1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * GPIO interface for Intel Poulsbo SCH 4 * 5 * Copyright (c) 2010 CompuLab Ltd 6 * Author: Denis Turischev <denis@compulab.co.il> 7 */ 8 9 #include <linux/acpi.h> 10 #include <linux/errno.h> 11 #include <linux/gpio/driver.h> 12 #include <linux/io.h> 13 #include <linux/kernel.h> 14 #include <linux/module.h> 15 #include <linux/pci_ids.h> 16 #include <linux/platform_device.h> 17 18 #define GEN 0x00 19 #define GIO 0x04 20 #define GLV 0x08 21 22 struct sch_gpio { 23 struct gpio_chip chip; 24 spinlock_t lock; 25 unsigned short iobase; 26 unsigned short resume_base; 27 }; 28 29 static unsigned sch_gpio_offset(struct sch_gpio *sch, unsigned gpio, 30 unsigned reg) 31 { 32 unsigned base = 0; 33 34 if (gpio >= sch->resume_base) { 35 gpio -= sch->resume_base; 36 base += 0x20; 37 } 38 39 return base + reg + gpio / 8; 40 } 41 42 static unsigned sch_gpio_bit(struct sch_gpio *sch, unsigned gpio) 43 { 44 if (gpio >= sch->resume_base) 45 gpio -= sch->resume_base; 46 return gpio % 8; 47 } 48 49 static int sch_gpio_reg_get(struct sch_gpio *sch, unsigned gpio, unsigned reg) 50 { 51 unsigned short offset, bit; 52 u8 reg_val; 53 54 offset = sch_gpio_offset(sch, gpio, reg); 55 bit = sch_gpio_bit(sch, gpio); 56 57 reg_val = !!(inb(sch->iobase + offset) & BIT(bit)); 58 59 return reg_val; 60 } 61 62 static void sch_gpio_reg_set(struct sch_gpio *sch, unsigned gpio, unsigned reg, 63 int val) 64 { 65 unsigned short offset, bit; 66 u8 reg_val; 67 68 offset = sch_gpio_offset(sch, gpio, reg); 69 bit = sch_gpio_bit(sch, gpio); 70 71 reg_val = inb(sch->iobase + offset); 72 73 if (val) 74 outb(reg_val | BIT(bit), sch->iobase + offset); 75 else 76 outb((reg_val & ~BIT(bit)), sch->iobase + offset); 77 } 78 79 static int sch_gpio_direction_in(struct gpio_chip *gc, unsigned gpio_num) 80 { 81 struct sch_gpio *sch = gpiochip_get_data(gc); 82 83 spin_lock(&sch->lock); 84 sch_gpio_reg_set(sch, gpio_num, GIO, 1); 85 spin_unlock(&sch->lock); 86 return 0; 87 } 88 89 static int sch_gpio_get(struct gpio_chip *gc, unsigned gpio_num) 90 { 91 struct sch_gpio *sch = gpiochip_get_data(gc); 92 return sch_gpio_reg_get(sch, gpio_num, GLV); 93 } 94 95 static void sch_gpio_set(struct gpio_chip *gc, unsigned gpio_num, int val) 96 { 97 struct sch_gpio *sch = gpiochip_get_data(gc); 98 99 spin_lock(&sch->lock); 100 sch_gpio_reg_set(sch, gpio_num, GLV, val); 101 spin_unlock(&sch->lock); 102 } 103 104 static int sch_gpio_direction_out(struct gpio_chip *gc, unsigned gpio_num, 105 int val) 106 { 107 struct sch_gpio *sch = gpiochip_get_data(gc); 108 109 spin_lock(&sch->lock); 110 sch_gpio_reg_set(sch, gpio_num, GIO, 0); 111 spin_unlock(&sch->lock); 112 113 /* 114 * according to the datasheet, writing to the level register has no 115 * effect when GPIO is programmed as input. 116 * Actually the the level register is read-only when configured as input. 117 * Thus presetting the output level before switching to output is _NOT_ possible. 118 * Hence we set the level after configuring the GPIO as output. 119 * But we cannot prevent a short low pulse if direction is set to high 120 * and an external pull-up is connected. 121 */ 122 sch_gpio_set(gc, gpio_num, val); 123 return 0; 124 } 125 126 static int sch_gpio_get_direction(struct gpio_chip *gc, unsigned gpio_num) 127 { 128 struct sch_gpio *sch = gpiochip_get_data(gc); 129 130 return sch_gpio_reg_get(sch, gpio_num, GIO); 131 } 132 133 static const struct gpio_chip sch_gpio_chip = { 134 .label = "sch_gpio", 135 .owner = THIS_MODULE, 136 .direction_input = sch_gpio_direction_in, 137 .get = sch_gpio_get, 138 .direction_output = sch_gpio_direction_out, 139 .set = sch_gpio_set, 140 .get_direction = sch_gpio_get_direction, 141 }; 142 143 static int sch_gpio_probe(struct platform_device *pdev) 144 { 145 struct sch_gpio *sch; 146 struct resource *res; 147 148 sch = devm_kzalloc(&pdev->dev, sizeof(*sch), GFP_KERNEL); 149 if (!sch) 150 return -ENOMEM; 151 152 res = platform_get_resource(pdev, IORESOURCE_IO, 0); 153 if (!res) 154 return -EBUSY; 155 156 if (!devm_request_region(&pdev->dev, res->start, resource_size(res), 157 pdev->name)) 158 return -EBUSY; 159 160 spin_lock_init(&sch->lock); 161 sch->iobase = res->start; 162 sch->chip = sch_gpio_chip; 163 sch->chip.label = dev_name(&pdev->dev); 164 sch->chip.parent = &pdev->dev; 165 166 switch (pdev->id) { 167 case PCI_DEVICE_ID_INTEL_SCH_LPC: 168 sch->resume_base = 10; 169 sch->chip.ngpio = 14; 170 171 /* 172 * GPIO[6:0] enabled by default 173 * GPIO7 is configured by the CMC as SLPIOVR 174 * Enable GPIO[9:8] core powered gpios explicitly 175 */ 176 sch_gpio_reg_set(sch, 8, GEN, 1); 177 sch_gpio_reg_set(sch, 9, GEN, 1); 178 /* 179 * SUS_GPIO[2:0] enabled by default 180 * Enable SUS_GPIO3 resume powered gpio explicitly 181 */ 182 sch_gpio_reg_set(sch, 13, GEN, 1); 183 break; 184 185 case PCI_DEVICE_ID_INTEL_ITC_LPC: 186 sch->resume_base = 5; 187 sch->chip.ngpio = 14; 188 break; 189 190 case PCI_DEVICE_ID_INTEL_CENTERTON_ILB: 191 sch->resume_base = 21; 192 sch->chip.ngpio = 30; 193 break; 194 195 case PCI_DEVICE_ID_INTEL_QUARK_X1000_ILB: 196 sch->resume_base = 2; 197 sch->chip.ngpio = 8; 198 break; 199 200 default: 201 return -ENODEV; 202 } 203 204 platform_set_drvdata(pdev, sch); 205 206 return devm_gpiochip_add_data(&pdev->dev, &sch->chip, sch); 207 } 208 209 static struct platform_driver sch_gpio_driver = { 210 .driver = { 211 .name = "sch_gpio", 212 }, 213 .probe = sch_gpio_probe, 214 }; 215 216 module_platform_driver(sch_gpio_driver); 217 218 MODULE_AUTHOR("Denis Turischev <denis@compulab.co.il>"); 219 MODULE_DESCRIPTION("GPIO interface for Intel Poulsbo SCH"); 220 MODULE_LICENSE("GPL v2"); 221 MODULE_ALIAS("platform:sch_gpio"); 222