reset(struct pcie_port 
> *pp)
>       struct imx6_pcie *imx6_pcie = to_imx6_pcie(pp);
>       u32 val, gpr1, gpr12;
>  
> -     if (imx6_pcie->is_imx6sx) {
> +     switch (imx6_pcie->variant) {
> +     case IMX6SX:
>               regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
>                                  IMX6SX_GPR12_PCIE_TEST_POWERDOWN,
>                                  IMX6SX_GPR12_PCIE_TEST_POWERDOWN);
> @@ -246,72 +253,76 @@ static int imx6_pcie_assert_core_reset(struct pcie_port 
> *pp)
>               regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR5,
>                                  IMX6SX_GPR5_PCIE_BTNRST_RESET,
>                                  IMX6SX_GPR5_PCIE_BTNRST_RESET);
> -             return 0;
> -     }
> -
> -     /*
> -      * If the bootloader already enabled the link we need some special
> -      * handling to get the core back into a state where it is safe to
> -      * touch it for configuration.  As there is no dedicated reset signal
> -      * wired up for MX6QDL, we need to manually force LTSSM into "detect"
> -      * state before completely disabling LTSSM, which is a prerequisite
> -      * for core configuration.
> -      *
> -      * If both LTSSM_ENABLE and REF_SSP_ENABLE are active we have a strong
> -      * indication that the bootloader activated the link.
> -      */
> -     regmap_read(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, &gpr1);
> -     regmap_read(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, &gpr12);
> -
> -     if ((gpr1 & IMX6Q_GPR1_PCIE_REF_CLK_EN) &&
> -         (gpr12 & IMX6Q_GPR12_PCIE_CTL_2)) {
> -             val = readl(pp->dbi_base + PCIE_PL_PFLR);
> -             val &= ~PCIE_PL_PFLR_LINK_STATE_MASK;
> -             val |= PCIE_PL_PFLR_FORCE_LINK;
> -             writel(val, pp->dbi_base + PCIE_PL_PFLR);
> +             break;
> +     case IMX6Q:
> +             /*
> +              * If the bootloader already enabled the link we need some 
> special
> +              * handling to get the core back into a state where it is safe 
> to
> +              * touch it for configuration.  As there is no dedicated reset 
> signal
> +              * wired up for MX6QDL, we need to manually force LTSSM into 
> "detect"
> +              * state before completely disabling LTSSM, which is a 
> prerequisite
> +              * for core configuration.
> +              *
> +              * If both LTSSM_ENABLE and REF_SSP_ENABLE are active we have a 
> strong
> +              * indication that the bootloader activated the link.
> +              */
> +             regmap_read(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, &gpr1);
> +             regmap_read(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, &gpr12);
> +
> +             if ((gpr1 & IMX6Q_GPR1_PCIE_REF_CLK_EN) &&
> +                 (gpr12 & IMX6Q_GPR12_PCIE_CTL_2)) {
> +                     val = readl(pp->dbi_base + PCIE_PL_PFLR);
> +                     val &= ~PCIE_PL_PFLR_LINK_STATE_MASK;
> +                     val |= PCIE_PL_PFLR_FORCE_LINK;
> +                     writel(val, pp->dbi_base + PCIE_PL_PFLR);
> +
> +                     regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
> +                                        IMX6Q_GPR12_PCIE_CTL_2, 0 << 10);
> +             }
>  
> -             regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
> -                             IMX6Q_GPR12_PCIE_CTL_2, 0 << 10);
> +             regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
> +                                IMX6Q_GPR1_PCIE_TEST_PD, 1 << 18);
> +             regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
> +                                IMX6Q_GPR1_PCIE_REF_CLK_EN, 0 << 16);
> +             break;
>       }
>  
> -     regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
> -                     IMX6Q_GPR1_PCIE_TEST_PD, 1 << 18);
> -     regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
> -                     IMX6Q_GPR1_PCIE_REF_CLK_EN, 0 << 16);
> -
>       return 0;
>  }
>  
>  static int imx6_pcie_enable_ref_clk(struct imx6_pcie *imx6_pcie)
>  {
>       struct pcie_port *pp = &imx6_pcie->pp;
> -     int ret;
> +     int ret = 0;
>  
> -     if (imx6_pcie->is_imx6sx) {
> +     switch (imx6_pcie->variant) {
> +     case IMX6SX:
>               ret = clk_prepare_enable(imx6_pcie->pcie_inbound_axi);
>               if (ret) {
>                       dev_err(pp->dev, "unable to enable pcie_axi clock\n");
> -                     return ret;
> +                     break;
>               }
>  
>               regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
>                                  IMX6SX_GPR12_PCIE_TEST_POWERDOWN, 0);
> -             return ret;
> +             break;
> +     case IMX6Q:
> +             /* power up core phy and enable ref clock */
> +             regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
> +                                IMX6Q_GPR1_PCIE_TEST_PD, 0 << 18);
> +             /*
> +              * the async reset input need ref clock to sync internally,
> +              * when the ref clock comes after reset, internal synced
> +              * reset time is too short, cannot meet the requirement.
> +              * add one ~10us delay here.
> +              */
> +             udelay(10);
> +             regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
> +                                IMX6Q_GPR1_PCIE_REF_CLK_EN, 1 << 16);
> +             break;
>       }
>  
> -     /* power up core phy and enable ref clock */
> -     regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
> -                     IMX6Q_GPR1_PCIE_TEST_PD, 0 << 18);
> -     /*
> -      * the async reset input need ref clock to sync internally,
> -      * when the ref clock comes after reset, internal synced
> -      * reset time is too short, cannot meet the requirement.
> -      * add one ~10us delay here.
> -      */
> -     udelay(10);
> -     regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
> -                     IMX6Q_GPR1_PCIE_REF_CLK_EN, 1 << 16);
> -     return 0;
> +     return ret;
>  }
>  
>  static int imx6_pcie_deassert_core_reset(struct pcie_port *pp)
> @@ -353,7 +364,7 @@ static int imx6_pcie_deassert_core_reset(struct pcie_port 
> *pp)
>               gpiod_set_value_cansleep(imx6_pcie->reset_gpio, 1);
>       }
>  
> -     if (imx6_pcie->is_imx6sx)
> +     if (imx6_pcie->variant == IMX6SX)
>               regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR5,
>                                  IMX6SX_GPR5_PCIE_BTNRST_RESET, 0);
>  
> @@ -374,11 +385,10 @@ static void imx6_pcie_init_phy(struct pcie_port *pp)
>  {
>       struct imx6_pcie *imx6_pcie = to_imx6_pcie(pp);
>  
> -     if (imx6_pcie->is_imx6sx) {
> +     if (imx6_pcie->variant == IMX6SX)
>               regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
>                                  IMX6SX_GPR12_PCIE_RX_EQ_MASK,
>                                  IMX6SX_GPR12_PCIE_RX_EQ_2);
> -     }
>  
>       regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
>                       IMX6Q_GPR12_PCIE_CTL_2, 0 << 10);
> @@ -585,8 +595,8 @@ static int __init imx6_pcie_probe(struct platform_device 
> *pdev)
>       pp = &imx6_pcie->pp;
>       pp->dev = &pdev->dev;
>  
> -     imx6_pcie->is_imx6sx = of_device_is_compatible(pp->dev->of_node,
> -                                                    "fsl,imx6sx-pcie");
> +     imx6_pcie->variant =
> +             (enum imx6_pcie_variants)of_device_get_match_data(&pdev->dev);
>  
>       /* Added for PCI abort handling */
>       hook_fault_code(16 + 6, imx6q_pcie_abort_handler, SIGBUS, 0,
> @@ -623,7 +633,7 @@ static int __init imx6_pcie_probe(struct platform_device 
> *pdev)
>               return PTR_ERR(imx6_pcie->pcie);
>       }
>  
> -     if (imx6_pcie->is_imx6sx) {
> +     if (imx6_pcie->variant == IMX6SX) {
>               imx6_pcie->pcie_inbound_axi = devm_clk_get(&pdev->dev,
>                                                          "pcie_inbound_axi");
>               if (IS_ERR(imx6_pcie->pcie_inbound_axi)) {
> @@ -679,8 +689,8 @@ static void imx6_pcie_shutdown(struct platform_device 
> *pdev)
>  }
>  
>  static const struct of_device_id imx6_pcie_of_match[] = {
> -     { .compatible = "fsl,imx6q-pcie", },
> -     { .compatible = "fsl,imx6sx-pcie", },
> +     { .compatible = "fsl,imx6q-pcie",  .data = (void *)IMX6Q,  },
> +     { .compatible = "fsl,imx6sx-pcie", .data = (void *)IMX6SX, },
>       {},
>  };
>  MODULE_DEVICE_TABLE(of, imx6_pcie_of_match);
> -- 
> 2.5.5
> 
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