Re: [PATCH] PCI: rcar (usb): DT can override default window settings

From: Rob Herring
Date: Thu Nov 05 2015 - 08:49:58 EST


On Tue, Nov 03, 2015 at 04:19:26PM +0000, Phil Edworthy wrote:
> If the dtb specifies dma-ranges, we use those values. Otherwise, we
> default to the values that were previously hardcoded into the driver.
>
> Signed-off-by: Phil Edworthy <phil.edworthy@xxxxxxxxxxx>
> ---
> .../devicetree/bindings/pci/pci-rcar-gen2.txt | 6 ++

Acked-by: Rob Herring <robh@xxxxxxxxxx>

> drivers/pci/host/pci-rcar-gen2.c | 76 +++++++++++++++++++++-
> 2 files changed, 79 insertions(+), 3 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/pci/pci-rcar-gen2.txt b/Documentation/devicetree/bindings/pci/pci-rcar-gen2.txt
> index 7fab84b..891463c 100644
> --- a/Documentation/devicetree/bindings/pci/pci-rcar-gen2.txt
> +++ b/Documentation/devicetree/bindings/pci/pci-rcar-gen2.txt
> @@ -24,6 +24,11 @@ Required properties:
> - interrupt-map-mask: standard property that helps to define the interrupt
> mapping.
>
> +Optional properties:
> +- dma-ranges: a single range for the inbound memory region. If not supplied,
> + defaults to 1GiB at 0x40000000. Note there are hardware restrictions on the
> + allowed combinations of address and size.
> +
> Example SoC configuration:
>
> pci0: pci@ee090000 {
> @@ -38,6 +43,7 @@ Example SoC configuration:
> #address-cells = <3>;
> #size-cells = <2>;
> #interrupt-cells = <1>;
> + dma-ranges = <0x42000000 0 0x40000000 0 0x40000000 0 0x40000000>;
> interrupt-map-mask = <0xff00 0 0 0x7>;
> interrupt-map = <0x0000 0 0 1 &gic 0 108 IRQ_TYPE_LEVEL_HIGH
> 0x0800 0 0 1 &gic 0 108 IRQ_TYPE_LEVEL_HIGH
> diff --git a/drivers/pci/host/pci-rcar-gen2.c b/drivers/pci/host/pci-rcar-gen2.c
> index c4f64bf..6295116 100644
> --- a/drivers/pci/host/pci-rcar-gen2.c
> +++ b/drivers/pci/host/pci-rcar-gen2.c
> @@ -15,6 +15,7 @@
> #include <linux/io.h>
> #include <linux/kernel.h>
> #include <linux/module.h>
> +#include <linux/of_address.h>
> #include <linux/of_pci.h>
> #include <linux/pci.h>
> #include <linux/platform_device.h>
> @@ -102,6 +103,8 @@ struct rcar_pci_priv {
> unsigned busnr;
> int irq;
> unsigned long window_size;
> + unsigned long window_addr;
> + unsigned long window_pci;
> };
>
> /* PCI configuration space operations */
> @@ -239,8 +242,8 @@ static int rcar_pci_setup(int nr, struct pci_sys_data *sys)
> RCAR_PCI_ARBITER_PCIBP_MODE;
> iowrite32(val, reg + RCAR_PCI_ARBITER_CTR_REG);
>
> - /* PCI-AHB mapping: 0x40000000 base */
> - iowrite32(0x40000000 | RCAR_PCIAHB_PREFETCH16,
> + /* PCI-AHB mapping */
> + iowrite32(priv->window_addr | RCAR_PCIAHB_PREFETCH16,
> reg + RCAR_PCIAHB_WIN1_CTR_REG);
>
> /* AHB-PCI mapping: OHCI/EHCI registers */
> @@ -251,7 +254,7 @@ static int rcar_pci_setup(int nr, struct pci_sys_data *sys)
> iowrite32(RCAR_AHBPCI_WIN1_HOST | RCAR_AHBPCI_WIN_CTR_CFG,
> reg + RCAR_AHBPCI_WIN1_CTR_REG);
> /* Set PCI-AHB Window1 address */
> - iowrite32(0x40000000 | PCI_BASE_ADDRESS_MEM_PREFETCH,
> + iowrite32(priv->window_pci | PCI_BASE_ADDRESS_MEM_PREFETCH,
> reg + PCI_BASE_ADDRESS_1);
> /* Set AHB-PCI bridge PCI communication area address */
> val = priv->cfg_res->start + RCAR_AHBPCI_PCICOM_OFFSET;
> @@ -284,6 +287,64 @@ static struct pci_ops rcar_pci_ops = {
> .write = pci_generic_config_write,
> };
>
> +static int pci_dma_range_parser_init(struct of_pci_range_parser *parser,
> + struct device_node *node)
> +{
> + const int na = 3, ns = 2;
> + int rlen;
> +
> + parser->node = node;
> + parser->pna = of_n_addr_cells(node);
> + parser->np = parser->pna + na + ns;
> +
> + parser->range = of_get_property(node, "dma-ranges", &rlen);
> + if (!parser->range)
> + return -ENOENT;
> +
> + parser->end = parser->range + rlen / sizeof(__be32);
> + return 0;
> +}
> +
> +static int rcar_pci_parse_map_dma_ranges(struct rcar_pci_priv *pci,
> + struct device_node *np)
> +{
> + struct of_pci_range range;
> + struct of_pci_range_parser parser;
> + int index = 0;
> +
> + /* Failure to parse is ok as we fall back to defaults */
> + if (pci_dma_range_parser_init(&parser, np))
> + return 0;
> +
> + /* Get the dma-ranges from DT */
> + for_each_of_pci_range(&parser, &range) {
> + /* Hardware only allows one inbound 32-bit range */
> + if (index)
> + return -EINVAL;
> +
> + pci->window_addr = (unsigned long)range.cpu_addr;
> + pci->window_pci = (unsigned long)range.pci_addr;
> + pci->window_size = (unsigned long)range.size;
> +
> + /* Catch HW limitations */
> + if (!(range.flags & IORESOURCE_PREFETCH)) {
> + dev_err(pci->dev, "window must be prefetchable\n");
> + return -EINVAL;
> + }
> + if (pci->window_addr) {
> + u32 lowaddr = 1 << (ffs(pci->window_addr) - 1);
> +
> + if (lowaddr < pci->window_size) {
> + dev_err(pci->dev, "invalid window size/addr\n");
> + return -EINVAL;
> + }
> + }
> + index++;
> + }
> +
> + return 0;
> +}
> +
> static int rcar_pci_probe(struct platform_device *pdev)
> {
> struct resource *cfg_res, *mem_res;
> @@ -329,6 +390,9 @@ static int rcar_pci_probe(struct platform_device *pdev)
> return priv->irq;
> }
>
> + /* default window addr and size if not specified in DT */
> + priv->window_addr = 0x40000000;
> + priv->window_pci = 0x40000000;
> priv->window_size = SZ_1G;
>
> if (pdev->dev.of_node) {
> @@ -344,6 +408,12 @@ static int rcar_pci_probe(struct platform_device *pdev)
> priv->busnr = busnr.start;
> if (busnr.end != busnr.start)
> dev_warn(&pdev->dev, "only one bus number supported\n");
> +
> + ret = rcar_pci_parse_map_dma_ranges(priv, pdev->dev.of_node);
> + if (ret < 0) {
> + dev_err(&pdev->dev, "failed to parse dma-range\n");
> + return ret;
> + }
> } else {
> priv->busnr = pdev->id;
> }
> --
> 1.9.1
>
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