[U-Boot] [PATCH v3] Add single register pin controller driver

[Felix Brack]

Hi,

On 10.03.2017 04:55, James Balean wrote:
> This patch adds a pin controller driver supporting devices using a single configuration register per pin.
> 
> Signed-off-by: Felix Brack <fb at ltec.ch>

Remove this "Signed-off-by" tag as I neither made nor tested these
modifications. Furthermore it might not be good idea to name your
modifications to my patch "v3 ..." as this too could make people belief
I'm the originator or co-author of your modifications. What if I fix a
bug in my v2 patch? Should I then increase from v2 to v4?
Don't just 'hijack' a patch. Better add your comments, modification
requests, bug reports and explanations to the v2 thread of this patch as
I already suggested to you.

Felix

> [james at balean.com.au: changed .set_state_simple operation to .set_state]
> Signed-off-by: James Balean <james at balean.com.au>
> ---
>  drivers/pinctrl/Kconfig          |  10 +++
>  drivers/pinctrl/Makefile         |   1 +
>  drivers/pinctrl/pinctrl-single.c | 141 +++++++++++++++++++++++++++++++++++++++
>  3 files changed, 152 insertions(+)
>  create mode 100644 drivers/pinctrl/pinctrl-single.c
> 
> diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
> index efcb4c0..a2b9212 100644
> --- a/drivers/pinctrl/Kconfig
> +++ b/drivers/pinctrl/Kconfig
> @@ -175,6 +175,16 @@ config PIC32_PINCTRL
>  	  by a device tree node which contains both GPIO defintion and pin control
>  	  functions.
>  
> +config PINCTRL_SINGLE
> +	bool "Single register pin-control and pin-multiplex driver"
> +	depends on PINCTRL_FULL || SPL_PINCTRL_FULL
> +	help
> +	  This enables pinctrl driver for systems using a single register for
> +	  pin configuration and multiplexing. TI's AM335X SoCs are examples of
> +	  such systems.
> +	  Depending on the platform make sure to also enable OF_TRANSLATE and
> +	  eventually SPL_OF_TRANSLATE to get correct address translations.
> +
>  endif
>  
>  source "drivers/pinctrl/meson/Kconfig"
> diff --git a/drivers/pinctrl/Makefile b/drivers/pinctrl/Makefile
> index 512112a..f148f94 100644
> --- a/drivers/pinctrl/Makefile
> +++ b/drivers/pinctrl/Makefile
> @@ -16,3 +16,4 @@ obj-$(CONFIG_PIC32_PINCTRL)	+= pinctrl_pic32.o
>  obj-$(CONFIG_PINCTRL_EXYNOS)	+= exynos/
>  obj-$(CONFIG_PINCTRL_MESON)	+= meson/
>  obj-$(CONFIG_PINCTRL_MVEBU)	+= mvebu/
> +obj-$(CONFIG_PINCTRL_SINGLE)	+= pinctrl-single.o
> diff --git a/drivers/pinctrl/pinctrl-single.c b/drivers/pinctrl/pinctrl-single.c
> new file mode 100644
> index 0000000..a5b4d75
> --- /dev/null
> +++ b/drivers/pinctrl/pinctrl-single.c
> @@ -0,0 +1,141 @@
> +/*
> + * Copyright (C) EETS GmbH, 2017, Felix Brack <f.brack at eets.ch>
> + *
> + * SPDX-License-Identifier:	GPL-2.0+
> + */
> +
> +#include <common.h>
> +#include <dm/device.h>
> +#include <dm/pinctrl.h>
> +#include <libfdt.h>
> +#include <asm/io.h>
> +
> +DECLARE_GLOBAL_DATA_PTR;
> +
> +struct single_pdata {
> +	fdt_addr_t base;	/* first configuration register */
> +	int offset;		/* index of last configuration register */
> +	u32 mask;		/* configuration-value mask bits */
> +	int width;		/* configuration register bit width */
> +};
> +
> +struct single_fdt_pin_cfg {
> +	fdt32_t reg;		/* configuration register offset */
> +	fdt32_t val;		/* configuration register value */
> +};
> +
> +/**
> + * single_configure_pins() - Configure pins based on FDT data
> + *
> + * @dev: Pointer to single pin configuration device which is the parent of
> + *       the pins node holding the pin configuration data.
> + * @pins: Pointer to the first element of an array of register/value pairs
> + *        of type 'struct single_fdt_pin_cfg'. Each such pair describes the
> + *        the pin to be configured and the value to be used for configuration.
> + *        This pointer points to a 'pinctrl-single,pins' property in the
> + *        device-tree.
> + * @size: Size of the 'pins' array in bytes.
> + *        The number of register/value pairs in the 'pins' array therefore
> + *        equals to 'size / sizeof(struct single_fdt_pin_cfg)'.
> + */
> +static int single_configure_pins(struct udevice *dev,
> +				 const struct single_fdt_pin_cfg *pins,
> +				 int size)
> +{
> +	struct single_pdata *pdata = dev->platdata;
> +	int count = size / sizeof(struct single_fdt_pin_cfg);
> +	int n, reg;
> +	u32 val;
> +
> +	for (n = 0; n < count; n++) {
> +		reg = fdt32_to_cpu(pins->reg);
> +		if ((reg < 0) || (reg > pdata->offset)) {
> +			dev_dbg(dev, "  invalid register offset 0x%08x\n", reg);
> +			pins++;
> +			continue;
> +		}
> +		reg += pdata->base;
> +		switch (pdata->width) {
> +		case 32:
> +			val = readl(reg) & ~pdata->mask;
> +			val |= fdt32_to_cpu(pins->val) & pdata->mask;
> +			writel(val, reg);
> +			dev_dbg(dev, "  reg/val 0x%08x/0x%08x\n",
> +				reg, val);
> +			break;
> +		default:
> +			dev_warn(dev, "unsupported register width %i\n",
> +				 pdata->width);
> +		}
> +		pins++;
> +	}
> +	return 0;
> +}
> +
> +static int single_set_state(struct udevice *dev, struct udevice *config)
> +{
> +	const void *fdt = gd->fdt_blob;
> +	const struct single_fdt_pin_cfg *prop;
> +	int len;
> +
> +	prop = fdt_getprop(fdt, config->of_offset, "pinctrl-single,pins", &len);
> +	if (prop) {
> +		dev_dbg(dev, "configuring pins for %s\n", config->name);
> +		if (len % sizeof(struct single_fdt_pin_cfg)) {
> +			dev_dbg(dev, "  invalid pin configuration in fdt\n");
> +			return -FDT_ERR_BADSTRUCTURE;
> +		}
> +		single_configure_pins(dev, prop, len);
> +		len = 0;
> +	}
> +
> +	return len;
> +}
> +
> +static int single_ofdata_to_platdata(struct udevice *dev)
> +{
> +	fdt_addr_t addr;
> +	u32 of_reg[2];
> +	int res;
> +	struct single_pdata *pdata = dev->platdata;
> +
> +	pdata->width = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
> +				      "pinctrl-single,register-width", 0);
> +
> +	res = fdtdec_get_int_array(gd->fdt_blob, dev->of_offset,
> +				   "reg", of_reg, 2);
> +	if (res)
> +		return res;
> +	pdata->offset = of_reg[1] - pdata->width / 8;
> +
> +	addr = dev_get_addr(dev);
> +	if (addr == FDT_ADDR_T_NONE) {
> +		dev_dbg(dev, "no valid base register address\n");
> +		return -EINVAL;
> +	}
> +	pdata->base = addr;
> +
> +	pdata->mask = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
> +				     "pinctrl-single,function-mask",
> +				     0xffffffff);
> +	return 0;
> +}
> +
> +const struct pinctrl_ops single_pinctrl_ops = {
> +	.set_state = single_set_state,
> +};
> +
> +static const struct udevice_id single_pinctrl_match[] = {
> +	{ .compatible = "pinctrl-single" },
> +	{ /* sentinel */ }
> +};
> +
> +U_BOOT_DRIVER(single_pinctrl) = {
> +	.name = "single-pinctrl",
> +	.id = UCLASS_PINCTRL,
> +	.of_match = single_pinctrl_match,
> +	.ops = &single_pinctrl_ops,
> +	.flags = DM_FLAG_PRE_RELOC,
> +	.platdata_auto_alloc_size = sizeof(struct single_pdata),
> +	.ofdata_to_platdata = single_ofdata_to_platdata,
> +};
>