1d2912cb1SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only
26596e59eSSudip Mukherjee /*
36596e59eSSudip Mukherjee * GPIO driver for Exar XR17V35X chip
46596e59eSSudip Mukherjee *
56596e59eSSudip Mukherjee * Copyright (C) 2015 Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>
66596e59eSSudip Mukherjee */
71bfaf129SBartosz Golaszewski
86596e59eSSudip Mukherjee #include <linux/bitops.h>
96596e59eSSudip Mukherjee #include <linux/device.h>
106596e59eSSudip Mukherjee #include <linux/gpio/driver.h>
1126ced453SBartosz Golaszewski #include <linux/idr.h>
126596e59eSSudip Mukherjee #include <linux/init.h>
136596e59eSSudip Mukherjee #include <linux/kernel.h>
146596e59eSSudip Mukherjee #include <linux/module.h>
156596e59eSSudip Mukherjee #include <linux/pci.h>
166596e59eSSudip Mukherjee #include <linux/platform_device.h>
1736fb7218SBartosz Golaszewski #include <linux/regmap.h>
186596e59eSSudip Mukherjee
196596e59eSSudip Mukherjee #define EXAR_OFFSET_MPIOLVL_LO 0x90
206596e59eSSudip Mukherjee #define EXAR_OFFSET_MPIOSEL_LO 0x93
216596e59eSSudip Mukherjee #define EXAR_OFFSET_MPIOLVL_HI 0x96
226596e59eSSudip Mukherjee #define EXAR_OFFSET_MPIOSEL_HI 0x99
236596e59eSSudip Mukherjee
245134272fSQingtao Cao /*
255134272fSQingtao Cao * The Device Configuration and UART Configuration Registers
265134272fSQingtao Cao * for each UART channel take 1KB of memory address space.
275134272fSQingtao Cao */
285134272fSQingtao Cao #define EXAR_UART_CHANNEL_SIZE 0x400
295134272fSQingtao Cao
306596e59eSSudip Mukherjee #define DRIVER_NAME "gpio_exar"
316596e59eSSudip Mukherjee
326596e59eSSudip Mukherjee static DEFINE_IDA(ida_index);
336596e59eSSudip Mukherjee
346596e59eSSudip Mukherjee struct exar_gpio_chip {
356596e59eSSudip Mukherjee struct gpio_chip gpio_chip;
3636fb7218SBartosz Golaszewski struct regmap *regmap;
376596e59eSSudip Mukherjee int index;
386596e59eSSudip Mukherjee char name[20];
39380b1e2fSJan Kiszka unsigned int first_pin;
405134272fSQingtao Cao /*
415134272fSQingtao Cao * The offset to the cascaded device's (if existing)
425134272fSQingtao Cao * Device Configuration Registers.
435134272fSQingtao Cao */
445134272fSQingtao Cao unsigned int cascaded_offset;
456596e59eSSudip Mukherjee };
466596e59eSSudip Mukherjee
47696868d0SBartosz Golaszewski static unsigned int
exar_offset_to_sel_addr(struct exar_gpio_chip * exar_gpio,unsigned int offset)48696868d0SBartosz Golaszewski exar_offset_to_sel_addr(struct exar_gpio_chip *exar_gpio, unsigned int offset)
49696868d0SBartosz Golaszewski {
505134272fSQingtao Cao unsigned int pin = exar_gpio->first_pin + (offset % 16);
515134272fSQingtao Cao unsigned int cascaded = offset / 16;
525134272fSQingtao Cao unsigned int addr = pin / 8 ? EXAR_OFFSET_MPIOSEL_HI : EXAR_OFFSET_MPIOSEL_LO;
535134272fSQingtao Cao
545134272fSQingtao Cao return addr + (cascaded ? exar_gpio->cascaded_offset : 0);
55696868d0SBartosz Golaszewski }
56696868d0SBartosz Golaszewski
57696868d0SBartosz Golaszewski static unsigned int
exar_offset_to_lvl_addr(struct exar_gpio_chip * exar_gpio,unsigned int offset)58696868d0SBartosz Golaszewski exar_offset_to_lvl_addr(struct exar_gpio_chip *exar_gpio, unsigned int offset)
59696868d0SBartosz Golaszewski {
605134272fSQingtao Cao unsigned int pin = exar_gpio->first_pin + (offset % 16);
615134272fSQingtao Cao unsigned int cascaded = offset / 16;
625134272fSQingtao Cao unsigned int addr = pin / 8 ? EXAR_OFFSET_MPIOLVL_HI : EXAR_OFFSET_MPIOLVL_LO;
635134272fSQingtao Cao
645134272fSQingtao Cao return addr + (cascaded ? exar_gpio->cascaded_offset : 0);
65696868d0SBartosz Golaszewski }
66696868d0SBartosz Golaszewski
67696868d0SBartosz Golaszewski static unsigned int
exar_offset_to_bit(struct exar_gpio_chip * exar_gpio,unsigned int offset)68696868d0SBartosz Golaszewski exar_offset_to_bit(struct exar_gpio_chip *exar_gpio, unsigned int offset)
69696868d0SBartosz Golaszewski {
705134272fSQingtao Cao unsigned int pin = exar_gpio->first_pin + (offset % 16);
715134272fSQingtao Cao
725134272fSQingtao Cao return pin % 8;
73696868d0SBartosz Golaszewski }
74696868d0SBartosz Golaszewski
exar_get_direction(struct gpio_chip * chip,unsigned int offset)756596e59eSSudip Mukherjee static int exar_get_direction(struct gpio_chip *chip, unsigned int offset)
766596e59eSSudip Mukherjee {
77380b1e2fSJan Kiszka struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip);
78696868d0SBartosz Golaszewski unsigned int addr = exar_offset_to_sel_addr(exar_gpio, offset);
79696868d0SBartosz Golaszewski unsigned int bit = exar_offset_to_bit(exar_gpio, offset);
806596e59eSSudip Mukherjee
8136fb7218SBartosz Golaszewski if (regmap_test_bits(exar_gpio->regmap, addr, BIT(bit)))
82e42615ecSMatti Vaittinen return GPIO_LINE_DIRECTION_IN;
83e42615ecSMatti Vaittinen
84e42615ecSMatti Vaittinen return GPIO_LINE_DIRECTION_OUT;
856596e59eSSudip Mukherjee }
866596e59eSSudip Mukherjee
exar_get_value(struct gpio_chip * chip,unsigned int offset)876596e59eSSudip Mukherjee static int exar_get_value(struct gpio_chip *chip, unsigned int offset)
886596e59eSSudip Mukherjee {
89380b1e2fSJan Kiszka struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip);
90696868d0SBartosz Golaszewski unsigned int addr = exar_offset_to_lvl_addr(exar_gpio, offset);
91696868d0SBartosz Golaszewski unsigned int bit = exar_offset_to_bit(exar_gpio, offset);
926596e59eSSudip Mukherjee
9336fb7218SBartosz Golaszewski return !!(regmap_test_bits(exar_gpio->regmap, addr, BIT(bit)));
946596e59eSSudip Mukherjee }
956596e59eSSudip Mukherjee
exar_set_value(struct gpio_chip * chip,unsigned int offset,int value)966596e59eSSudip Mukherjee static void exar_set_value(struct gpio_chip *chip, unsigned int offset,
976596e59eSSudip Mukherjee int value)
986596e59eSSudip Mukherjee {
99380b1e2fSJan Kiszka struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip);
100696868d0SBartosz Golaszewski unsigned int addr = exar_offset_to_lvl_addr(exar_gpio, offset);
101696868d0SBartosz Golaszewski unsigned int bit = exar_offset_to_bit(exar_gpio, offset);
1026596e59eSSudip Mukherjee
10336fb7218SBartosz Golaszewski if (value)
10436fb7218SBartosz Golaszewski regmap_set_bits(exar_gpio->regmap, addr, BIT(bit));
10536fb7218SBartosz Golaszewski else
10636fb7218SBartosz Golaszewski regmap_clear_bits(exar_gpio->regmap, addr, BIT(bit));
1076596e59eSSudip Mukherjee }
1086596e59eSSudip Mukherjee
exar_direction_output(struct gpio_chip * chip,unsigned int offset,int value)109eddeae07SAxel Lin static int exar_direction_output(struct gpio_chip *chip, unsigned int offset,
110eddeae07SAxel Lin int value)
111eddeae07SAxel Lin {
11236fb7218SBartosz Golaszewski struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip);
11336fb7218SBartosz Golaszewski unsigned int addr = exar_offset_to_sel_addr(exar_gpio, offset);
11436fb7218SBartosz Golaszewski unsigned int bit = exar_offset_to_bit(exar_gpio, offset);
11536fb7218SBartosz Golaszewski
116eddeae07SAxel Lin exar_set_value(chip, offset, value);
11736fb7218SBartosz Golaszewski regmap_clear_bits(exar_gpio->regmap, addr, BIT(bit));
11836fb7218SBartosz Golaszewski
11936fb7218SBartosz Golaszewski return 0;
120eddeae07SAxel Lin }
121eddeae07SAxel Lin
exar_direction_input(struct gpio_chip * chip,unsigned int offset)122eddeae07SAxel Lin static int exar_direction_input(struct gpio_chip *chip, unsigned int offset)
123eddeae07SAxel Lin {
12436fb7218SBartosz Golaszewski struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip);
12536fb7218SBartosz Golaszewski unsigned int addr = exar_offset_to_sel_addr(exar_gpio, offset);
12636fb7218SBartosz Golaszewski unsigned int bit = exar_offset_to_bit(exar_gpio, offset);
12736fb7218SBartosz Golaszewski
12836fb7218SBartosz Golaszewski regmap_set_bits(exar_gpio->regmap, addr, BIT(bit));
12936fb7218SBartosz Golaszewski
13036fb7218SBartosz Golaszewski return 0;
131eddeae07SAxel Lin }
132eddeae07SAxel Lin
exar_devm_ida_free(void * data)1335300ebb6SBartosz Golaszewski static void exar_devm_ida_free(void *data)
1345300ebb6SBartosz Golaszewski {
1355300ebb6SBartosz Golaszewski struct exar_gpio_chip *exar_gpio = data;
1365300ebb6SBartosz Golaszewski
1375300ebb6SBartosz Golaszewski ida_free(&ida_index, exar_gpio->index);
1385300ebb6SBartosz Golaszewski }
1395300ebb6SBartosz Golaszewski
14036fb7218SBartosz Golaszewski static const struct regmap_config exar_regmap_config = {
14136fb7218SBartosz Golaszewski .name = "exar-gpio",
14236fb7218SBartosz Golaszewski .reg_bits = 16,
14336fb7218SBartosz Golaszewski .val_bits = 8,
144*b4e83d36SAndy Shevchenko .io_port = true,
14536fb7218SBartosz Golaszewski };
14636fb7218SBartosz Golaszewski
gpio_exar_probe(struct platform_device * pdev)1476596e59eSSudip Mukherjee static int gpio_exar_probe(struct platform_device *pdev)
1486596e59eSSudip Mukherjee {
1490c2c7e13SBartosz Golaszewski struct device *dev = &pdev->dev;
1500c2c7e13SBartosz Golaszewski struct pci_dev *pcidev = to_pci_dev(dev->parent);
1516596e59eSSudip Mukherjee struct exar_gpio_chip *exar_gpio;
152380b1e2fSJan Kiszka u32 first_pin, ngpios;
1536596e59eSSudip Mukherjee void __iomem *p;
1546596e59eSSudip Mukherjee int index, ret;
1556596e59eSSudip Mukherjee
1566596e59eSSudip Mukherjee /*
1578847f5f9SJan Kiszka * The UART driver must have mapped region 0 prior to registering this
1588847f5f9SJan Kiszka * device - use it.
1596596e59eSSudip Mukherjee */
1608847f5f9SJan Kiszka p = pcim_iomap_table(pcidev)[0];
1616596e59eSSudip Mukherjee if (!p)
1626596e59eSSudip Mukherjee return -ENOMEM;
1636596e59eSSudip Mukherjee
1640c2c7e13SBartosz Golaszewski ret = device_property_read_u32(dev, "exar,first-pin", &first_pin);
165380b1e2fSJan Kiszka if (ret)
166380b1e2fSJan Kiszka return ret;
167380b1e2fSJan Kiszka
1680c2c7e13SBartosz Golaszewski ret = device_property_read_u32(dev, "ngpios", &ngpios);
169380b1e2fSJan Kiszka if (ret)
170380b1e2fSJan Kiszka return ret;
171380b1e2fSJan Kiszka
1720c2c7e13SBartosz Golaszewski exar_gpio = devm_kzalloc(dev, sizeof(*exar_gpio), GFP_KERNEL);
1736596e59eSSudip Mukherjee if (!exar_gpio)
1746596e59eSSudip Mukherjee return -ENOMEM;
1756596e59eSSudip Mukherjee
17636fb7218SBartosz Golaszewski /*
1775134272fSQingtao Cao * If cascaded, secondary xr17v354 or xr17v358 have the same amount
1785134272fSQingtao Cao * of MPIOs as their primaries and the last 4 bits of the primary's
1795134272fSQingtao Cao * PCI Device ID is the number of its UART channels.
1805134272fSQingtao Cao */
1815134272fSQingtao Cao if (pcidev->device & GENMASK(15, 12)) {
1825134272fSQingtao Cao ngpios += ngpios;
1835134272fSQingtao Cao exar_gpio->cascaded_offset = (pcidev->device & GENMASK(3, 0)) *
1845134272fSQingtao Cao EXAR_UART_CHANNEL_SIZE;
1855134272fSQingtao Cao }
1865134272fSQingtao Cao
1875134272fSQingtao Cao /*
18836fb7218SBartosz Golaszewski * We don't need to check the return values of mmio regmap operations (unless
18936fb7218SBartosz Golaszewski * the regmap has a clock attached which is not the case here).
19036fb7218SBartosz Golaszewski */
19136fb7218SBartosz Golaszewski exar_gpio->regmap = devm_regmap_init_mmio(dev, p, &exar_regmap_config);
19236fb7218SBartosz Golaszewski if (IS_ERR(exar_gpio->regmap))
19336fb7218SBartosz Golaszewski return PTR_ERR(exar_gpio->regmap);
1946596e59eSSudip Mukherjee
1958e27c2aeSBartosz Golaszewski index = ida_alloc(&ida_index, GFP_KERNEL);
19636fb7218SBartosz Golaszewski if (index < 0)
19736fb7218SBartosz Golaszewski return index;
1986596e59eSSudip Mukherjee
1995300ebb6SBartosz Golaszewski ret = devm_add_action_or_reset(dev, exar_devm_ida_free, exar_gpio);
2005300ebb6SBartosz Golaszewski if (ret)
2015300ebb6SBartosz Golaszewski return ret;
2025300ebb6SBartosz Golaszewski
2036596e59eSSudip Mukherjee sprintf(exar_gpio->name, "exar_gpio%d", index);
2046596e59eSSudip Mukherjee exar_gpio->gpio_chip.label = exar_gpio->name;
2050c2c7e13SBartosz Golaszewski exar_gpio->gpio_chip.parent = dev;
2066596e59eSSudip Mukherjee exar_gpio->gpio_chip.direction_output = exar_direction_output;
2076596e59eSSudip Mukherjee exar_gpio->gpio_chip.direction_input = exar_direction_input;
2086596e59eSSudip Mukherjee exar_gpio->gpio_chip.get_direction = exar_get_direction;
2096596e59eSSudip Mukherjee exar_gpio->gpio_chip.get = exar_get_value;
2106596e59eSSudip Mukherjee exar_gpio->gpio_chip.set = exar_set_value;
2116596e59eSSudip Mukherjee exar_gpio->gpio_chip.base = -1;
212380b1e2fSJan Kiszka exar_gpio->gpio_chip.ngpio = ngpios;
2136596e59eSSudip Mukherjee exar_gpio->index = index;
214380b1e2fSJan Kiszka exar_gpio->first_pin = first_pin;
2156596e59eSSudip Mukherjee
2160c2c7e13SBartosz Golaszewski ret = devm_gpiochip_add_data(dev, &exar_gpio->gpio_chip, exar_gpio);
2176596e59eSSudip Mukherjee if (ret)
2185300ebb6SBartosz Golaszewski return ret;
2196596e59eSSudip Mukherjee
2206596e59eSSudip Mukherjee return 0;
2216596e59eSSudip Mukherjee }
2226596e59eSSudip Mukherjee
2236596e59eSSudip Mukherjee static struct platform_driver gpio_exar_driver = {
2246596e59eSSudip Mukherjee .probe = gpio_exar_probe,
2256596e59eSSudip Mukherjee .driver = {
2266596e59eSSudip Mukherjee .name = DRIVER_NAME,
2276596e59eSSudip Mukherjee },
2286596e59eSSudip Mukherjee };
2296596e59eSSudip Mukherjee
2306596e59eSSudip Mukherjee module_platform_driver(gpio_exar_driver);
2316596e59eSSudip Mukherjee
2326596e59eSSudip Mukherjee MODULE_ALIAS("platform:" DRIVER_NAME);
2336596e59eSSudip Mukherjee MODULE_DESCRIPTION("Exar GPIO driver");
2346596e59eSSudip Mukherjee MODULE_AUTHOR("Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>");
2356596e59eSSudip Mukherjee MODULE_LICENSE("GPL");
236