On 11/05/2013 05:55 PM, Alan Tull wrote:
From: Jamie Iles <jamie@xxxxxxxxxxxxx> The Synopsys DesignWare block is used in some ARM devices (picoxcell) and can be configured to provide multiple banks of GPIO pins. v5: - handle sparse bank population correctly v3: - depend on rather than select IRQ_DOMAIN - split IRQ support into a separate patch v2: - use Rob Herring's irqdomain in generic irq chip patches - use reg property to indicate bank index - support irqs on both edges based on LinusW's u300 driver
Alan, thanks for reposting this. I haven't reviewed one of the earlier versions, so some of my comments may be referring to already answered questions.
Cc: Grant Likely <grant.likely@xxxxxxxxxxxx> Cc: Linus Walleij <linus.walleij@xxxxxxxxxxxxxx> Acked-by: Rob Herring <rob.herring@xxxxxxxxxxx> Signed-off-by: Jamie Iles <jamie@xxxxxxxxxxxxx> --- .../devicetree/bindings/gpio/snps-dwapb-gpio.txt | 57 +++++++ drivers/gpio/Kconfig | 9 + drivers/gpio/Makefile | 1 + drivers/gpio/gpio-dwapb.c | 172 ++++++++++++++++++++ 4 files changed, 239 insertions(+) create mode 100644 Documentation/devicetree/bindings/gpio/snps-dwapb-gpio.txt create mode 100644 drivers/gpio/gpio-dwapb.c diff --git a/Documentation/devicetree/bindings/gpio/snps-dwapb-gpio.txt b/Documentation/devicetree/bindings/gpio/snps-dwapb-gpio.txt new file mode 100644 index 0000000..73adf37 --- /dev/null +++ b/Documentation/devicetree/bindings/gpio/snps-dwapb-gpio.txt @@ -0,0 +1,57 @@ +* Synopsys DesignWare APB GPIO controller + +Required properties: +- compatible : Should be "snps,dw-apb-gpio" +- reg : Address and length of the register set for the device + +The GPIO controller has a configurable number of banks, each of which are +represented as child nodes with the following properties: + +Required properties: +- compatible : "snps,dw-apb-gpio-bank"
The register names refer to "bank" as "port", the above compatible should also reflect this.
+- gpio-controller : Marks the device node as a gpio controller. +- #gpio-cells : Should be two. The first cell is the pin number and + the second cell is used to specify optional parameters (currently + unused). +- reg : The integer bank index of the bank, a single cell. +- nr-gpio : The number of pins in the bank, a single cell.
What about "nr-gpios" or "#gpios"? Also, this property should be optional, as it can also be read from DW APB GPIOs CONFIG[12] registers.
+Optional properties: +- interrupt-controller : The first bank may be configured to be an interrupt +controller. +- #interrupt-cells : Specifies the number of cells needed to encode an +interrupt. Shall be set to 2. The first cell defines the interrupt number, +the second encodes the triger flags encoded as described in +Documentation/devicetree/bindings/interrupts.txt +- interrupt-parent : The parent interrupt controller. +- interrupts : The interrupts to the parent controller raised when GPIOs +generate the interrupts. + +Example: + +gpio: gpio@20000 { + compatible = "snps,dw-apb-gpio"; + reg = <0x20000 0x1000>; + #address-cells = <1>; + #size-cells = <0>; + + banka: gpio-controller@0 { + compatible = "snps,dw-apb-gpio-bank"; + gpio-controller; + #gpio-cells = <2>; + nr-gpio = <8>; + reg = <0>; + interrupt-controller; + #interrupt-cells = <2>; + interrupt-parent = <&vic1>; + interrupts = <0 1 2 3 4 5 6 7>; + }; + + bankb: gpio-controller@1 { + compatible = "snps,dw-apb-gpio-bank"; + gpio-controller; + #gpio-cells = <2>; + nr-gpio = <8>; + reg = <1>; + }; +}; diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index b6ed304..c5e7868 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -121,6 +121,15 @@ config GPIO_GENERIC_PLATFORM help Say yes here to support basic platform_device memory-mapped GPIO controllers. +config GPIO_DWAPB + bool "Synopsys DesignWare APB GPIO driver" + select GPIO_GENERIC + select GENERIC_IRQ_CHIP + depends on OF_GPIO + help + Say Y or M here to build support for the Synopsys DesignWare APB + GPIO block. This requires device tree support.
I'd remove the comment about DT requirement, but leave the OF_GPIO dependency. If not now, we will remove DT dependency for sure later.
config GPIO_IT8761E tristate "IT8761E GPIO support" depends on X86 # unconditional access to IO space. diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index 98e23eb..8de041a 100644 --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile @@ -22,6 +22,7 @@ obj-$(CONFIG_GPIO_CS5535) += gpio-cs5535.o obj-$(CONFIG_GPIO_DA9052) += gpio-da9052.o obj-$(CONFIG_GPIO_DA9055) += gpio-da9055.o obj-$(CONFIG_ARCH_DAVINCI) += gpio-davinci.o +obj-$(CONFIG_GPIO_DWAPB) += gpio-dwapb.o obj-$(CONFIG_GPIO_EM) += gpio-em.o obj-$(CONFIG_GPIO_EP93XX) += gpio-ep93xx.o obj-$(CONFIG_GPIO_F7188X) += gpio-f7188x.o diff --git a/drivers/gpio/gpio-dwapb.c b/drivers/gpio/gpio-dwapb.c new file mode 100644 index 0000000..3a28697 --- /dev/null +++ b/drivers/gpio/gpio-dwapb.c @@ -0,0 +1,172 @@ +/* + * Copyright (c) 2011 Jamie Iles + * + * 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 + * published by the Free Software Foundation. + * + * All enquiries to support@xxxxxxxxxxxx + */ +#include <linux/init.h> +#include <linux/io.h> +#include <linux/ioport.h> +#include <linux/module.h> +#include <linux/basic_mmio_gpio.h>
alphabetical ordering
+#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/platform_device.h> + +struct dwapb_gpio; + +struct dwapb_gpio_bank {
Again, "bank" is "port".
+ struct bgpio_chip bgc; + unsigned int bank_idx; + bool is_registered; + struct dwapb_gpio *gpio; +}; + +struct dwapb_gpio { + struct device_node *of_node; + struct device *dev;
What about taking dev.of_node instead of the an extra of_node ptr?
+ void __iomem *regs; + struct dwapb_gpio_bank *banks; + unsigned int nr_banks;
ditto and for the following "banks", too.
+}; + +static unsigned int dwapb_gpio_nr_banks(struct device_node *of_node) +{ + unsigned int nr_banks = 0; + struct device_node *np; + + for_each_child_of_node(of_node, np) + ++nr_banks;
In general, I'd prefer a DT agnostic driver based on platform_data and DT parsing instead of using DT spread over the driver. Anyway, I don't want to stall this patches even further, so it can be cleaned up later.
+ return nr_banks; +} + +static int dwapb_gpio_add_bank(struct dwapb_gpio *gpio, + struct device_node *bank_np, + unsigned int offs) +{ + struct dwapb_gpio_bank *bank; + u32 bank_idx, ngpio; + int err; + + if (of_property_read_u32(bank_np, "reg", &bank_idx)) { + dev_err(gpio->dev, "invalid bank index for %s\n", + bank_np->full_name);
index > 3 are also "invalid", of_property_read_u32 fails if it is "missing".
+ return -EINVAL; + } + bank = &gpio->banks[offs]; + bank->gpio = gpio; + + if (of_property_read_u32(bank_np, "nr-gpio", &ngpio)) { + dev_err(gpio->dev, "failed to get number of gpios for %s\n", + bank_np->full_name); + return -EINVAL; + } + + bank->bank_idx = bank_idx; + err = bgpio_init(&bank->bgc, gpio->dev, 4, + gpio->regs + 0x50 + (bank_idx * 0x4), + gpio->regs + 0x00 + (bank_idx * 0xc), + NULL, gpio->regs + 0x04 + (bank_idx * 0xc), NULL,
#defines for the magic numbers above?
+ false); + if (err) { + dev_err(gpio->dev, "failed to init gpio chip for %s\n", + bank_np->full_name); + return err; + } + + bank->bgc.gc.ngpio = ngpio; + bank->bgc.gc.of_node = bank_np; + + err = gpiochip_add(&bank->bgc.gc); + if (err) + dev_err(gpio->dev, "failed to register gpiochip for %s\n", + bank_np->full_name); + else + bank->is_registered = true; + + return err; +} + +static void dwapb_gpio_unregister(struct dwapb_gpio *gpio) +{ + unsigned int m; + + for (m = 0; m < gpio->nr_banks; ++m) + if (gpio->banks[m].is_registered) + WARN_ON(gpiochip_remove(&gpio->banks[m].bgc.gc)); + of_node_put(gpio->of_node);
I may be wrong here, but platform_device_unregister will finally remove pdev and pdev->dev anyway. No need to put the node right before it.
+} + +static int __devinit dwapb_gpio_probe(struct platform_device *pdev) +{ + struct resource *res; + struct dwapb_gpio *gpio; + struct device_node *np; + int err; + unsigned int offs = 0; + + gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL); + if (!gpio) + return -ENOMEM; + gpio->dev = &pdev->dev; + + gpio->nr_banks = dwapb_gpio_nr_banks(pdev->dev.of_node); + if (!gpio->nr_banks) + return -EINVAL; + gpio->banks = devm_kzalloc(&pdev->dev, gpio->nr_banks * + sizeof(*gpio->banks), GFP_KERNEL); + if (!gpio->banks) + return -ENOMEM; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) { + dev_err(&pdev->dev, "failed to get iomem\n"); + return -ENXIO; + }
devm_ioremap below can deal with NULL resources. I suggest to remove the extra check and error message above, as devm_ioremap and friends will also print error messages.
+ gpio->regs = devm_ioremap(&pdev->dev, res->start, resource_size(res));
devm_ioremap_resource?
+ if (!gpio->regs) + return -ENOMEM; + + gpio->of_node = of_node_get(pdev->dev.of_node);
no need to of_node_get here, and of_node_put above.
+ for_each_child_of_node(pdev->dev.of_node, np) { + err = dwapb_gpio_add_bank(gpio, np, offs++); + if (err) + goto out_unregister; + } + platform_set_drvdata(pdev, gpio); + + return 0; + +out_unregister: + dwapb_gpio_unregister(gpio); + + return err; +} + +static const struct of_device_id dwapb_of_match_table[] = { + { .compatible = "snps,dw-apb-gpio" }, + { /* Sentinel */ } +}; + +static struct platform_driver dwapb_gpio_driver = { + .driver = { + .name = "gpio-dwapb", + .owner = THIS_MODULE, + .of_match_table = dwapb_of_match_table,
use of_match_ptr(dwapb_of_match_table) now, we will need it later. Sebastian
+ }, + .probe = dwapb_gpio_probe, +}; + +static int __init dwapb_gpio_init(void) +{ + return platform_driver_register(&dwapb_gpio_driver); +} +postcore_initcall(dwapb_gpio_init); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Jamie Iles"); +MODULE_DESCRIPTION("Synopsys DesignWare APB GPIO driver");
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