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SubjectRe: [PATCH v6 12/22] sh: Add PCI host bridge driver for SH7751
On Mon, Jul 04, 2016 at 01:46:32AM +0900, Yoshinori Sato wrote:
> This is an alternative SH7751 PCI driver.
> Existing driver (arch/sh/drivers/pci/pci-sh7751) uses SH specific interface.
> But this driver uses common PCI interface. It is more modern and generic.

I'd like some details here about why we want this new driver. Will
the old one be removed? How should a user choose which one to use?

> Signed-off-by: Yoshinori Sato <ysato@users.sourceforge.jp>
> ---
> .../devicetree/bindings/pci/sh7751-pci.txt | 37 +++
> arch/sh/boards/Kconfig | 1 +
> arch/sh/drivers/Makefile | 2 +
> drivers/pci/host/Kconfig | 7 +
> drivers/pci/host/Makefile | 1 +
> drivers/pci/host/pci-sh7751.c | 327 +++++++++++++++++++++
> 6 files changed, 375 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/pci/sh7751-pci.txt
> create mode 100644 drivers/pci/host/pci-sh7751.c

How do you plan to merge this? It looks like part of a large series,
and I've only seen a few pieces of it. The ones you've posted to
linux-pci seem mostly OK. I have a few minor comments below, but
after you fix those and write some text for the changelogs, I can ack
them and you can merge them along with the rest of the series.

Bjorn

> diff --git a/Documentation/devicetree/bindings/pci/sh7751-pci.txt b/Documentation/devicetree/bindings/pci/sh7751-pci.txt
> new file mode 100644
> index 0000000..2df9af6
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/pci/sh7751-pci.txt
> @@ -0,0 +1,37 @@
> +* Renesas SH7751 PCI host interfaces
> +
> +Required properties:
> + - compatible: "renesas,sh7751-pci" is required.
> + And board specific compatible if fixup required.
> + - reg: contain two entries.
> + first entry: PCI controller register base address and length.
> + second entry: BUS controller register base address and length.
> + - #address-cells: set to <2>
> + - #size-cells: set to <1>
> + - bus-range: PCI bus numbers covered
> + - device_type: set to "pci"
> + - ranges: ranges for the PCI memory and I/O regions.
> + - interrupt-map-mask and interrupt-map: standard PCI properties
> + to define the mapping of the PCI interface to interrupt
> + numbers.
> +
> +Example:
> + pci: pci-controller@fe200000 {
> + compatible = "renesas,sh7751-pci", "iodata,landisk";
> + device_type = "pci";
> + bus-range = <0 0>;
> + #address-cells = <2>;
> + #size-cells = <1>;
> + ranges = <0x02000000 0x00000000 0xfd000000 0xfd000000 0x00000000 0x01000000>,
> + <0x01000000 0x00000000 0xfe240000 0x00000000 0x00000000 0x00040000>;
> + reg = <0xfe200000 0x0400>,
> + <0xff800000 0x0030>;
> + #interrupt-cells = <1>;
> + interrupt-map-mask = <0x1800 0 7>;
> + interrupt-map = <0x0000 0 1 &cpldintc 0 0>,
> + <0x0800 0 1 &cpldintc 1 0>,
> + <0x1000 0 1 &cpldintc 2 0>,
> + <0x1800 0 1 &cpldintc 3 0>,
> + <0x1800 0 2 &cpldintc 0 0>;
> + };
> +};
> diff --git a/arch/sh/boards/Kconfig b/arch/sh/boards/Kconfig
> index b6ff9df..cfde921 100644
> --- a/arch/sh/boards/Kconfig
> +++ b/arch/sh/boards/Kconfig
> @@ -14,6 +14,7 @@ config SH_DEVICE_TREE
> select GENERIC_CALIBRATE_DELAY
> select GENERIC_IOMAP
> select COMMON_CLK
> + select SYS_SUPPORTS_PCI
> help
> Select Board Described by Device Tree to build a kernel that
> does not hard-code any board-specific knowledge but instead uses
> diff --git a/arch/sh/drivers/Makefile b/arch/sh/drivers/Makefile
> index e13f06b..382e86f 100644
> --- a/arch/sh/drivers/Makefile
> +++ b/arch/sh/drivers/Makefile
> @@ -4,7 +4,9 @@
>
> obj-y += dma/
>
> +ifndef CONFIG_SH_DEVICE_TREE
> obj-$(CONFIG_PCI) += pci/
> +endif
> obj-$(CONFIG_SUPERHYWAY) += superhyway/
> obj-$(CONFIG_PUSH_SWITCH) += push-switch.o
> obj-$(CONFIG_HEARTBEAT) += heartbeat.o
> diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
> index 5d2374e..df60505 100644
> --- a/drivers/pci/host/Kconfig
> +++ b/drivers/pci/host/Kconfig
> @@ -245,4 +245,11 @@ config PCIE_ARMADA_8K
> Designware hardware and therefore the driver re-uses the
> Designware core functions to implement the driver.
>
> +config PCI_SH7751
> + bool "Renesas SH7751 On-Chip PCI controller"
> + depends on OF && SUPERH
> + select PCI_HOST_COMMON
> + help
> + Say Y here if you want PCI support on SH7751.
> +
> endmenu
> diff --git a/drivers/pci/host/Makefile b/drivers/pci/host/Makefile
> index 9c8698e..4681e49 100644
> --- a/drivers/pci/host/Makefile
> +++ b/drivers/pci/host/Makefile
> @@ -29,3 +29,4 @@ obj-$(CONFIG_PCIE_QCOM) += pcie-qcom.o
> obj-$(CONFIG_PCI_HOST_THUNDER_ECAM) += pci-thunder-ecam.o
> obj-$(CONFIG_PCI_HOST_THUNDER_PEM) += pci-thunder-pem.o
> obj-$(CONFIG_PCIE_ARMADA_8K) += pcie-armada8k.o
> +obj-$(CONFIG_PCI_SH7751) += pci-sh7751.o
> diff --git a/drivers/pci/host/pci-sh7751.c b/drivers/pci/host/pci-sh7751.c
> new file mode 100644
> index 0000000..21601f1
> --- /dev/null
> +++ b/drivers/pci/host/pci-sh7751.c
> @@ -0,0 +1,327 @@
> +/*
> + * SH7751 PCI driver
> + * Copyright (C) 2016 Yoshinori Sato
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of_address.h>
> +#include <linux/of_pci.h>
> +#include <linux/of_platform.h>
> +#include <linux/pci.h>
> +#include <linux/platform_device.h>
> +#include <linux/io.h>
> +#include "../ecam.h"
> +
> +#define SH7751_PCICONF1 0x4 /* PCI Config Reg 1 */
> +#define SH7751_PCICONF4 0x10 /* PCI Config Reg 4 */
> +#define SH7751_PCICONF5 0x14 /* PCI Config Reg 5 */
> +#define SH7751_PCICONF6 0x18 /* PCI Config Reg 6 */
> +#define SH4_PCICR 0x100 /* PCI Control Register */
> + #define SH4_PCICR_PREFIX 0xA5000000 /* CR prefix for write */

Follow the indentation style of include/uapi/linux/pci_regs.h,
drivers/pci/host/pcie-rcar.c, drivers/pci/host/pci-mvebu.c, etc.:

#define SH4_PCICR 0x100
#define SH4_PCICR_PREFIX 0xA5000000

> + #define SH4_PCICR_FTO BIT(10) /* TRDY/IRDY Enable */
> + #define SH4_PCICR_TRSB BIT(9) /* Target Read Single */
> + #define SH4_PCICR_BSWP BIT(8) /* Target Byte Swap */
> + #define SH4_PCICR_PLUP BIT(7) /* Enable PCI Pullup */

The above are unused and can be omitted.

> + #define SH4_PCICR_ARBM BIT(6) /* PCI Arbitration Mode */
> +#define SH4_PCICR_MD (BIT(4) | BIT(5)) /* MD9 and MD10 status */

Indentation error (should match other fields above). Also, unused, so
can just be omitted.

> + #define SH4_PCICR_SERR BIT(3) /* SERR output assert */
> + #define SH4_PCICR_INTA BIT(2) /* INTA output assert */
> + #define SH4_PCICR_PRST BIT(1) /* PCI Reset Assert */

Above are unused.

> + #define SH4_PCICR_CFIN BIT(0) /* Central Fun. Init Done */
> +#define SH4_PCILSR0 0x104 /* PCI Local Space Register0 */
> +#define SH4_PCILSR1 0x108 /* PCI Local Space Register1 */

Unused.

> +#define SH4_PCILAR0 0x10C /* PCI Local Addr Register1 */
> +#define SH4_PCILAR1 0x110 /* PCI Local Addr Register1 */
> +#define SH4_PCIINTM 0x118 /* PCI Interrupt Mask */
> + #define SH4_PCIINTM_TTADIM BIT(14) /* Target-target abort interrupt */
> + #define SH4_PCIINTM_TMTOIM BIT(9) /* Target retry timeout */
> + #define SH4_PCIINTM_MDEIM BIT(8) /* Master function disable error */
> + #define SH4_PCIINTM_APEDIM BIT(7) /* Address parity error detection */
> + #define SH4_PCIINTM_SDIM BIT(6) /* SERR detection */
> + #define SH4_PCIINTM_DPEITWM BIT(5) /* Data parity error for target write */
> + #define SH4_PCIINTM_PEDITRM BIT(4) /* PERR detection for target read */
> + #define SH4_PCIINTM_TADIMM BIT(3) /* Target abort for master */
> + #define SH4_PCIINTM_MADIMM BIT(2) /* Master abort for master */
> + #define SH4_PCIINTM_MWPDIM BIT(1) /* Master write data parity error */
> + #define SH4_PCIINTM_MRDPEIM BIT(0) /* Master read data parity error */

Field names are unused. You do write 0xc3ff to SH4_PCIINTM, but it's
a pain to match that up with these definitions. Either write out the
masks here, e.g., "#define SH4_PCIINTM_MRDPEIM 0x00000001", or build
up the SH4_PCIINTM from these definitions, or both.

> +#define SH4_PCIAINTM 0x134 /* Arbiter Int. Mask Register */
> +#define SH4_PCIPAR 0x1C0 /* PIO Address Register */
> + #define SH4_PCIPAR_CFGEN 0x80000000 /* Configuration Enable */
> + #define SH4_PCIPAR_BUSNO 0x00FF0000 /* Config. Bus Number */
> + #define SH4_PCIPAR_DEVNO 0x0000FF00 /* Config. Device Number */
> + #define SH4_PCIPAR_REGAD 0x000000FC /* Register Address Number */

Field names unused. At least SH4_PCIPAR_CFGEN *could* be used in
CONFIG_CMD() below.

> +#define SH4_PCIPINT 0x1CC /* Power Mgmnt Int. Register */
> + #define SH4_PCIPINT_D3 0x00000002 /* D3 Pwr Mgmt. Interrupt */
> + #define SH4_PCIPINT_D0 0x00000001 /* D0 Pwr Mgmt. Interrupt */
> +#define SH4_PCICLKR 0x1D4 /* Clock Ctrl. Register */
> +/* For definitions of BCR, MCR see ... */

See ... what?

> +#define SH4_PCIBCR1 0x1E0 /* Memory BCR1 Register */
> + #define SH4_PCIMBR0 SH4_PCIBCR1

Unused.

> +#define SH4_PCIBCR2 0x1E4 /* Memory BCR2 Register */
> + #define SH4_PCIMBMR0 SH4_PCIBCR2

Unused.

> +#define SH4_PCIWCR1 0x1E8 /* Wait Control 1 Register */
> +#define SH4_PCIWCR2 0x1EC /* Wait Control 2 Register */
> +#define SH4_PCIWCR3 0x1F0 /* Wait Control 3 Register */
> + #define SH4_PCIMBR2 SH4_PCIWCR3

Unused.

> +#define SH4_PCIMCR 0x1F4 /* Memory Control Register */
> +#define SH4_PCIPDR 0x220 /* Port IO Data Register */
> +
> +/* Platform Specific Values */
> +#define SH7751_VENDOR_ID 0x1054
> +#define SH7751_DEVICE_ID 0x3505
> +#define SH7751R_DEVICE_ID 0x350e
> +
> +/* Memory Control Registers */
> +#define SH7751_BCR1 0x0000 /* Memory BCR1 Register */
> +#define SH7751_BCR2 0x0004 /* Memory BCR2 Register */
> +#define SH7751_BCR3 0x0050 /* Memory BCR3 Register */

Unused.

> +#define SH7751_WCR1 0x0008 /* Wait Control 1 Register */
> +#define SH7751_WCR2 0x000C /* Wait Control 2 Register */
> +#define SH7751_WCR3 0x0010 /* Wait Control 3 Register */
> +#define SH7751_MCR 0x0014 /* Memory Control Register */
> +
> +#define pcic_writel(val, reg) iowrite32(val, pci_reg_base + (reg))
> +#define pcic_readl(reg) ioread32(pci_reg_base + (reg))
> +
> +/*
> + * PCIC fixups
> + */
> +
> +#define PCIMCR_MRSET 0x40000000
> +#define PCIMCR_RFSH 0x00000004
> +
> +static void __init landisk_fixup(void __iomem *pci_reg_base, void __iomem *bcr)
> +{
> + unsigned long bcr1, mcr;
> +
> + bcr1 = ioread32(bcr + SH7751_BCR1);
> + bcr1 |= 0x00080000; /* Enable Bit 19 BREQEN, set PCIC to slave */
> + pcic_writel(bcr1, SH4_PCIBCR1);
> +
> + mcr = ioread32(bcr + SH7751_MCR);
> + mcr &= (~PCIMCR_MRSET) & (~PCIMCR_RFSH);
> + pcic_writel(mcr, SH4_PCIMCR);
> +
> + pcic_writel(0x0c000000, PCI_BASE_ADDRESS_1);
> + pcic_writel(0xd0000000, PCI_BASE_ADDRESS_2);
> + pcic_writel(0x0c000000, SH4_PCILAR0);
> + pcic_writel(0x00000000, SH4_PCILAR1);
> +}
> +
> +static void __init r2dplus_fixup(void __iomem *pci_reg_base, void __iomem *bcr)
> +{
> + unsigned long bcr1, mcr;
> +
> + bcr1 = ioread32(bcr + SH7751_BCR1);
> + bcr1 |= 0x40080000; /* Enable Bit 19 BREQEN, set PCIC to slave */
> + pcic_writel(bcr1, SH4_PCIBCR1);
> +
> + /* Enable all interrupts, so we known what to fix */
> + pcic_writel(0x0000c3ff, SH4_PCIINTM);
> + pcic_writel(0x0000380f, SH4_PCIAINTM);
> +
> + pcic_writel(0xfb900047, SH7751_PCICONF1);
> + pcic_writel(0xab000001, SH7751_PCICONF4);
> +
> + mcr = ioread32(bcr + SH7751_MCR);
> + mcr &= (~PCIMCR_MRSET) & (~PCIMCR_RFSH);
> + pcic_writel(mcr, SH4_PCIMCR);
> +
> + pcic_writel(0x0c000000, SH7751_PCICONF5);
> + pcic_writel(0xd0000000, SH7751_PCICONF6);
> + pcic_writel(0x0c000000, SH4_PCILAR0);
> + pcic_writel(0x00000000, SH4_PCILAR1);
> +}
> +
> +/*
> + * Direct access to PCI hardware...
> + */
> +#define CONFIG_CMD(bus, devfn, where) \
> + (0x80000000 | (bus->number << 16) | (devfn << 8) | (where & ~3))
> +
> +/*
> + * Functions for accessing PCI configuration space with type 1 accesses
> + */
> +static void __iomem *sh7751_map_bus(struct pci_bus *bus,
> + unsigned int devfn, int where)
> +{
> + struct pci_config_window *cfg = bus->sysdata;
> + void __iomem *pci_reg_base = (void __iomem *)cfg->res.start;
> +
> + pcic_writel(CONFIG_CMD(bus, devfn, where), SH4_PCIPAR);
> + return pci_reg_base + SH4_PCIPDR;
> +}
> +
> +static const struct of_device_id fixup_of_match[] = {
> + { .compatible = "iodata,landisk-pci", .data = landisk_fixup, },
> + { .compatible = "renesas,r2dplus-pci", .data = r2dplus_fixup, },
> + { },
> +};
> +
> +static const struct of_device_id sh7751_pci_of_match[] = {
> + { .compatible = "renesas,sh7751-pci", },
> + { },
> +};
> +MODULE_DEVICE_TABLE(of, sh7751_pci_of_match);
> +
> +static resource_size_t sh7751_align_resource(struct pci_dev *dev,
> + const struct resource *res,
> + resource_size_t start,
> + resource_size_t size,
> + resource_size_t align)
> +{
> + if (res->flags & IORESOURCE_IO) {
> + if (start < PCIBIOS_MIN_IO + 0x1000)
> + start = PCIBIOS_MIN_IO + 0x1000;
> +
> + /*
> + * Put everything into 0x00-0xff region modulo 0x400.
> + */
> + if (start & 0x300)
> + start = (start + 0x3ff) & ~0x3ff;
> + }
> +
> + return start;
> +}
> +
> +static void __init set_pci_bcr(void __iomem *pci_reg_base,
> + void __iomem *bcr,
> + unsigned int area)
> +{
> + unsigned long word;
> +
> + word = ioread32(bcr + SH7751_BCR1);
> + /* check BCR for SDRAM in area */
> + if (((word >> area) & 1) == 0) {
> + pr_info("PCI: Area %d is not configured for SDRAM. BCR1=0x%lx\n",
> + area, word);

Use dev_info() so we can associate the message with a device and driver.

> + return;
> + }
> + pcic_writel(word, SH4_PCIBCR1);
> +
> + word = ioread16(bcr + SH7751_BCR2);
> + /* check BCR2 for 32bit SDRAM interface*/
> + if (((word >> (area << 1)) & 0x3) != 0x3) {
> + pr_info("PCI: Area %d is not 32 bit SDRAM. BCR2=0x%lx\n",
> + area, word);

dev_info()

> + return;
> + }
> + pcic_writel(word, SH4_PCIBCR2);
> +}
> +
> +static __init int sh7751_cfg_init(struct device *dev,
> + struct pci_config_window *cfg)
> +{
> + cfg->priv = sh7751_align_resource;
> + return 0;
> +}
> +
> +static struct pci_ecam_ops ecm_ops __initdata = {
> + .init = sh7751_cfg_init,
> + .pci_ops = {
> + .read = pci_generic_config_read32,
> + .write = pci_generic_config_write32,
> + .map_bus = sh7751_map_bus,
> + }
> +};
> +
> +static __init int sh7751_pci_probe(struct platform_device *pdev)
> +{
> + struct resource *res;
> + u32 id;
> + u32 reg, word;
> + void __iomem *pci_reg_base;
> + void __iomem *bcr;
> + const struct of_device_id *match;
> + void (*fixup_fn)(void __iomem *pci_reg_base, void __iomem *bcr);
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + pci_reg_base = ioremap(res->start, resource_size(res));
> + if (IS_ERR(pci_reg_base))
> + return PTR_ERR(pci_reg_base);
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
> + bcr = ioremap(res->start, resource_size(res));
> + if (IS_ERR(bcr))
> + return PTR_ERR(bcr);
> +
> + /* check for SH7751/SH7751R hardware */
> + id = pcic_readl(PCI_VENDOR_ID);
> + if (id != ((SH7751_DEVICE_ID << 16) | SH7751_VENDOR_ID) &&
> + id != ((SH7751R_DEVICE_ID << 16) | SH7751_VENDOR_ID)) {
> + pr_warn("PCI: This is not an SH7751(R)\n");

dev_warn()

> + return -ENODEV;
> + }
> + dev_info(&pdev->dev, "PCI core found at %pR\n",
> + pci_reg_base);
> +
> + /* Set the BCRs to enable PCI access */
> + reg = ioread32(bcr);
> + reg |= 0x80000;
> + iowrite32(reg, bcr);
> +
> + /* Turn the clocks back on (not done in reset)*/
> + pcic_writel(0, SH4_PCICLKR);
> + /* Clear Powerdown IRQs (not done in reset) */
> + word = SH4_PCIPINT_D3 | SH4_PCIPINT_D0;
> + pcic_writel(word, SH4_PCIPINT);
> +
> + /* set the command/status bits to:
> + * Wait Cycle Control + Parity Enable + Bus Master +
> + * Mem space enable
> + */

Multi-line comment style is:

/*
* set the command/...
* ...
*/

> + word = PCI_COMMAND_WAIT | PCI_COMMAND_PARITY |
> + PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY;
> + pcic_writel(word, PCI_COMMAND);
> +
> + /* define this host as the host bridge */
> + word = PCI_BASE_CLASS_BRIDGE << 24;
> + pcic_writel(word, PCI_CLASS_REVISION);
> +
> + /* Set IO and Mem windows to local address
> + * Make PCI and local address the same for easy 1 to 1 mapping
> + */
> + word = memory_end - memory_start - 1;
> + pcic_writel(word, SH4_PCILSR0);
> + /* Set the values on window 0 PCI config registers */
> + word = P2SEGADDR(__pa(memory_start));
> + pcic_writel(word, SH4_PCILAR0);
> + pcic_writel(word, PCI_BASE_ADDRESS_1);
> +
> + set_pci_bcr(pci_reg_base, bcr, (__pa(memory_start) >> 27) & 0x07);
> +
> + /* configure the wait control registers */
> + word = ioread32(bcr + SH7751_WCR1);
> + pcic_writel(word, SH4_PCIWCR1);
> + word = ioread32(bcr + SH7751_WCR2);
> + pcic_writel(word, SH4_PCIWCR2);
> + word = ioread32(bcr + SH7751_WCR3);
> + pcic_writel(word, SH4_PCIWCR3);
> + word = ioread32(bcr + SH7751_MCR);
> + pcic_writel(word, SH4_PCIMCR);
> +
> + match = of_match_node(fixup_of_match, pdev->dev.of_node);
> + if (match) {
> + fixup_fn = match->data;
> + fixup_fn(pci_reg_base, bcr);
> + }
> + /*
> + * SH7751 init done, set central function init complete
> + * use round robin mode to stop a device starving/overruning
> + */
> + word = SH4_PCICR_PREFIX | SH4_PCICR_CFIN | SH4_PCICR_ARBM;
> + pcic_writel(word, SH4_PCICR);
> +
> + return pci_host_common_probe(pdev, &ecm_ops);
> +}
> +
> +static __refdata struct platform_driver sh7751_pci_driver = {
> + .driver = {
> + .name = "sh7751-pci",
> + .of_match_table = sh7751_pci_of_match,
> + .suppress_bind_attrs = true,
> + },
> + .probe = sh7751_pci_probe,
> +};
> +builtin_platform_driver(sh7751_pci_driver);
> --
> 2.7.0
>

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