diff options
Diffstat (limited to 'drivers/gpio/gpio-creg-snps.c')
| -rw-r--r-- | drivers/gpio/gpio-creg-snps.c | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-creg-snps.c b/drivers/gpio/gpio-creg-snps.c new file mode 100644 index 0000000000..4968232f70 --- /dev/null +++ b/drivers/gpio/gpio-creg-snps.c @@ -0,0 +1,189 @@ +// SPDX-License-Identifier: GPL-2.0+ +// +// Synopsys CREG (Control REGisters) GPIO driver +// +// Copyright (C) 2018 Synopsys +// Author: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com> + +#include <linux/gpio/driver.h> +#include <linux/io.h> +#include <linux/of.h> +#include <linux/platform_device.h> + +#define MAX_GPIO 32 + +struct creg_layout { + u8 ngpio; + u8 shift[MAX_GPIO]; + u8 on[MAX_GPIO]; + u8 off[MAX_GPIO]; + u8 bit_per_gpio[MAX_GPIO]; +}; + +struct creg_gpio { + struct gpio_chip gc; + void __iomem *regs; + spinlock_t lock; + const struct creg_layout *layout; +}; + +static void creg_gpio_set(struct gpio_chip *gc, unsigned int offset, int val) +{ + struct creg_gpio *hcg = gpiochip_get_data(gc); + const struct creg_layout *layout = hcg->layout; + u32 reg, reg_shift, value; + unsigned long flags; + int i; + + value = val ? hcg->layout->on[offset] : hcg->layout->off[offset]; + + reg_shift = layout->shift[offset]; + for (i = 0; i < offset; i++) + reg_shift += layout->bit_per_gpio[i] + layout->shift[i]; + + spin_lock_irqsave(&hcg->lock, flags); + reg = readl(hcg->regs); + reg &= ~(GENMASK(layout->bit_per_gpio[i] - 1, 0) << reg_shift); + reg |= (value << reg_shift); + writel(reg, hcg->regs); + spin_unlock_irqrestore(&hcg->lock, flags); +} + +static int creg_gpio_dir_out(struct gpio_chip *gc, unsigned int offset, int val) +{ + creg_gpio_set(gc, offset, val); + + return 0; +} + +static int creg_gpio_validate_pg(struct device *dev, struct creg_gpio *hcg, + int i) +{ + const struct creg_layout *layout = hcg->layout; + + if (layout->bit_per_gpio[i] < 1 || layout->bit_per_gpio[i] > 8) + return -EINVAL; + + /* Check that on value fits its placeholder */ + if (GENMASK(31, layout->bit_per_gpio[i]) & layout->on[i]) + return -EINVAL; + + /* Check that off value fits its placeholder */ + if (GENMASK(31, layout->bit_per_gpio[i]) & layout->off[i]) + return -EINVAL; + + if (layout->on[i] == layout->off[i]) + return -EINVAL; + + return 0; +} + +static int creg_gpio_validate(struct device *dev, struct creg_gpio *hcg, + u32 ngpios) +{ + u32 reg_len = 0; + int i; + + if (hcg->layout->ngpio < 1 || hcg->layout->ngpio > MAX_GPIO) + return -EINVAL; + + if (ngpios < 1 || ngpios > hcg->layout->ngpio) { + dev_err(dev, "ngpios must be in [1:%u]\n", hcg->layout->ngpio); + return -EINVAL; + } + + for (i = 0; i < hcg->layout->ngpio; i++) { + if (creg_gpio_validate_pg(dev, hcg, i)) + return -EINVAL; + + reg_len += hcg->layout->shift[i] + hcg->layout->bit_per_gpio[i]; + } + + /* Check that we fit in 32 bit register */ + if (reg_len > 32) + return -EINVAL; + + return 0; +} + +static const struct creg_layout hsdk_cs_ctl = { + .ngpio = 10, + .shift = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }, + .off = { 2, 2, 2, 2, 2, 2, 2, 2, 2, 2 }, + .on = { 3, 3, 3, 3, 3, 3, 3, 3, 3, 3 }, + .bit_per_gpio = { 2, 2, 2, 2, 2, 2, 2, 2, 2, 2 } +}; + +static const struct creg_layout axs10x_flsh_cs_ctl = { + .ngpio = 1, + .shift = { 0 }, + .off = { 1 }, + .on = { 3 }, + .bit_per_gpio = { 2 } +}; + +static const struct of_device_id creg_gpio_ids[] = { + { + .compatible = "snps,creg-gpio-axs10x", + .data = &axs10x_flsh_cs_ctl + }, { + .compatible = "snps,creg-gpio-hsdk", + .data = &hsdk_cs_ctl + }, { /* sentinel */ } +}; + +static int creg_gpio_probe(struct platform_device *pdev) +{ + const struct of_device_id *match; + struct device *dev = &pdev->dev; + struct creg_gpio *hcg; + u32 ngpios; + int ret; + + hcg = devm_kzalloc(dev, sizeof(struct creg_gpio), GFP_KERNEL); + if (!hcg) + return -ENOMEM; + + hcg->regs = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(hcg->regs)) + return PTR_ERR(hcg->regs); + + match = of_match_node(creg_gpio_ids, pdev->dev.of_node); + hcg->layout = match->data; + if (!hcg->layout) + return -EINVAL; + + ret = of_property_read_u32(dev->of_node, "ngpios", &ngpios); + if (ret) + return ret; + + ret = creg_gpio_validate(dev, hcg, ngpios); + if (ret) + return ret; + + spin_lock_init(&hcg->lock); + + hcg->gc.parent = dev; + hcg->gc.label = dev_name(dev); + hcg->gc.base = -1; + hcg->gc.ngpio = ngpios; + hcg->gc.set = creg_gpio_set; + hcg->gc.direction_output = creg_gpio_dir_out; + + ret = devm_gpiochip_add_data(dev, &hcg->gc, hcg); + if (ret) + return ret; + + dev_info(dev, "GPIO controller with %d gpios probed\n", ngpios); + + return 0; +} + +static struct platform_driver creg_gpio_snps_driver = { + .driver = { + .name = "snps-creg-gpio", + .of_match_table = creg_gpio_ids, + }, + .probe = creg_gpio_probe, +}; +builtin_platform_driver(creg_gpio_snps_driver); |