1 /* 2 * Core driver for the generic pin config portions of the pin control subsystem 3 * 4 * Copyright (C) 2011 ST-Ericsson SA 5 * Written on behalf of Linaro for ST-Ericsson 6 * 7 * Author: Linus Walleij <linus.walleij@linaro.org> 8 * 9 * License terms: GNU General Public License (GPL) version 2 10 */ 11 12 #define pr_fmt(fmt) "generic pinconfig core: " fmt 13 14 #include <linux/kernel.h> 15 #include <linux/module.h> 16 #include <linux/init.h> 17 #include <linux/device.h> 18 #include <linux/slab.h> 19 #include <linux/debugfs.h> 20 #include <linux/seq_file.h> 21 #include <linux/pinctrl/pinctrl.h> 22 #include <linux/pinctrl/pinconf.h> 23 #include <linux/pinctrl/pinconf-generic.h> 24 #include <linux/of.h> 25 #include "core.h" 26 #include "pinconf.h" 27 28 #ifdef CONFIG_DEBUG_FS 29 30 struct pin_config_item { 31 const enum pin_config_param param; 32 const char * const display; 33 const char * const format; 34 }; 35 36 #define PCONFDUMP(a, b, c) { .param = a, .display = b, .format = c } 37 38 static struct pin_config_item conf_items[] = { 39 PCONFDUMP(PIN_CONFIG_BIAS_DISABLE, "input bias disabled", NULL), 40 PCONFDUMP(PIN_CONFIG_BIAS_HIGH_IMPEDANCE, "input bias high impedance", NULL), 41 PCONFDUMP(PIN_CONFIG_BIAS_BUS_HOLD, "input bias bus hold", NULL), 42 PCONFDUMP(PIN_CONFIG_BIAS_PULL_UP, "input bias pull up", NULL), 43 PCONFDUMP(PIN_CONFIG_BIAS_PULL_DOWN, "input bias pull down", NULL), 44 PCONFDUMP(PIN_CONFIG_BIAS_PULL_PIN_DEFAULT, 45 "input bias pull to pin specific state", NULL), 46 PCONFDUMP(PIN_CONFIG_DRIVE_PUSH_PULL, "output drive push pull", NULL), 47 PCONFDUMP(PIN_CONFIG_DRIVE_OPEN_DRAIN, "output drive open drain", NULL), 48 PCONFDUMP(PIN_CONFIG_DRIVE_OPEN_SOURCE, "output drive open source", NULL), 49 PCONFDUMP(PIN_CONFIG_DRIVE_STRENGTH, "output drive strength", "mA"), 50 PCONFDUMP(PIN_CONFIG_INPUT_SCHMITT_ENABLE, "input schmitt enabled", NULL), 51 PCONFDUMP(PIN_CONFIG_INPUT_SCHMITT, "input schmitt trigger", NULL), 52 PCONFDUMP(PIN_CONFIG_INPUT_DEBOUNCE, "input debounce", "usec"), 53 PCONFDUMP(PIN_CONFIG_POWER_SOURCE, "pin power source", "selector"), 54 PCONFDUMP(PIN_CONFIG_SLEW_RATE, "slew rate", NULL), 55 PCONFDUMP(PIN_CONFIG_LOW_POWER_MODE, "pin low power", "mode"), 56 PCONFDUMP(PIN_CONFIG_OUTPUT, "pin output", "level"), 57 }; 58 59 void pinconf_generic_dump_pin(struct pinctrl_dev *pctldev, 60 struct seq_file *s, unsigned pin) 61 { 62 const struct pinconf_ops *ops = pctldev->desc->confops; 63 int i; 64 65 if (!ops->is_generic) 66 return; 67 68 for (i = 0; i < ARRAY_SIZE(conf_items); i++) { 69 unsigned long config; 70 int ret; 71 72 /* We want to check out this parameter */ 73 config = pinconf_to_config_packed(conf_items[i].param, 0); 74 ret = pin_config_get_for_pin(pctldev, pin, &config); 75 /* These are legal errors */ 76 if (ret == -EINVAL || ret == -ENOTSUPP) 77 continue; 78 if (ret) { 79 seq_printf(s, "ERROR READING CONFIG SETTING %d ", i); 80 continue; 81 } 82 /* Space between multiple configs */ 83 seq_puts(s, " "); 84 seq_puts(s, conf_items[i].display); 85 /* Print unit if available */ 86 if (conf_items[i].format && 87 pinconf_to_config_argument(config) != 0) 88 seq_printf(s, " (%u %s)", 89 pinconf_to_config_argument(config), 90 conf_items[i].format); 91 } 92 } 93 94 void pinconf_generic_dump_group(struct pinctrl_dev *pctldev, 95 struct seq_file *s, const char *gname) 96 { 97 const struct pinconf_ops *ops = pctldev->desc->confops; 98 int i; 99 100 if (!ops->is_generic) 101 return; 102 103 for (i = 0; i < ARRAY_SIZE(conf_items); i++) { 104 unsigned long config; 105 int ret; 106 107 /* We want to check out this parameter */ 108 config = pinconf_to_config_packed(conf_items[i].param, 0); 109 ret = pin_config_group_get(dev_name(pctldev->dev), gname, 110 &config); 111 /* These are legal errors */ 112 if (ret == -EINVAL || ret == -ENOTSUPP) 113 continue; 114 if (ret) { 115 seq_printf(s, "ERROR READING CONFIG SETTING %d ", i); 116 continue; 117 } 118 /* Space between multiple configs */ 119 seq_puts(s, " "); 120 seq_puts(s, conf_items[i].display); 121 /* Print unit if available */ 122 if (conf_items[i].format && config != 0) 123 seq_printf(s, " (%u %s)", 124 pinconf_to_config_argument(config), 125 conf_items[i].format); 126 } 127 } 128 129 void pinconf_generic_dump_config(struct pinctrl_dev *pctldev, 130 struct seq_file *s, unsigned long config) 131 { 132 int i; 133 134 for (i = 0; i < ARRAY_SIZE(conf_items); i++) { 135 if (pinconf_to_config_param(config) != conf_items[i].param) 136 continue; 137 seq_printf(s, "%s: 0x%x", conf_items[i].display, 138 pinconf_to_config_argument(config)); 139 } 140 } 141 EXPORT_SYMBOL_GPL(pinconf_generic_dump_config); 142 #endif 143 144 #ifdef CONFIG_OF 145 struct pinconf_generic_dt_params { 146 const char * const property; 147 enum pin_config_param param; 148 u32 default_value; 149 }; 150 151 static struct pinconf_generic_dt_params dt_params[] = { 152 { "bias-disable", PIN_CONFIG_BIAS_DISABLE, 0 }, 153 { "bias-high-impedance", PIN_CONFIG_BIAS_HIGH_IMPEDANCE, 0 }, 154 { "bias-bus-hold", PIN_CONFIG_BIAS_BUS_HOLD, 0 }, 155 { "bias-pull-up", PIN_CONFIG_BIAS_PULL_UP, 1 }, 156 { "bias-pull-down", PIN_CONFIG_BIAS_PULL_DOWN, 1 }, 157 { "bias-pull-pin-default", PIN_CONFIG_BIAS_PULL_PIN_DEFAULT, 1 }, 158 { "drive-push-pull", PIN_CONFIG_DRIVE_PUSH_PULL, 0 }, 159 { "drive-open-drain", PIN_CONFIG_DRIVE_OPEN_DRAIN, 0 }, 160 { "drive-open-source", PIN_CONFIG_DRIVE_OPEN_SOURCE, 0 }, 161 { "drive-strength", PIN_CONFIG_DRIVE_STRENGTH, 0 }, 162 { "input-schmitt-enable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 1 }, 163 { "input-schmitt-disable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 0 }, 164 { "input-debounce", PIN_CONFIG_INPUT_DEBOUNCE, 0 }, 165 { "low-power-enable", PIN_CONFIG_LOW_POWER_MODE, 1 }, 166 { "low-power-disable", PIN_CONFIG_LOW_POWER_MODE, 0 }, 167 { "output-low", PIN_CONFIG_OUTPUT, 0, }, 168 { "output-high", PIN_CONFIG_OUTPUT, 1, }, 169 }; 170 171 /** 172 * pinconf_generic_parse_dt_config() 173 * parse the config properties into generic pinconfig values. 174 * @np: node containing the pinconfig properties 175 * @configs: array with nconfigs entries containing the generic pinconf values 176 * @nconfigs: umber of configurations 177 */ 178 int pinconf_generic_parse_dt_config(struct device_node *np, 179 unsigned long **configs, 180 unsigned int *nconfigs) 181 { 182 unsigned long *cfg; 183 unsigned int ncfg = 0; 184 int ret; 185 int i; 186 u32 val; 187 188 if (!np) 189 return -EINVAL; 190 191 /* allocate a temporary array big enough to hold one of each option */ 192 cfg = kzalloc(sizeof(*cfg) * ARRAY_SIZE(dt_params), GFP_KERNEL); 193 if (!cfg) 194 return -ENOMEM; 195 196 for (i = 0; i < ARRAY_SIZE(dt_params); i++) { 197 struct pinconf_generic_dt_params *par = &dt_params[i]; 198 ret = of_property_read_u32(np, par->property, &val); 199 200 /* property not found */ 201 if (ret == -EINVAL) 202 continue; 203 204 /* use default value, when no value is specified */ 205 if (ret) 206 val = par->default_value; 207 208 pr_debug("found %s with value %u\n", par->property, val); 209 cfg[ncfg] = pinconf_to_config_packed(par->param, val); 210 ncfg++; 211 } 212 213 ret = 0; 214 215 /* no configs found at all */ 216 if (ncfg == 0) { 217 *configs = NULL; 218 *nconfigs = 0; 219 goto out; 220 } 221 222 /* 223 * Now limit the number of configs to the real number of 224 * found properties. 225 */ 226 *configs = kzalloc(ncfg * sizeof(unsigned long), GFP_KERNEL); 227 if (!*configs) { 228 ret = -ENOMEM; 229 goto out; 230 } 231 232 memcpy(*configs, cfg, ncfg * sizeof(unsigned long)); 233 *nconfigs = ncfg; 234 235 out: 236 kfree(cfg); 237 return ret; 238 } 239 #endif 240