203 lines
5.1 KiB
C
203 lines
5.1 KiB
C
/*
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* Designware GPIO support functions
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*
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* Copyright (C) 2012 Altera
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <common.h>
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#include <errno.h>
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#include <io.h>
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#include <gpio.h>
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#include <init.h>
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#include <linux/err.h>
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#define DW_GPIO_DR 0x0
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#define DW_GPIO_DDR 0x4
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#define DW_GPIO_EXT 0x50
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#define DW_GPIO_CONFIG2 0x70
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#define DW_GPIO_CONFIG1 0x74
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#define DW_GPIO_CONFIG2_WIDTH(val, port) (((val) >> ((port) * 4) & 0x1f) + 1)
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#define DW_GPIO_CONFIG1_NPORTS(val) (((val) >> 2 & 0x3) + 1)
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struct dw_gpio {
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void __iomem *regs;
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};
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struct dw_gpio_instance {
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struct dw_gpio *parent;
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struct gpio_chip chip;
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u32 gpio_state; /* GPIO state shadow register */
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u32 gpio_dir; /* GPIO direction shadow register */
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};
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static inline struct dw_gpio_instance *to_dw_gpio(struct gpio_chip *gc)
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{
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return container_of(gc, struct dw_gpio_instance, chip);
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}
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static int dw_gpio_get(struct gpio_chip *gc, unsigned offset)
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{
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struct dw_gpio_instance *chip = to_dw_gpio(gc);
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struct dw_gpio *parent = chip->parent;
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return (readl(parent->regs + DW_GPIO_EXT) >> offset) & 1;
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}
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static void dw_gpio_set(struct gpio_chip *gc, unsigned offset, int value)
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{
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struct dw_gpio_instance *chip = to_dw_gpio(gc);
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struct dw_gpio *parent = chip->parent;
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u32 data_reg;
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data_reg = readl(parent->regs + DW_GPIO_DR);
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data_reg = (data_reg & ~(1<<offset)) | (value << offset);
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writel(data_reg, parent->regs + DW_GPIO_DR);
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}
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static int dw_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
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{
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struct dw_gpio_instance *chip = to_dw_gpio(gc);
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struct dw_gpio *parent = chip->parent;
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u32 gpio_ddr;
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/* Set pin as input, assumes software controlled IP */
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gpio_ddr = readl(parent->regs + DW_GPIO_DDR);
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gpio_ddr &= ~(1 << offset);
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writel(gpio_ddr, parent->regs + DW_GPIO_DDR);
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return 0;
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}
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static int dw_gpio_direction_output(struct gpio_chip *gc,
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unsigned offset, int value)
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{
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struct dw_gpio_instance *chip = to_dw_gpio(gc);
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struct dw_gpio *parent = chip->parent;
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u32 gpio_ddr;
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dw_gpio_set(gc, offset, value);
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/* Set pin as output, assumes software controlled IP */
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gpio_ddr = readl(parent->regs + DW_GPIO_DDR);
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gpio_ddr |= (1 << offset);
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writel(gpio_ddr, parent->regs + DW_GPIO_DDR);
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return 0;
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}
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static int dw_gpio_get_direction(struct gpio_chip *gc, unsigned offset)
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{
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struct dw_gpio_instance *chip = to_dw_gpio(gc);
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struct dw_gpio *parent = chip->parent;
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return (readl(parent->regs + DW_GPIO_DDR) & (1 << offset)) ?
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GPIOF_DIR_OUT : GPIOF_DIR_IN;
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}
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static struct gpio_ops dw_gpio_ops = {
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.direction_input = dw_gpio_direction_input,
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.direction_output = dw_gpio_direction_output,
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.get_direction = dw_gpio_get_direction,
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.get = dw_gpio_get,
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.set = dw_gpio_set,
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};
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static int dw_gpio_add_port(struct device_d *dev, struct device_node *node,
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struct dw_gpio *parent)
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{
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struct dw_gpio_instance *chip;
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uint32_t config1, config2;
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int ngpio, ret;
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chip = xzalloc(sizeof(*chip));
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chip->chip.ops = &dw_gpio_ops;
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if (dev->id < 0)
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chip->chip.base = DEVICE_ID_DYNAMIC;
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else
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chip->chip.base = dev->id * 32;
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config2 = readl(parent->regs + DW_GPIO_CONFIG2);
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config1 = readl(parent->regs + DW_GPIO_CONFIG1);
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ngpio = DW_GPIO_CONFIG2_WIDTH(config2, 0);
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if (DW_GPIO_CONFIG1_NPORTS(config1) > 1)
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dev_info(dev, "ignoring ports B-D\n");
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chip->parent = parent;
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chip->chip.ngpio = ngpio;
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chip->chip.dev = add_generic_device("dw-port", DEVICE_ID_DYNAMIC, NULL,
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dev->resource[0].start,
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resource_size(&dev->resource[0]),
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IORESOURCE_MEM, NULL);
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if (!chip->chip.dev) {
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dev_err(dev, "unable to add device\n");
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return -ENODEV;
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}
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chip->chip.dev->device_node = node;
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ret = gpiochip_add(&chip->chip);
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if (ret)
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return ret;
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dev_dbg(chip->chip.dev, "probed gpiochip with %d gpios, base %d\n",
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chip->chip.ngpio, chip->chip.base);
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return 0;
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}
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static int dw_gpio_probe(struct device_d *dev)
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{
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struct resource *iores;
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struct dw_gpio *gpio;
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struct device_node *node;
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gpio = xzalloc(sizeof(*gpio));
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iores = dev_request_mem_resource(dev, 0);
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if (IS_ERR(iores))
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return PTR_ERR(iores);
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gpio->regs = IOMEM(iores->start);
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for_each_child_of_node(dev->device_node, node)
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dw_gpio_add_port(dev, node, gpio);
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return 0;
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}
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static __maybe_unused struct of_device_id dwgpio_match[] = {
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{
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.compatible = "snps,dw-apb-gpio",
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}, {
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/* sentinel */
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},
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};
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static struct driver_d dwgpio_driver = {
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.name = "dw-apb-gpio",
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.probe = dw_gpio_probe,
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.of_compatible = DRV_OF_COMPAT(dwgpio_match),
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};
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static int __init dwgpio_init(void)
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{
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return platform_driver_register(&dwgpio_driver);
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}
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core_initcall(dwgpio_init);
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