1 /* 2 * Driver core interface to the pinctrl subsystem. 3 * 4 * Copyright (C) 2012 ST-Ericsson SA 5 * Written on behalf of Linaro for ST-Ericsson 6 * Based on bits of regulator core, gpio core and clk core 7 * 8 * Author: Linus Walleij <linus.walleij@linaro.org> 9 * 10 * License terms: GNU General Public License (GPL) version 2 11 */ 12 13 #include <linux/device.h> 14 #include <linux/pinctrl/devinfo.h> 15 #include <linux/pinctrl/consumer.h> 16 #include <linux/slab.h> 17 18 /** 19 * pinctrl_bind_pins() - called by the device core before probe 20 * @dev: the device that is just about to probe 21 */ 22 int pinctrl_bind_pins(struct device *dev) 23 { 24 int ret; 25 26 dev->pins = devm_kzalloc(dev, sizeof(*(dev->pins)), GFP_KERNEL); 27 if (!dev->pins) 28 return -ENOMEM; 29 30 dev->pins->p = devm_pinctrl_get(dev); 31 if (IS_ERR(dev->pins->p)) { 32 dev_dbg(dev, "no pinctrl handle\n"); 33 ret = PTR_ERR(dev->pins->p); 34 goto cleanup_alloc; 35 } 36 37 dev->pins->default_state = pinctrl_lookup_state(dev->pins->p, 38 PINCTRL_STATE_DEFAULT); 39 if (IS_ERR(dev->pins->default_state)) { 40 dev_dbg(dev, "no default pinctrl state\n"); 41 ret = 0; 42 goto cleanup_get; 43 } 44 45 dev->pins->init_state = pinctrl_lookup_state(dev->pins->p, 46 PINCTRL_STATE_INIT); 47 if (IS_ERR(dev->pins->init_state)) { 48 /* Not supplying this state is perfectly legal */ 49 dev_dbg(dev, "no init pinctrl state\n"); 50 51 ret = pinctrl_select_state(dev->pins->p, 52 dev->pins->default_state); 53 } else { 54 ret = pinctrl_select_state(dev->pins->p, dev->pins->init_state); 55 } 56 57 if (ret) { 58 dev_dbg(dev, "failed to activate initial pinctrl state\n"); 59 goto cleanup_get; 60 } 61 62 #ifdef CONFIG_PM 63 /* 64 * If power management is enabled, we also look for the optional 65 * sleep and idle pin states, with semantics as defined in 66 * <linux/pinctrl/pinctrl-state.h> 67 */ 68 dev->pins->sleep_state = pinctrl_lookup_state(dev->pins->p, 69 PINCTRL_STATE_SLEEP); 70 if (IS_ERR(dev->pins->sleep_state)) 71 /* Not supplying this state is perfectly legal */ 72 dev_dbg(dev, "no sleep pinctrl state\n"); 73 74 dev->pins->idle_state = pinctrl_lookup_state(dev->pins->p, 75 PINCTRL_STATE_IDLE); 76 if (IS_ERR(dev->pins->idle_state)) 77 /* Not supplying this state is perfectly legal */ 78 dev_dbg(dev, "no idle pinctrl state\n"); 79 #endif 80 81 return 0; 82 83 /* 84 * If no pinctrl handle or default state was found for this device, 85 * let's explicitly free the pin container in the device, there is 86 * no point in keeping it around. 87 */ 88 cleanup_get: 89 devm_pinctrl_put(dev->pins->p); 90 cleanup_alloc: 91 devm_kfree(dev, dev->pins); 92 dev->pins = NULL; 93 94 /* Return deferrals */ 95 if (ret == -EPROBE_DEFER) 96 return ret; 97 /* Return serious errors */ 98 if (ret == -EINVAL) 99 return ret; 100 /* We ignore errors like -ENOENT meaning no pinctrl state */ 101 102 return 0; 103 } 104