mirror of
https://github.com/AsahiLinux/u-boot
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83d290c56f
When U-Boot started using SPDX tags we were among the early adopters and there weren't a lot of other examples to borrow from. So we picked the area of the file that usually had a full license text and replaced it with an appropriate SPDX-License-Identifier: entry. Since then, the Linux Kernel has adopted SPDX tags and they place it as the very first line in a file (except where shebangs are used, then it's second line) and with slightly different comment styles than us. In part due to community overlap, in part due to better tag visibility and in part for other minor reasons, switch over to that style. This commit changes all instances where we have a single declared license in the tag as both the before and after are identical in tag contents. There's also a few places where I found we did not have a tag and have introduced one. Signed-off-by: Tom Rini <trini@konsulko.com>
191 lines
4.2 KiB
C
191 lines
4.2 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* Take drivers/gpio/gpio-74x164.c as reference.
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*
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* 74Hx164 - Generic serial-in/parallel-out 8-bits shift register GPIO driver
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*
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* Copyright (C) 2016 Peng Fan <van.freenix@gmail.com>
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*
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*/
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#include <common.h>
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#include <errno.h>
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#include <dm.h>
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#include <fdtdec.h>
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#include <malloc.h>
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#include <asm/gpio.h>
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#include <asm/io.h>
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#include <dt-bindings/gpio/gpio.h>
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#include <spi.h>
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DECLARE_GLOBAL_DATA_PTR;
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/*
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* struct gen_74x164_chip - Data for 74Hx164
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*
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* @oe: OE pin
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* @nregs: number of registers
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* @buffer: buffer for chained chips
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*/
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#define GEN_74X164_NUMBER_GPIOS 8
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struct gen_74x164_priv {
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struct gpio_desc oe;
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u32 nregs;
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/*
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* Since the nregs are chained, every byte sent will make
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* the previous byte shift to the next register in the
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* chain. Thus, the first byte sent will end up in the last
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* register at the end of the transfer. So, to have a logical
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* numbering, store the bytes in reverse order.
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*/
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u8 *buffer;
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};
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static int gen_74x164_write_conf(struct udevice *dev)
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{
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struct gen_74x164_priv *priv = dev_get_priv(dev);
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int ret;
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ret = dm_spi_claim_bus(dev);
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if (ret)
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return ret;
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ret = dm_spi_xfer(dev, priv->nregs * 8, priv->buffer, NULL,
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SPI_XFER_BEGIN | SPI_XFER_END);
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dm_spi_release_bus(dev);
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return ret;
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}
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static int gen_74x164_get_value(struct udevice *dev, unsigned offset)
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{
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struct gen_74x164_priv *priv = dev_get_priv(dev);
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uint bank = priv->nregs - 1 - offset / 8;
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uint pin = offset % 8;
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return (priv->buffer[bank] >> pin) & 0x1;
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}
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static int gen_74x164_set_value(struct udevice *dev, unsigned offset,
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int value)
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{
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struct gen_74x164_priv *priv = dev_get_priv(dev);
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uint bank = priv->nregs - 1 - offset / 8;
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uint pin = offset % 8;
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int ret;
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if (value)
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priv->buffer[bank] |= 1 << pin;
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else
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priv->buffer[bank] &= ~(1 << pin);
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ret = gen_74x164_write_conf(dev);
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if (ret)
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return ret;
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return 0;
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}
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static int gen_74x164_direction_input(struct udevice *dev, unsigned offset)
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{
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return -ENOSYS;
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}
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static int gen_74x164_direction_output(struct udevice *dev, unsigned offset,
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int value)
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{
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return gen_74x164_set_value(dev, offset, value);
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}
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static int gen_74x164_get_function(struct udevice *dev, unsigned offset)
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{
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return GPIOF_OUTPUT;
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}
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static int gen_74x164_xlate(struct udevice *dev, struct gpio_desc *desc,
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struct ofnode_phandle_args *args)
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{
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desc->offset = args->args[0];
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desc->flags = args->args[1] & GPIO_ACTIVE_LOW ? GPIOD_ACTIVE_LOW : 0;
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return 0;
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}
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static const struct dm_gpio_ops gen_74x164_ops = {
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.direction_input = gen_74x164_direction_input,
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.direction_output = gen_74x164_direction_output,
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.get_value = gen_74x164_get_value,
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.set_value = gen_74x164_set_value,
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.get_function = gen_74x164_get_function,
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.xlate = gen_74x164_xlate,
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};
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static int gen_74x164_probe(struct udevice *dev)
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{
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struct gen_74x164_priv *priv = dev_get_priv(dev);
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struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
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char *str, name[32];
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int ret;
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const void *fdt = gd->fdt_blob;
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int node = dev_of_offset(dev);
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snprintf(name, sizeof(name), "%s_", dev->name);
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str = strdup(name);
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if (!str)
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return -ENOMEM;
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/*
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* See Linux kernel:
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* Documentation/devicetree/bindings/gpio/gpio-74x164.txt
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*/
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priv->nregs = fdtdec_get_int(fdt, node, "registers-number", 1);
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priv->buffer = calloc(priv->nregs, sizeof(u8));
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if (!priv->buffer) {
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ret = -ENOMEM;
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goto free_str;
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}
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ret = fdtdec_get_byte_array(fdt, node, "registers-default",
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priv->buffer, priv->nregs);
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if (ret)
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dev_dbg(dev, "No registers-default property\n");
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ret = gpio_request_by_name(dev, "oe-gpios", 0, &priv->oe,
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GPIOD_IS_OUT | GPIOD_IS_OUT_ACTIVE);
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if (ret) {
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dev_dbg(dev, "No oe-pins property\n");
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}
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uc_priv->bank_name = str;
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uc_priv->gpio_count = priv->nregs * 8;
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ret = gen_74x164_write_conf(dev);
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if (ret)
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goto free_buf;
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dev_dbg(dev, "%s is ready\n", dev->name);
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return 0;
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free_buf:
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free(priv->buffer);
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free_str:
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free(str);
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return ret;
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}
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static const struct udevice_id gen_74x164_ids[] = {
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{ .compatible = "fairchild,74hc595" },
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{ }
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};
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U_BOOT_DRIVER(74x164) = {
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.name = "74x164",
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.id = UCLASS_GPIO,
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.ops = &gen_74x164_ops,
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.probe = gen_74x164_probe,
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.priv_auto_alloc_size = sizeof(struct gen_74x164_priv),
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.of_match = gen_74x164_ids,
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};
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