From: Álvaro Fernández Rojas <noltari@xxxxxxxxx> This patch adds support for defining memory-mapped GPIOs which provide a compatible interface for the existing generic-gpio driver. Signed-off-by: Álvaro Fernández Rojas <noltari@xxxxxxxxx> Signed-off-by: Christian Lamparter <chunkeey@xxxxxxxxxxxxxx> --- drivers/gpio/gpio-generic.c | 98 ++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 96 insertions(+), 2 deletions(-) diff --git a/drivers/gpio/gpio-generic.c b/drivers/gpio/gpio-generic.c index 6c1cb3b..129c3ba 100644 --- a/drivers/gpio/gpio-generic.c +++ b/drivers/gpio/gpio-generic.c @@ -61,6 +61,8 @@ o ` ~~~~\___/~~~~ ` controller in FPGA is ,.` #include <linux/bitops.h> #include <linux/platform_device.h> #include <linux/mod_devicetable.h> +#include <linux/of.h> +#include <linux/of_device.h> static void bgpio_write8(void __iomem *reg, unsigned long data) { @@ -569,6 +571,88 @@ static void __iomem *bgpio_map(struct platform_device *pdev, return devm_ioremap_resource(&pdev->dev, r); } +#ifdef CONFIG_OF +static int bgpio_basic_mmio_parse_dt(struct platform_device *pdev, + struct bgpio_pdata *pdata, + unsigned long *flags) +{ + struct device *dev = &pdev->dev; + int err; + + /* If ngpio property is not specified, of_property_read_u32 + * will return -EINVAL. In this case the number of GPIOs is + * automatically determined by the register width. Any + * other error of of_property_read_u32 is due bad data and + * needs to be dealt with. + */ + err = of_property_read_u32(dev->of_node, "ngpio", &pdata->ngpio); + if (err && err != -EINVAL) + return err; + + if (of_device_is_big_endian(dev->of_node)) + *flags |= BGPIOF_BIG_ENDIAN_BYTE_ORDER; + + if (of_property_read_bool(dev->of_node, "unreadable-reg-set")) + *flags |= BGPIOF_UNREADABLE_REG_SET; + + if (of_property_read_bool(dev->of_node, "unreadable-reg-dir")) + *flags |= BGPIOF_UNREADABLE_REG_DIR; + + if (of_property_read_bool(dev->of_node, "big-endian-byte-order")) + *flags |= BGPIOF_BIG_ENDIAN; + + if (of_property_read_bool(dev->of_node, "read-output-reg-set")) + *flags |= BGPIOF_READ_OUTPUT_REG_SET; + + if (of_property_read_bool(dev->of_node, "no-output")) + *flags |= BGPIOF_NO_OUTPUT; + return 0; +} + +#define ADD(_name, _func) { .compatible = _name, .data = _func } + +static const struct of_device_id bgpio_of_match[] = { + ADD("linux,gpio-mmio", bgpio_basic_mmio_parse_dt), + { } +}; +#undef ADD +MODULE_DEVICE_TABLE(of, bgpio_of_match); + +static struct bgpio_pdata *bgpio_parse_dt(struct platform_device *pdev, + unsigned long *flags) +{ + int (*parse_dt)(struct platform_device *, + struct bgpio_pdata *, unsigned long *); + const struct device_node *node = pdev->dev.of_node; + const struct of_device_id *of_id; + struct bgpio_pdata *pdata; + int err = -ENODEV; + + of_id = of_match_node(bgpio_of_match, node); + if (!of_id) + return NULL; + + pdata = devm_kzalloc(&pdev->dev, sizeof(struct bgpio_pdata), + GFP_KERNEL); + if (!pdata) + return ERR_PTR(-ENOMEM); + + parse_dt = of_id->data; + if (parse_dt) + err = parse_dt(pdev, pdata, flags); + if (err) + return ERR_PTR(err); + + return pdata; +} +#else +static struct bgpio_pdata *bgpio_parse_dt(struct platform_device *pdev, + unsigned long *flags) +{ + return NULL; +} +#endif /* CONFIG_OF */ + static int bgpio_pdev_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; @@ -579,10 +663,19 @@ static int bgpio_pdev_probe(struct platform_device *pdev) void __iomem *dirout; void __iomem *dirin; unsigned long sz; - unsigned long flags = pdev->id_entry->driver_data; + unsigned long flags = 0; int err; struct gpio_chip *gc; - struct bgpio_pdata *pdata = dev_get_platdata(dev); + struct bgpio_pdata *pdata; + + pdata = bgpio_parse_dt(pdev, &flags); + if (IS_ERR(pdata)) + return PTR_ERR(pdata); + + if (!pdata) { + pdata = dev_get_platdata(dev); + flags = pdev->id_entry->driver_data; + } r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dat"); if (!r) @@ -646,6 +739,7 @@ MODULE_DEVICE_TABLE(platform, bgpio_id_table); static struct platform_driver bgpio_driver = { .driver = { .name = "basic-mmio-gpio", + .of_match_table = of_match_ptr(bgpio_of_match), }, .id_table = bgpio_id_table, .probe = bgpio_pdev_probe, -- 2.8.1 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html