drivers/gpio/tegra_gpio.c

   1 /*
   2  * NVIDIA Tegra2 GPIO handling.
   3  *  (C) Copyright 2010-2012
   4  *  NVIDIA Corporation <www.nvidia.com>
   5  *
   6  * See file CREDITS for list of people who contributed to this
   7  * project.
   8  *
   9  * This program is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU General Public License as
  11  * published by the Free Software Foundation; either version 2 of
  12  * the License, or (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  22  * MA 02111-1307 USA
  23  */
  24
  25 /*
  26  * Based on (mostly copied from) kw_gpio.c based Linux 2.6 kernel driver.
  27  * Tom Warren (twarren@nvidia.com)
  28  */
  29
  30 #include <common.h>
  31 #include <asm/io.h>
  32 #include <asm/bitops.h>
  33 #include <asm/arch/tegra2.h>
  34 #include <asm/gpio.h>
  35
  36 enum {
  37         TEGRA2_CMD_INFO,
  38         TEGRA2_CMD_PORT,
  39         TEGRA2_CMD_OUTPUT,
  40         TEGRA2_CMD_INPUT,
  41 };
  42
  43 static struct gpio_names {
  44         char name[GPIO_NAME_SIZE];
  45 } gpio_names[MAX_NUM_GPIOS];
  46
  47 static char *get_name(int i)
  48 {
  49         return *gpio_names[i].name ? gpio_names[i].name : "UNKNOWN";
  50 }
  51
  52 /* Return config of pin 'gpio' as GPIO (1) or SFPIO (0) */
  53 static int get_config(unsigned gpio)
  54 {
  55         struct gpio_ctlr *ctlr = (struct gpio_ctlr *)NV_PA_GPIO_BASE;
  56         struct gpio_ctlr_bank *bank = &ctlr->gpio_bank[GPIO_BANK(gpio)];
  57         u32 u;
  58         int type;
  59
  60         u = readl(&bank->gpio_config[GPIO_PORT(gpio)]);
  61         type =  (u >> GPIO_BIT(gpio)) & 1;
  62
  63         debug("get_config: port = %d, bit = %d is %s\n",
  64                 GPIO_FULLPORT(gpio), GPIO_BIT(gpio), type ? "GPIO" : "SFPIO");
  65
  66         return type;
  67 }
  68
  69 /* Config pin 'gpio' as GPIO or SFPIO, based on 'type' */
  70 static void set_config(unsigned gpio, int type)
  71 {
  72         struct gpio_ctlr *ctlr = (struct gpio_ctlr *)NV_PA_GPIO_BASE;
  73         struct gpio_ctlr_bank *bank = &ctlr->gpio_bank[GPIO_BANK(gpio)];
  74         u32 u;
  75
  76         debug("set_config: port = %d, bit = %d, %s\n",
  77                 GPIO_FULLPORT(gpio), GPIO_BIT(gpio), type ? "GPIO" : "SFPIO");
  78
  79         u = readl(&bank->gpio_config[GPIO_PORT(gpio)]);
  80         if (type)                               /* GPIO */
  81                 u |= 1 << GPIO_BIT(gpio);
  82         else
  83                 u &= ~(1 << GPIO_BIT(gpio));
  84         writel(u, &bank->gpio_config[GPIO_PORT(gpio)]);
  85 }
  86
  87 /* Return GPIO pin 'gpio' direction - 0 = input or 1 = output */
  88 static int get_direction(unsigned gpio)
  89 {
  90         struct gpio_ctlr *ctlr = (struct gpio_ctlr *)NV_PA_GPIO_BASE;
  91         struct gpio_ctlr_bank *bank = &ctlr->gpio_bank[GPIO_BANK(gpio)];
  92         u32 u;
  93         int dir;
  94
  95         u = readl(&bank->gpio_dir_out[GPIO_PORT(gpio)]);
  96         dir =  (u >> GPIO_BIT(gpio)) & 1;
  97
  98         debug("get_direction: port = %d, bit = %d, %s\n",
  99                 GPIO_FULLPORT(gpio), GPIO_BIT(gpio), dir ? "OUT" : "IN");
 100
 101         return dir;
 102 }
 103
 104 /* Config GPIO pin 'gpio' as input or output (OE) as per 'output' */
 105 static void set_direction(unsigned gpio, int output)
 106 {
 107         struct gpio_ctlr *ctlr = (struct gpio_ctlr *)NV_PA_GPIO_BASE;
 108         struct gpio_ctlr_bank *bank = &ctlr->gpio_bank[GPIO_BANK(gpio)];
 109         u32 u;
 110
 111         debug("set_direction: port = %d, bit = %d, %s\n",
 112                 GPIO_FULLPORT(gpio), GPIO_BIT(gpio), output ? "OUT" : "IN");
 113
 114         u = readl(&bank->gpio_dir_out[GPIO_PORT(gpio)]);
 115         if (output)
 116                 u |= 1 << GPIO_BIT(gpio);
 117         else
 118                 u &= ~(1 << GPIO_BIT(gpio));
 119         writel(u, &bank->gpio_dir_out[GPIO_PORT(gpio)]);
 120 }
 121
 122 /* set GPIO pin 'gpio' output bit as 0 or 1 as per 'high' */
 123 static void set_level(unsigned gpio, int high)
 124 {
 125         struct gpio_ctlr *ctlr = (struct gpio_ctlr *)NV_PA_GPIO_BASE;
 126         struct gpio_ctlr_bank *bank = &ctlr->gpio_bank[GPIO_BANK(gpio)];
 127         u32 u;
 128
 129         debug("set_level: port = %d, bit %d == %d\n",
 130                 GPIO_FULLPORT(gpio), GPIO_BIT(gpio), high);
 131
 132         u = readl(&bank->gpio_out[GPIO_PORT(gpio)]);
 133         if (high)
 134                 u |= 1 << GPIO_BIT(gpio);
 135         else
 136                 u &= ~(1 << GPIO_BIT(gpio));
 137         writel(u, &bank->gpio_out[GPIO_PORT(gpio)]);
 138 }
 139
 140 /*
 141  * Generic_GPIO primitives.
 142  */
 143
 144 int gpio_request(unsigned gpio, const char *label)
 145 {
 146         if (gpio >= MAX_NUM_GPIOS)
 147                 return -1;
 148
 149         if (label != NULL) {
 150                 strncpy(gpio_names[gpio].name, label, GPIO_NAME_SIZE);
 151                 gpio_names[gpio].name[GPIO_NAME_SIZE - 1] = '\0';
 152         }
 153
 154         /* Configure as a GPIO */
 155         set_config(gpio, 1);
 156
 157         return 0;
 158 }
 159
 160 int gpio_free(unsigned gpio)
 161 {
 162         if (gpio >= MAX_NUM_GPIOS)
 163                 return -1;
 164
 165         gpio_names[gpio].name[0] = '\0';
 166         /* Do not configure as input or change pin mux here */
 167         return 0;
 168 }
 169
 170 /* read GPIO OUT value of pin 'gpio' */
 171 static int gpio_get_output_value(unsigned gpio)
 172 {
 173         struct gpio_ctlr *ctlr = (struct gpio_ctlr *)NV_PA_GPIO_BASE;
 174         struct gpio_ctlr_bank *bank = &ctlr->gpio_bank[GPIO_BANK(gpio)];
 175         int val;
 176
 177         debug("gpio_get_output_value: pin = %d (port %d:bit %d)\n",
 178                 gpio, GPIO_FULLPORT(gpio), GPIO_BIT(gpio));
 179
 180         val = readl(&bank->gpio_out[GPIO_PORT(gpio)]);
 181
 182         return (val >> GPIO_BIT(gpio)) & 1;
 183 }
 184
 185 /* set GPIO pin 'gpio' as an input */
 186 int gpio_direction_input(unsigned gpio)
 187 {
 188         debug("gpio_direction_input: pin = %d (port %d:bit %d)\n",
 189                 gpio, GPIO_FULLPORT(gpio), GPIO_BIT(gpio));
 190
 191         /* Configure GPIO direction as input. */
 192         set_direction(gpio, 0);
 193
 194         return 0;
 195 }
 196
 197 /* set GPIO pin 'gpio' as an output, with polarity 'value' */
 198 int gpio_direction_output(unsigned gpio, int value)
 199 {
 200         debug("gpio_direction_output: pin = %d (port %d:bit %d) = %s\n",
 201                 gpio, GPIO_FULLPORT(gpio), GPIO_BIT(gpio),
 202                 value ? "HIGH" : "LOW");
 203
 204         /* Configure GPIO output value. */
 205         set_level(gpio, value);
 206
 207         /* Configure GPIO direction as output. */
 208         set_direction(gpio, 1);
 209
 210         return 0;
 211 }
 212
 213 /* read GPIO IN value of pin 'gpio' */
 214 int gpio_get_value(unsigned gpio)
 215 {
 216         struct gpio_ctlr *ctlr = (struct gpio_ctlr *)NV_PA_GPIO_BASE;
 217         struct gpio_ctlr_bank *bank = &ctlr->gpio_bank[GPIO_BANK(gpio)];
 218         int val;
 219
 220         debug("gpio_get_value: pin = %d (port %d:bit %d)\n",
 221                 gpio, GPIO_FULLPORT(gpio), GPIO_BIT(gpio));
 222
 223         val = readl(&bank->gpio_in[GPIO_PORT(gpio)]);
 224
 225         return (val >> GPIO_BIT(gpio)) & 1;
 226 }
 227
 228 /* write GPIO OUT value to pin 'gpio' */
 229 int gpio_set_value(unsigned gpio, int value)
 230 {
 231         debug("gpio_set_value: pin = %d (port %d:bit %d), value = %d\n",
 232                 gpio, GPIO_FULLPORT(gpio), GPIO_BIT(gpio), value);
 233
 234         /* Configure GPIO output value. */
 235         set_level(gpio, value);
 236
 237         return 0;
 238 }
 239
 240 /*
 241  * Display Tegra GPIO information
 242  */
 243 void gpio_info(void)
 244 {
 245         unsigned c;
 246         int type;
 247
 248         for (c = 0; c < MAX_NUM_GPIOS; c++) {
 249                 type = get_config(c);           /* GPIO, not SFPIO */
 250                 if (type) {
 251                         printf("GPIO_%d:\t%s is an %s, ", c,
 252                                 get_name(c),
 253                                 get_direction(c) ? "OUTPUT" : "INPUT");
 254                         if (get_direction(c))
 255                                 printf("value = %d", gpio_get_output_value(c));
 256                         else
 257                                 printf("value = %d", gpio_get_value(c));
 258                         printf("\n");
 259                 } else
 260                         continue;
 261         }
 262 }