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- /*
- * Generic driver for memory-mapped GPIO controllers.
- *
- * Copyright 2008 MontaVista Software, Inc.
- * Copyright 2008,2010 Anton Vorontsov <cbouatmailru@gmail.com>
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License as published by the
- * Free Software Foundation; either version 2 of the License, or (at your
- * option) any later version.
- *
- * ....``.```~~~~````.`.`.`.`.```````'',,,.........`````......`.......
- * ...`` ```````..
- * ..The simplest form of a GPIO controller that the driver supports is``
- * `.just a single "data" register, where GPIO state can be read and/or `
- * `,..written. ,,..``~~~~ .....``.`.`.~~.```.`.........``````.```````
- * `````````
- ___
- _/~~|___/~| . ```~~~~~~ ___/___\___ ,~.`.`.`.`````.~~...,,,,...
- __________|~$@~~~ %~ /o*o*o*o*o*o\ .. Implementing such a GPIO .
- o ` ~~~~\___/~~~~ ` controller in FPGA is ,.`
- `....trivial..'~`.```.```
- * ```````
- * .```````~~~~`..`.``.``.
- * . The driver supports `... ,..```.`~~~```````````````....````.``,,
- * . big-endian notation, just`. .. A bit more sophisticated controllers ,
- * . register the device with -be`. .with a pair of set/clear-bit registers ,
- * `.. suffix. ```~~`````....`.` . affecting the data register and the .`
- * ``.`.``...``` ```.. output pins are also supported.`
- * ^^ `````.`````````.,``~``~``~~``````
- * . ^^
- * ,..`.`.`...````````````......`.`.`.`.`.`..`.`.`..
- * .. The expectation is that in at least some cases . ,-~~~-,
- * .this will be used with roll-your-own ASIC/FPGA .` \ /
- * .logic in Verilog or VHDL. ~~~`````````..`````~~` \ /
- * ..````````......``````````` \o_
- * |
- * ^^ / \
- *
- * ...`````~~`.....``.`..........``````.`.``.```........``.
- * ` 8, 16, 32 and 64 bits registers are supported, and``.
- * . the number of GPIOs is determined by the width of ~
- * .. the registers. ,............```.`.`..`.`.~~~.`.`.`~
- * `.......````.```
- */
- #include <linux/init.h>
- #include <linux/err.h>
- #include <linux/bug.h>
- #include <linux/kernel.h>
- #include <linux/module.h>
- #include <linux/spinlock.h>
- #include <linux/compiler.h>
- #include <linux/types.h>
- #include <linux/errno.h>
- #include <linux/log2.h>
- #include <linux/ioport.h>
- #include <linux/io.h>
- #include <linux/gpio/driver.h>
- #include <linux/slab.h>
- #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)
- {
- writeb(data, reg);
- }
- static unsigned long bgpio_read8(void __iomem *reg)
- {
- return readb(reg);
- }
- static void bgpio_write16(void __iomem *reg, unsigned long data)
- {
- writew(data, reg);
- }
- static unsigned long bgpio_read16(void __iomem *reg)
- {
- return readw(reg);
- }
- static void bgpio_write32(void __iomem *reg, unsigned long data)
- {
- writel(data, reg);
- }
- static unsigned long bgpio_read32(void __iomem *reg)
- {
- return readl(reg);
- }
- #if BITS_PER_LONG >= 64
- static void bgpio_write64(void __iomem *reg, unsigned long data)
- {
- writeq(data, reg);
- }
- static unsigned long bgpio_read64(void __iomem *reg)
- {
- return readq(reg);
- }
- #endif /* BITS_PER_LONG >= 64 */
- static void bgpio_write16be(void __iomem *reg, unsigned long data)
- {
- iowrite16be(data, reg);
- }
- static unsigned long bgpio_read16be(void __iomem *reg)
- {
- return ioread16be(reg);
- }
- static void bgpio_write32be(void __iomem *reg, unsigned long data)
- {
- iowrite32be(data, reg);
- }
- static unsigned long bgpio_read32be(void __iomem *reg)
- {
- return ioread32be(reg);
- }
- static unsigned long bgpio_pin2mask(struct gpio_chip *gc, unsigned int pin)
- {
- return BIT(pin);
- }
- static unsigned long bgpio_pin2mask_be(struct gpio_chip *gc,
- unsigned int pin)
- {
- return BIT(gc->bgpio_bits - 1 - pin);
- }
- static int bgpio_get_set(struct gpio_chip *gc, unsigned int gpio)
- {
- unsigned long pinmask = gc->pin2mask(gc, gpio);
- if (gc->bgpio_dir & pinmask)
- return !!(gc->read_reg(gc->reg_set) & pinmask);
- else
- return !!(gc->read_reg(gc->reg_dat) & pinmask);
- }
- static int bgpio_get(struct gpio_chip *gc, unsigned int gpio)
- {
- return !!(gc->read_reg(gc->reg_dat) & gc->pin2mask(gc, gpio));
- }
- static void bgpio_set_none(struct gpio_chip *gc, unsigned int gpio, int val)
- {
- }
- static void bgpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
- {
- unsigned long mask = gc->pin2mask(gc, gpio);
- unsigned long flags;
- spin_lock_irqsave(&gc->bgpio_lock, flags);
- if (val)
- gc->bgpio_data |= mask;
- else
- gc->bgpio_data &= ~mask;
- gc->write_reg(gc->reg_dat, gc->bgpio_data);
- spin_unlock_irqrestore(&gc->bgpio_lock, flags);
- }
- static void bgpio_set_with_clear(struct gpio_chip *gc, unsigned int gpio,
- int val)
- {
- unsigned long mask = gc->pin2mask(gc, gpio);
- if (val)
- gc->write_reg(gc->reg_set, mask);
- else
- gc->write_reg(gc->reg_clr, mask);
- }
- static void bgpio_set_set(struct gpio_chip *gc, unsigned int gpio, int val)
- {
- unsigned long mask = gc->pin2mask(gc, gpio);
- unsigned long flags;
- spin_lock_irqsave(&gc->bgpio_lock, flags);
- if (val)
- gc->bgpio_data |= mask;
- else
- gc->bgpio_data &= ~mask;
- gc->write_reg(gc->reg_set, gc->bgpio_data);
- spin_unlock_irqrestore(&gc->bgpio_lock, flags);
- }
- static void bgpio_multiple_get_masks(struct gpio_chip *gc,
- unsigned long *mask, unsigned long *bits,
- unsigned long *set_mask,
- unsigned long *clear_mask)
- {
- int i;
- *set_mask = 0;
- *clear_mask = 0;
- for (i = 0; i < gc->bgpio_bits; i++) {
- if (*mask == 0)
- break;
- if (__test_and_clear_bit(i, mask)) {
- if (test_bit(i, bits))
- *set_mask |= gc->pin2mask(gc, i);
- else
- *clear_mask |= gc->pin2mask(gc, i);
- }
- }
- }
- static void bgpio_set_multiple_single_reg(struct gpio_chip *gc,
- unsigned long *mask,
- unsigned long *bits,
- void __iomem *reg)
- {
- unsigned long flags;
- unsigned long set_mask, clear_mask;
- spin_lock_irqsave(&gc->bgpio_lock, flags);
- bgpio_multiple_get_masks(gc, mask, bits, &set_mask, &clear_mask);
- gc->bgpio_data |= set_mask;
- gc->bgpio_data &= ~clear_mask;
- gc->write_reg(reg, gc->bgpio_data);
- spin_unlock_irqrestore(&gc->bgpio_lock, flags);
- }
- static void bgpio_set_multiple(struct gpio_chip *gc, unsigned long *mask,
- unsigned long *bits)
- {
- bgpio_set_multiple_single_reg(gc, mask, bits, gc->reg_dat);
- }
- static void bgpio_set_multiple_set(struct gpio_chip *gc, unsigned long *mask,
- unsigned long *bits)
- {
- bgpio_set_multiple_single_reg(gc, mask, bits, gc->reg_set);
- }
- static void bgpio_set_multiple_with_clear(struct gpio_chip *gc,
- unsigned long *mask,
- unsigned long *bits)
- {
- unsigned long set_mask, clear_mask;
- bgpio_multiple_get_masks(gc, mask, bits, &set_mask, &clear_mask);
- if (set_mask)
- gc->write_reg(gc->reg_set, set_mask);
- if (clear_mask)
- gc->write_reg(gc->reg_clr, clear_mask);
- }
- static int bgpio_simple_dir_in(struct gpio_chip *gc, unsigned int gpio)
- {
- return 0;
- }
- static int bgpio_dir_out_err(struct gpio_chip *gc, unsigned int gpio,
- int val)
- {
- return -EINVAL;
- }
- static int bgpio_simple_dir_out(struct gpio_chip *gc, unsigned int gpio,
- int val)
- {
- gc->set(gc, gpio, val);
- return 0;
- }
- static int bgpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
- {
- unsigned long flags;
- spin_lock_irqsave(&gc->bgpio_lock, flags);
- gc->bgpio_dir &= ~gc->pin2mask(gc, gpio);
- gc->write_reg(gc->reg_dir, gc->bgpio_dir);
- spin_unlock_irqrestore(&gc->bgpio_lock, flags);
- return 0;
- }
- static int bgpio_get_dir(struct gpio_chip *gc, unsigned int gpio)
- {
- /* Return 0 if output, 1 of input */
- return !(gc->read_reg(gc->reg_dir) & gc->pin2mask(gc, gpio));
- }
- static int bgpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
- {
- unsigned long flags;
- gc->set(gc, gpio, val);
- spin_lock_irqsave(&gc->bgpio_lock, flags);
- gc->bgpio_dir |= gc->pin2mask(gc, gpio);
- gc->write_reg(gc->reg_dir, gc->bgpio_dir);
- spin_unlock_irqrestore(&gc->bgpio_lock, flags);
- return 0;
- }
- static int bgpio_dir_in_inv(struct gpio_chip *gc, unsigned int gpio)
- {
- unsigned long flags;
- spin_lock_irqsave(&gc->bgpio_lock, flags);
- gc->bgpio_dir |= gc->pin2mask(gc, gpio);
- gc->write_reg(gc->reg_dir, gc->bgpio_dir);
- spin_unlock_irqrestore(&gc->bgpio_lock, flags);
- return 0;
- }
- static int bgpio_dir_out_inv(struct gpio_chip *gc, unsigned int gpio, int val)
- {
- unsigned long flags;
- gc->set(gc, gpio, val);
- spin_lock_irqsave(&gc->bgpio_lock, flags);
- gc->bgpio_dir &= ~gc->pin2mask(gc, gpio);
- gc->write_reg(gc->reg_dir, gc->bgpio_dir);
- spin_unlock_irqrestore(&gc->bgpio_lock, flags);
- return 0;
- }
- static int bgpio_get_dir_inv(struct gpio_chip *gc, unsigned int gpio)
- {
- /* Return 0 if output, 1 if input */
- return !!(gc->read_reg(gc->reg_dir) & gc->pin2mask(gc, gpio));
- }
- static int bgpio_setup_accessors(struct device *dev,
- struct gpio_chip *gc,
- bool bit_be,
- bool byte_be)
- {
- switch (gc->bgpio_bits) {
- case 8:
- gc->read_reg = bgpio_read8;
- gc->write_reg = bgpio_write8;
- break;
- case 16:
- if (byte_be) {
- gc->read_reg = bgpio_read16be;
- gc->write_reg = bgpio_write16be;
- } else {
- gc->read_reg = bgpio_read16;
- gc->write_reg = bgpio_write16;
- }
- break;
- case 32:
- if (byte_be) {
- gc->read_reg = bgpio_read32be;
- gc->write_reg = bgpio_write32be;
- } else {
- gc->read_reg = bgpio_read32;
- gc->write_reg = bgpio_write32;
- }
- break;
- #if BITS_PER_LONG >= 64
- case 64:
- if (byte_be) {
- dev_err(dev,
- "64 bit big endian byte order unsupported\n");
- return -EINVAL;
- } else {
- gc->read_reg = bgpio_read64;
- gc->write_reg = bgpio_write64;
- }
- break;
- #endif /* BITS_PER_LONG >= 64 */
- default:
- dev_err(dev, "unsupported data width %u bits\n", gc->bgpio_bits);
- return -EINVAL;
- }
- gc->pin2mask = bit_be ? bgpio_pin2mask_be : bgpio_pin2mask;
- return 0;
- }
- /*
- * Create the device and allocate the resources. For setting GPIO's there are
- * three supported configurations:
- *
- * - single input/output register resource (named "dat").
- * - set/clear pair (named "set" and "clr").
- * - single output register resource and single input resource ("set" and
- * dat").
- *
- * For the single output register, this drives a 1 by setting a bit and a zero
- * by clearing a bit. For the set clr pair, this drives a 1 by setting a bit
- * in the set register and clears it by setting a bit in the clear register.
- * The configuration is detected by which resources are present.
- *
- * For setting the GPIO direction, there are three supported configurations:
- *
- * - simple bidirection GPIO that requires no configuration.
- * - an output direction register (named "dirout") where a 1 bit
- * indicates the GPIO is an output.
- * - an input direction register (named "dirin") where a 1 bit indicates
- * the GPIO is an input.
- */
- static int bgpio_setup_io(struct gpio_chip *gc,
- void __iomem *dat,
- void __iomem *set,
- void __iomem *clr,
- unsigned long flags)
- {
- gc->reg_dat = dat;
- if (!gc->reg_dat)
- return -EINVAL;
- if (set && clr) {
- gc->reg_set = set;
- gc->reg_clr = clr;
- gc->set = bgpio_set_with_clear;
- gc->set_multiple = bgpio_set_multiple_with_clear;
- } else if (set && !clr) {
- gc->reg_set = set;
- gc->set = bgpio_set_set;
- gc->set_multiple = bgpio_set_multiple_set;
- } else if (flags & BGPIOF_NO_OUTPUT) {
- gc->set = bgpio_set_none;
- gc->set_multiple = NULL;
- } else {
- gc->set = bgpio_set;
- gc->set_multiple = bgpio_set_multiple;
- }
- if (!(flags & BGPIOF_UNREADABLE_REG_SET) &&
- (flags & BGPIOF_READ_OUTPUT_REG_SET))
- gc->get = bgpio_get_set;
- else
- gc->get = bgpio_get;
- return 0;
- }
- static int bgpio_setup_direction(struct gpio_chip *gc,
- void __iomem *dirout,
- void __iomem *dirin,
- unsigned long flags)
- {
- if (dirout && dirin) {
- return -EINVAL;
- } else if (dirout) {
- gc->reg_dir = dirout;
- gc->direction_output = bgpio_dir_out;
- gc->direction_input = bgpio_dir_in;
- gc->get_direction = bgpio_get_dir;
- } else if (dirin) {
- gc->reg_dir = dirin;
- gc->direction_output = bgpio_dir_out_inv;
- gc->direction_input = bgpio_dir_in_inv;
- gc->get_direction = bgpio_get_dir_inv;
- } else {
- if (flags & BGPIOF_NO_OUTPUT)
- gc->direction_output = bgpio_dir_out_err;
- else
- gc->direction_output = bgpio_simple_dir_out;
- gc->direction_input = bgpio_simple_dir_in;
- }
- return 0;
- }
- static int bgpio_request(struct gpio_chip *chip, unsigned gpio_pin)
- {
- if (gpio_pin < chip->ngpio)
- return 0;
- return -EINVAL;
- }
- int bgpio_init(struct gpio_chip *gc, struct device *dev,
- unsigned long sz, void __iomem *dat, void __iomem *set,
- void __iomem *clr, void __iomem *dirout, void __iomem *dirin,
- unsigned long flags)
- {
- int ret;
- if (!is_power_of_2(sz))
- return -EINVAL;
- gc->bgpio_bits = sz * 8;
- if (gc->bgpio_bits > BITS_PER_LONG)
- return -EINVAL;
- spin_lock_init(&gc->bgpio_lock);
- gc->parent = dev;
- gc->label = dev_name(dev);
- gc->base = -1;
- gc->ngpio = gc->bgpio_bits;
- gc->request = bgpio_request;
- ret = bgpio_setup_io(gc, dat, set, clr, flags);
- if (ret)
- return ret;
- ret = bgpio_setup_accessors(dev, gc, flags & BGPIOF_BIG_ENDIAN,
- flags & BGPIOF_BIG_ENDIAN_BYTE_ORDER);
- if (ret)
- return ret;
- ret = bgpio_setup_direction(gc, dirout, dirin, flags);
- if (ret)
- return ret;
- gc->bgpio_data = gc->read_reg(gc->reg_dat);
- if (gc->set == bgpio_set_set &&
- !(flags & BGPIOF_UNREADABLE_REG_SET))
- gc->bgpio_data = gc->read_reg(gc->reg_set);
- if (gc->reg_dir && !(flags & BGPIOF_UNREADABLE_REG_DIR))
- gc->bgpio_dir = gc->read_reg(gc->reg_dir);
- return ret;
- }
- EXPORT_SYMBOL_GPL(bgpio_init);
- #if IS_ENABLED(CONFIG_GPIO_GENERIC_PLATFORM)
- static void __iomem *bgpio_map(struct platform_device *pdev,
- const char *name,
- resource_size_t sane_sz)
- {
- struct resource *r;
- resource_size_t sz;
- r = platform_get_resource_byname(pdev, IORESOURCE_MEM, name);
- if (!r)
- return NULL;
- sz = resource_size(r);
- if (sz != sane_sz)
- return IOMEM_ERR_PTR(-EINVAL);
- return devm_ioremap_resource(&pdev->dev, r);
- }
- #ifdef CONFIG_OF
- static const struct of_device_id bgpio_of_match[] = {
- { .compatible = "brcm,bcm6345-gpio" },
- { .compatible = "wd,mbl-gpio" },
- { }
- };
- MODULE_DEVICE_TABLE(of, bgpio_of_match);
- static struct bgpio_pdata *bgpio_parse_dt(struct platform_device *pdev,
- unsigned long *flags)
- {
- struct bgpio_pdata *pdata;
- if (!of_match_device(bgpio_of_match, &pdev->dev))
- return NULL;
- pdata = devm_kzalloc(&pdev->dev, sizeof(struct bgpio_pdata),
- GFP_KERNEL);
- if (!pdata)
- return ERR_PTR(-ENOMEM);
- pdata->base = -1;
- if (of_device_is_big_endian(pdev->dev.of_node))
- *flags |= BGPIOF_BIG_ENDIAN_BYTE_ORDER;
- if (of_property_read_bool(pdev->dev.of_node, "no-output"))
- *flags |= BGPIOF_NO_OUTPUT;
- 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;
- struct resource *r;
- void __iomem *dat;
- void __iomem *set;
- void __iomem *clr;
- void __iomem *dirout;
- void __iomem *dirin;
- unsigned long sz;
- unsigned long flags = 0;
- int err;
- struct gpio_chip *gc;
- 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)
- return -EINVAL;
- sz = resource_size(r);
- dat = bgpio_map(pdev, "dat", sz);
- if (IS_ERR(dat))
- return PTR_ERR(dat);
- set = bgpio_map(pdev, "set", sz);
- if (IS_ERR(set))
- return PTR_ERR(set);
- clr = bgpio_map(pdev, "clr", sz);
- if (IS_ERR(clr))
- return PTR_ERR(clr);
- dirout = bgpio_map(pdev, "dirout", sz);
- if (IS_ERR(dirout))
- return PTR_ERR(dirout);
- dirin = bgpio_map(pdev, "dirin", sz);
- if (IS_ERR(dirin))
- return PTR_ERR(dirin);
- gc = devm_kzalloc(&pdev->dev, sizeof(*gc), GFP_KERNEL);
- if (!gc)
- return -ENOMEM;
- err = bgpio_init(gc, dev, sz, dat, set, clr, dirout, dirin, flags);
- if (err)
- return err;
- if (pdata) {
- if (pdata->label)
- gc->label = pdata->label;
- gc->base = pdata->base;
- if (pdata->ngpio > 0)
- gc->ngpio = pdata->ngpio;
- }
- platform_set_drvdata(pdev, gc);
- return devm_gpiochip_add_data(&pdev->dev, gc, NULL);
- }
- static const struct platform_device_id bgpio_id_table[] = {
- {
- .name = "basic-mmio-gpio",
- .driver_data = 0,
- }, {
- .name = "basic-mmio-gpio-be",
- .driver_data = BGPIOF_BIG_ENDIAN,
- },
- { }
- };
- 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,
- };
- module_platform_driver(bgpio_driver);
- #endif /* CONFIG_GPIO_GENERIC_PLATFORM */
- MODULE_DESCRIPTION("Driver for basic memory-mapped GPIO controllers");
- MODULE_AUTHOR("Anton Vorontsov <cbouatmailru@gmail.com>");
- MODULE_LICENSE("GPL");
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