Re: [PATCH] PCI: hisi: Add support for HiSilicon Hip06 PCIe host bridge controllers

[Bjorn Helgaas]

Hi Gabriele,

On Wed, Nov 18, 2015 at 05:51:09PM +0800, Gabriele Paoloni wrote:
> From: gabriele paoloni <gabriele.paoloni@xxxxxxxxxx>

Would you mind fixing wherever this comes from?  I've been manually
fixing it to match your signed-off-by (which is conventionally
capitalized), but it'd be handier if you fixed it on your end.

> This patch adds support for HiSilicon Hip06 SoC that implements
> v2 HW IP of the PCIe Host Bridge controller.
> Hip05 SoC references have been replaced with v1-Hip05
> and references to v2-Hip06 have been added.
> Documentation has been updated to include Hip06 and the DT
> example also has been updated accordingly.
> Finally Gabriele Paoloni has been added as maintainer of the
> driver
> 
> Signed-off-by: Gabriele Paoloni <gabriele.paoloni@xxxxxxxxxx>
> Signed-off-by: Zhou Wang <wangzhou1@xxxxxxxxxxxxx>

This order is wrong.  This order says that Zhou took something from
you and posted it.  But this email came from you, so either the order
should be reversed, or it should be "Reviewed-by" or "Acked-by" Zhou.

Since Zhou is the current HiSi maintainer, I do want to see this patch
either posted directly by him or acked by him.

> ---
> This patch is based on top of Arnd Bergmann patch
> [PATCH] PCI: hisi: fix deferred probing
> ---
>  .../devicetree/bindings/pci/hisilicon-pcie.txt     | 16 ++--
>  MAINTAINERS                                        |  1 +
>  drivers/pci/host/Kconfig                           |  5 +-
>  drivers/pci/host/pcie-hisi.c                       | 91 ++++++++++++++++++----
>  4 files changed, 90 insertions(+), 23 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/pci/hisilicon-pcie.txt b/Documentation/devicetree/bindings/pci/hisilicon-pcie.txt
> index 17c6ed9..3eee49a 100644
> --- a/Documentation/devicetree/bindings/pci/hisilicon-pcie.txt
> +++ b/Documentation/devicetree/bindings/pci/hisilicon-pcie.txt
> @@ -1,4 +1,4 @@
> -HiSilicon PCIe host bridge DT description
> +HiSilicon Hip05 and Hip06 PCIe host bridge DT description
>  
>  HiSilicon PCIe host controller is based on Designware PCI core.
>  It shares common functions with PCIe Designware core driver and inherits
> @@ -7,8 +7,8 @@ Documentation/devicetree/bindings/pci/designware-pci.txt.
>  
>  Additional properties are described here:
>  
> -Required properties:
> -- compatible: Should contain "hisilicon,hip05-pcie".
> +Required properties
> +- compatible: Should contain "hisilicon,v1-pcie-hip05" or "hisilicon,v2-pcie-hip06".

Why are you adding "v1" and "v2" to these strings?  Isn't "hip05" vs
"hip06" enough by itself?

>  - reg: Should contain rc_dbi, config registers location and length.
>  - reg-names: Must include the following entries:
>    "rc_dbi": controller configuration registers;
> @@ -20,10 +20,14 @@ Optional properties:
>  - status: Either "ok" or "disabled".
>  - dma-coherent: Present if DMA operations are coherent.
>  
> -Example:
> +Hip05/Hip06 Example:
>  	pcie@0xb0080000 {
> -		compatible = "hisilicon,hip05-pcie", "snps,dw-pcie";
> +		compatible = "hisilicon,v1-pcie-hip05", "snps,dw-pcie";
>  		reg = <0 0xb0080000 0 0x10000>, <0x220 0x00000000 0 0x2000>;
> +/* for v2 HW IP use
> + *		compatible = "hisilicon,v2-pcie-hip06", "snps,dw-pcie";
> + *		reg = <0 0xa0090000 0 0x10000>, <0 0xa8000000 0 0x2000>;
> + */

The only thing changing here is the "compatible" string, so I think it
clutters up the example to include these two lines.  It almost made me
overlook the "hisilicon,hip05-pcie" change (which I think should be in
a separate patch).

>  		reg-names = "rc_dbi", "config";
>  		bus-range = <0  15>;
>  		msi-parent = <&its_pcie>;
> @@ -41,4 +45,4 @@ Example:
>  				  0x0 0 0 3 &mbigen_pcie 3 12
>  				  0x0 0 0 4 &mbigen_pcie 4 13>;
>  		status = "ok";
> -	};
> +	};
> \ No newline at end of file

Spurious change that we don't want.

> diff --git a/MAINTAINERS b/MAINTAINERS
> index 7af7f4a..3f97cf1 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -8195,6 +8195,7 @@ F:	drivers/pci/host/pci-xgene-msi.c
>  
>  PCIE DRIVER FOR HISILICON
>  M:	Zhou Wang <wangzhou1@xxxxxxxxxxxxx>
> +M:	Gabriele Paoloni <gabriele.paoloni@xxxxxxxxxx>
>  L:	linux-pci@xxxxxxxxxxxxxxx
>  S:	Maintained
>  F:	Documentation/devicetree/bindings/pci/hisilicon-pcie.txt
> diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
> index f131ba9..f5c58cf 100644
> --- a/drivers/pci/host/Kconfig
> +++ b/drivers/pci/host/Kconfig
> @@ -166,10 +166,11 @@ config PCIE_ALTERA_MSI
>  
>  config PCI_HISI
>  	depends on OF && ARM64
> -	bool "HiSilicon SoC HIP05 PCIe controller"
> +	bool "HiSilicon Hip05 and Hip06 SoCs PCIe controllers"
>  	select PCIEPORTBUS
>  	select PCIE_DW
>  	help
> -	  Say Y here if you want PCIe controller support on HiSilicon HIP05 SoC
> +	  Say Y here if you want PCIe controller support on SoCs supporting
> +	  HiSilicon Hip05 and Hip06 SoCs

Looks like an extra "support" or "supporting" in this sentence.

>  endmenu
> diff --git a/drivers/pci/host/pcie-hisi.c b/drivers/pci/host/pcie-hisi.c
> index 163671a..1210685 100644
> --- a/drivers/pci/host/pcie-hisi.c
> +++ b/drivers/pci/host/pcie-hisi.c
> @@ -1,10 +1,11 @@
>  /*
> - * PCIe host controller driver for HiSilicon Hip05 SoC
> + * PCIe host bridge controller driver for HiSilicon SoCs

"host bridge controller driver" is really a mouthful.  "host
controller driver" is still accurate and probably enough.

>   *
>   * Copyright (C) 2015 HiSilicon Co., Ltd. http://www.hisilicon.com
>   *
> - * Author: Zhou Wang <wangzhou1@xxxxxxxxxxxxx>
> - *         Dacai Zhu <zhudacai@xxxxxxxxxxxxx>
> + * Authors: Zhou Wang <wangzhou1@xxxxxxxxxxxxx>
> + *          Dacai Zhu <zhudacai@xxxxxxxxxxxxx>
> + *          Gabriele Paoloni <gabriele.paoloni@xxxxxxxxxx>
>   *
>   * This program is free software; you can redistribute it and/or modify
>   * it under the terms of the GNU General Public License version 2 as
> @@ -16,21 +17,35 @@
>  #include <linux/of_address.h>
>  #include <linux/of_pci.h>
>  #include <linux/platform_device.h>
> +#include <linux/of_device.h>
>  #include <linux/regmap.h>
>  
>  #include "pcie-designware.h"
>  
> -#define PCIE_SUBCTRL_SYS_STATE4_REG                     0x6818
> -#define PCIE_LTSSM_LINKUP_STATE                         0x11
> -#define PCIE_LTSSM_STATE_MASK                           0x3F
> +#define PCIE_HOST_V1                                 0x1
> +#define PCIE_HOST_V2                                 0x2
> +
> +#define PCIE_LTSSM_LINKUP_STATE                      0x11
> +#define PCIE_LTSSM_STATE_MASK                        0x3F
> +#define PCIE_SUBCTRL_SYS_STATE4_REG                  0x6818
> +#define PCIE_SYS_STATE4                              0x31c
> +#define PCIE_V2_CTRL_OFF                             0x1000

This mixes up some reordering and whitespace changes with the actual
Hip06 changes.  But I guess they're so trivial it's probably not worth
splitting them out.  But since you are changing them anyway, please
convert them to use tabs instead of spaces.

>  #define to_hisi_pcie(x)	container_of(x, struct hisi_pcie, pp)
>  
> +struct hisi_pcie;
> +
> +struct pcie_soc_ops {
> +	int (*hisi_pcie_link_up)(struct hisi_pcie *pcie);
> +	u32 soc_type;
> +};
> +
>  struct hisi_pcie {
>  	struct regmap *subctrl;
>  	void __iomem *reg_base;
>  	u32 port_id;
>  	struct pcie_port pp;
> +	struct pcie_soc_ops *soc_ops;
>  };
>  
>  static inline void hisi_pcie_apb_writel(struct hisi_pcie *pcie,
> @@ -44,7 +59,7 @@ static inline u32 hisi_pcie_apb_readl(struct hisi_pcie *pcie, u32 reg)
>  	return readl(pcie->reg_base + reg);
>  }
>  
> -/* Hip05 PCIe host only supports 32-bit config access */
> +/* HipXX PCIe host only supports 32-bit config access */
>  static int hisi_pcie_cfg_read(struct pcie_port *pp, int where, int size,
>  			      u32 *val)
>  {
> @@ -67,7 +82,7 @@ static int hisi_pcie_cfg_read(struct pcie_port *pp, int where, int size,
>  	return PCIBIOS_SUCCESSFUL;
>  }
>  
> -/* Hip05 PCIe host only supports 32-bit config access */
> +/* HipXX PCIe host only supports 32-bit config access */
>  static int hisi_pcie_cfg_write(struct pcie_port *pp, int where, int  size,
>  				u32 val)
>  {
> @@ -96,13 +111,8 @@ static int hisi_pcie_cfg_write(struct pcie_port *pp, int where, int  size,
>  
>  static int hisi_pcie_link_up(struct pcie_port *pp)
>  {
> -	u32 val;
>  	struct hisi_pcie *hisi_pcie = to_hisi_pcie(pp);
> -
> -	regmap_read(hisi_pcie->subctrl, PCIE_SUBCTRL_SYS_STATE4_REG +
> -		    0x100 * hisi_pcie->port_id, &val);
> -
> -	return ((val & PCIE_LTSSM_STATE_MASK) == PCIE_LTSSM_LINKUP_STATE);
> +	return hisi_pcie->soc_ops->hisi_pcie_link_up(hisi_pcie);
>  }
>  
>  static struct pcie_host_ops hisi_pcie_host_ops = {
> @@ -143,7 +153,9 @@ static int hisi_pcie_probe(struct platform_device *pdev)
>  {
>  	struct hisi_pcie *hisi_pcie;
>  	struct pcie_port *pp;
> +	const struct of_device_id *match;
>  	struct resource *reg;
> +	struct device_driver *driver;
>  	int ret;
>  
>  	hisi_pcie = devm_kzalloc(&pdev->dev, sizeof(*hisi_pcie), GFP_KERNEL);
> @@ -152,6 +164,10 @@ static int hisi_pcie_probe(struct platform_device *pdev)
>  
>  	pp = &hisi_pcie->pp;
>  	pp->dev = &pdev->dev;
> +	driver = (pdev->dev).driver;
> +
> +	match = of_match_device(driver->of_match_table, &pdev->dev);
> +	hisi_pcie->soc_ops = (struct pcie_soc_ops *) match->data;
>  
>  	hisi_pcie->subctrl =
>  	syscon_regmap_lookup_by_compatible("hisilicon,pcie-sas-subctrl");
> @@ -180,11 +196,51 @@ static int hisi_pcie_probe(struct platform_device *pdev)
>  	return 0;
>  }
>  
> +/* Check if the link is up for V1 PCIe HW IP*/

These comments aren't really necessary; it's obvious from the names
what's going on.  I'd use "hip05" and "hip06" because they seem more
descriptive than "v1" and "v2", but I'm a little confused about what
your conventional names are.

> +static int hisi_pcie_link_up_v1(struct hisi_pcie *hisi_pcie)
> +{
> +	u32 val;
> +
> +	regmap_read(hisi_pcie->subctrl, PCIE_SUBCTRL_SYS_STATE4_REG +
> +		    0x100 * hisi_pcie->port_id, &val);
> +
> +	return ((val & PCIE_LTSSM_STATE_MASK) == PCIE_LTSSM_LINKUP_STATE);
> +}

I'd put these functions just above the hisi_pcie_link_up() wrapper
because it makes it easier for human code readers, but that's a
nit-pick.  It might also make the patch easier to read because it
might show as a simple function rename rather than "remove and add
elsewhere."

> +/* Check if the link is up for V2 PCIe HW IP */
> +static int hisi_pcie_link_up_v2(struct hisi_pcie *hisi_pcie)
> +{
> +	u32 val;
> +
> +	val = hisi_pcie_apb_readl(hisi_pcie, PCIE_V2_CTRL_OFF +
> +			PCIE_SYS_STATE4);

It looks like hip05 support 4 ports (0, 1, 2, 3).  Does hip06 only
support one port?  The v1 link_up() function uses hisi_pcie->port_id,
but this one doesn't.

> +	return ((val & PCIE_LTSSM_STATE_MASK) == PCIE_LTSSM_LINKUP_STATE);
> +}
> +
> +static struct pcie_soc_ops v2_ops = {
> +		&hisi_pcie_link_up_v2,
> +		PCIE_HOST_V2

I don't see PCI_HOST_V2 and PCI_HOST_V1 being used by anything.

> +};
> +
> +static struct pcie_soc_ops v1_ops = {
> +		&hisi_pcie_link_up_v1,
> +		PCIE_HOST_V1
> +};
> +
>  static const struct of_device_id hisi_pcie_of_match[] = {
> -	{.compatible = "hisilicon,hip05-pcie",},
> +	{
> +			.compatible = "hisilicon,v1-pcie-hip05",

Doesn't this break the driver for any DTs in the field with
"hisilicon,hip05-pcie"?  I don't understand why you need to change
this, but if you do need to, I think it should be a separate patch by
itself so it's more obvious.

> +			.data	    = (void *) &v1_ops,
> +	},
> +	{
> +			.compatible = "hisilicon,v2-pcie-hip06",
> +			.data	    = (void *) &v2_ops,
> +	},
>  	{},
>  };
>  
> +
>  MODULE_DEVICE_TABLE(of, hisi_pcie_of_match);
>  
>  static struct platform_driver hisi_pcie_driver = {
> @@ -196,3 +252,8 @@ static struct platform_driver hisi_pcie_driver = {
>  };
>  
>  module_platform_driver(hisi_pcie_driver);
> +
> +MODULE_AUTHOR("Zhou Wang <wangzhou1@xxxxxxxxxxxxx>");
> +MODULE_AUTHOR("Dacai Zhu <zhudacai@xxxxxxxxxxxxx>");
> +MODULE_AUTHOR("Gabriele Paoloni <gabriele.paoloni@xxxxxxxxxx>");
> +MODULE_LICENSE("GPL v2");
> -- 
> 2.1.4
> 
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