1 /* 2 * Access to GPOs on TWL6040 chip 3 * 4 * Copyright (C) 2012 Texas Instruments, Inc. 5 * 6 * Authors: 7 * Sergio Aguirre <saaguirre@ti.com> 8 * Peter Ujfalusi <peter.ujfalusi@ti.com> 9 * 10 * This program is free software; you can redistribute it and/or modify 11 * it under the terms of the GNU General Public License as published by 12 * the Free Software Foundation; either version 2 of the License, or 13 * (at your option) any later version. 14 * 15 * This program is distributed in the hope that it will be useful, 16 * but WITHOUT ANY WARRANTY; without even the implied warranty of 17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 18 * GNU General Public License for more details. 19 * 20 * You should have received a copy of the GNU General Public License 21 * along with this program; if not, write to the Free Software 22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 23 */ 24 25 #include <linux/module.h> 26 #include <linux/init.h> 27 #include <linux/kthread.h> 28 #include <linux/irq.h> 29 #include <linux/gpio.h> 30 #include <linux/platform_device.h> 31 #include <linux/of.h> 32 33 #include <linux/mfd/twl6040.h> 34 35 static int twl6040gpo_get(struct gpio_chip *chip, unsigned offset) 36 { 37 struct twl6040 *twl6040 = dev_get_drvdata(chip->parent->parent); 38 int ret = 0; 39 40 ret = twl6040_reg_read(twl6040, TWL6040_REG_GPOCTL); 41 if (ret < 0) 42 return ret; 43 44 return (ret >> offset) & 1; 45 } 46 47 static int twl6040gpo_direction_out(struct gpio_chip *chip, unsigned offset, 48 int value) 49 { 50 /* This only drives GPOs, and can't change direction */ 51 return 0; 52 } 53 54 static void twl6040gpo_set(struct gpio_chip *chip, unsigned offset, int value) 55 { 56 struct twl6040 *twl6040 = dev_get_drvdata(chip->parent->parent); 57 int ret; 58 u8 gpoctl; 59 60 ret = twl6040_reg_read(twl6040, TWL6040_REG_GPOCTL); 61 if (ret < 0) 62 return; 63 64 if (value) 65 gpoctl = ret | (1 << offset); 66 else 67 gpoctl = ret & ~(1 << offset); 68 69 twl6040_reg_write(twl6040, TWL6040_REG_GPOCTL, gpoctl); 70 } 71 72 static struct gpio_chip twl6040gpo_chip = { 73 .label = "twl6040", 74 .owner = THIS_MODULE, 75 .get = twl6040gpo_get, 76 .direction_output = twl6040gpo_direction_out, 77 .set = twl6040gpo_set, 78 .can_sleep = true, 79 }; 80 81 /*----------------------------------------------------------------------*/ 82 83 static int gpo_twl6040_probe(struct platform_device *pdev) 84 { 85 struct device *twl6040_core_dev = pdev->dev.parent; 86 struct twl6040 *twl6040 = dev_get_drvdata(twl6040_core_dev); 87 int ret; 88 89 twl6040gpo_chip.base = -1; 90 91 if (twl6040_get_revid(twl6040) < TWL6041_REV_ES2_0) 92 twl6040gpo_chip.ngpio = 3; /* twl6040 have 3 GPO */ 93 else 94 twl6040gpo_chip.ngpio = 1; /* twl6041 have 1 GPO */ 95 96 twl6040gpo_chip.parent = &pdev->dev; 97 #ifdef CONFIG_OF_GPIO 98 twl6040gpo_chip.of_node = twl6040_core_dev->of_node; 99 #endif 100 101 ret = devm_gpiochip_add_data(&pdev->dev, &twl6040gpo_chip, NULL); 102 if (ret < 0) { 103 dev_err(&pdev->dev, "could not register gpiochip, %d\n", ret); 104 twl6040gpo_chip.ngpio = 0; 105 } 106 107 return ret; 108 } 109 110 /* Note: this hardware lives inside an I2C-based multi-function device. */ 111 MODULE_ALIAS("platform:twl6040-gpo"); 112 113 static struct platform_driver gpo_twl6040_driver = { 114 .driver = { 115 .name = "twl6040-gpo", 116 }, 117 .probe = gpo_twl6040_probe, 118 }; 119 120 module_platform_driver(gpo_twl6040_driver); 121 122 MODULE_AUTHOR("Texas Instruments, Inc."); 123 MODULE_DESCRIPTION("GPO interface for TWL6040"); 124 MODULE_LICENSE("GPL"); 125