Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 | /*
* Helpers for controlling modem lines via GPIO
*
* Copyright (C) 2014 Paratronic S.A.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/err.h>
#include <linux/device.h>
#include <linux/irq.h>
#include <linux/gpio/consumer.h>
#include <linux/termios.h>
#include <linux/serial_core.h>
#include <linux/module.h>
#include "serial_mctrl_gpio.h"
struct mctrl_gpios {
struct uart_port *port;
struct gpio_desc *gpio[UART_GPIO_MAX];
int irq[UART_GPIO_MAX];
unsigned int mctrl_prev;
bool mctrl_on;
};
static const struct {
const char *name;
unsigned int mctrl;
bool dir_out;
} mctrl_gpios_desc[UART_GPIO_MAX] = {
{ "cts", TIOCM_CTS, false, },
{ "dsr", TIOCM_DSR, false, },
{ "dcd", TIOCM_CD, false, },
{ "rng", TIOCM_RNG, false, },
{ "rts", TIOCM_RTS, true, },
{ "dtr", TIOCM_DTR, true, },
};
void mctrl_gpio_set(struct mctrl_gpios *gpios, unsigned int mctrl)
{
enum mctrl_gpio_idx i;
struct gpio_desc *desc_array[UART_GPIO_MAX];
int value_array[UART_GPIO_MAX];
unsigned int count = 0;
if (gpios == NULL)
return;
for (i = 0; i < UART_GPIO_MAX; i++)
if (gpios->gpio[i] && mctrl_gpios_desc[i].dir_out) {
desc_array[count] = gpios->gpio[i];
value_array[count] = !!(mctrl & mctrl_gpios_desc[i].mctrl);
count++;
}
gpiod_set_array_value(count, desc_array, value_array);
}
EXPORT_SYMBOL_GPL(mctrl_gpio_set);
struct gpio_desc *mctrl_gpio_to_gpiod(struct mctrl_gpios *gpios,
enum mctrl_gpio_idx gidx)
{
return gpios->gpio[gidx];
}
EXPORT_SYMBOL_GPL(mctrl_gpio_to_gpiod);
unsigned int mctrl_gpio_get(struct mctrl_gpios *gpios, unsigned int *mctrl)
{
enum mctrl_gpio_idx i;
if (gpios == NULL)
return *mctrl;
for (i = 0; i < UART_GPIO_MAX; i++) {
if (gpios->gpio[i] && !mctrl_gpios_desc[i].dir_out) {
if (gpiod_get_value(gpios->gpio[i]))
*mctrl |= mctrl_gpios_desc[i].mctrl;
else
*mctrl &= ~mctrl_gpios_desc[i].mctrl;
}
}
return *mctrl;
}
EXPORT_SYMBOL_GPL(mctrl_gpio_get);
unsigned int
mctrl_gpio_get_outputs(struct mctrl_gpios *gpios, unsigned int *mctrl)
{
enum mctrl_gpio_idx i;
if (gpios == NULL)
return *mctrl;
for (i = 0; i < UART_GPIO_MAX; i++) {
if (gpios->gpio[i] && mctrl_gpios_desc[i].dir_out) {
if (gpiod_get_value(gpios->gpio[i]))
*mctrl |= mctrl_gpios_desc[i].mctrl;
else
*mctrl &= ~mctrl_gpios_desc[i].mctrl;
}
}
return *mctrl;
}
EXPORT_SYMBOL_GPL(mctrl_gpio_get_outputs);
struct mctrl_gpios *mctrl_gpio_init_noauto(struct device *dev, unsigned int idx)
{
struct mctrl_gpios *gpios;
enum mctrl_gpio_idx i;
gpios = devm_kzalloc(dev, sizeof(*gpios), GFP_KERNEL);
if (!gpios)
return ERR_PTR(-ENOMEM);
for (i = 0; i < UART_GPIO_MAX; i++) {
enum gpiod_flags flags;
if (mctrl_gpios_desc[i].dir_out)
flags = GPIOD_OUT_LOW;
else
flags = GPIOD_IN;
gpios->gpio[i] =
devm_gpiod_get_index_optional(dev,
mctrl_gpios_desc[i].name,
idx, flags);
if (IS_ERR(gpios->gpio[i]))
return ERR_CAST(gpios->gpio[i]);
}
return gpios;
}
EXPORT_SYMBOL_GPL(mctrl_gpio_init_noauto);
#define MCTRL_ANY_DELTA (TIOCM_RI | TIOCM_DSR | TIOCM_CD | TIOCM_CTS)
static irqreturn_t mctrl_gpio_irq_handle(int irq, void *context)
{
struct mctrl_gpios *gpios = context;
struct uart_port *port = gpios->port;
u32 mctrl = gpios->mctrl_prev;
u32 mctrl_diff;
unsigned long flags;
mctrl_gpio_get(gpios, &mctrl);
spin_lock_irqsave(&port->lock, flags);
mctrl_diff = mctrl ^ gpios->mctrl_prev;
gpios->mctrl_prev = mctrl;
if (mctrl_diff & MCTRL_ANY_DELTA && port->state != NULL) {
if ((mctrl_diff & mctrl) & TIOCM_RI)
port->icount.rng++;
if ((mctrl_diff & mctrl) & TIOCM_DSR)
port->icount.dsr++;
if (mctrl_diff & TIOCM_CD)
uart_handle_dcd_change(port, mctrl & TIOCM_CD);
if (mctrl_diff & TIOCM_CTS)
uart_handle_cts_change(port, mctrl & TIOCM_CTS);
wake_up_interruptible(&port->state->port.delta_msr_wait);
}
spin_unlock_irqrestore(&port->lock, flags);
return IRQ_HANDLED;
}
struct mctrl_gpios *mctrl_gpio_init(struct uart_port *port, unsigned int idx)
{
struct mctrl_gpios *gpios;
enum mctrl_gpio_idx i;
gpios = mctrl_gpio_init_noauto(port->dev, idx);
if (IS_ERR(gpios))
return gpios;
gpios->port = port;
for (i = 0; i < UART_GPIO_MAX; ++i) {
int ret;
if (!gpios->gpio[i] || mctrl_gpios_desc[i].dir_out)
continue;
ret = gpiod_to_irq(gpios->gpio[i]);
if (ret <= 0) {
dev_err(port->dev,
"failed to find corresponding irq for %s (idx=%d, err=%d)\n",
mctrl_gpios_desc[i].name, idx, ret);
return ERR_PTR(ret);
}
gpios->irq[i] = ret;
/* irqs should only be enabled in .enable_ms */
irq_set_status_flags(gpios->irq[i], IRQ_NOAUTOEN);
ret = devm_request_irq(port->dev, gpios->irq[i],
mctrl_gpio_irq_handle,
IRQ_TYPE_EDGE_BOTH, dev_name(port->dev),
gpios);
if (ret) {
/* alternatively implement polling */
dev_err(port->dev,
"failed to request irq for %s (idx=%d, err=%d)\n",
mctrl_gpios_desc[i].name, idx, ret);
return ERR_PTR(ret);
}
}
return gpios;
}
EXPORT_SYMBOL_GPL(mctrl_gpio_init);
void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios)
{
enum mctrl_gpio_idx i;
if (gpios == NULL)
return;
for (i = 0; i < UART_GPIO_MAX; i++) {
if (gpios->irq[i])
devm_free_irq(gpios->port->dev, gpios->irq[i], gpios);
if (gpios->gpio[i])
devm_gpiod_put(dev, gpios->gpio[i]);
}
devm_kfree(dev, gpios);
}
EXPORT_SYMBOL_GPL(mctrl_gpio_free);
void mctrl_gpio_enable_ms(struct mctrl_gpios *gpios)
{
enum mctrl_gpio_idx i;
if (gpios == NULL)
return;
/* .enable_ms may be called multiple times */
if (gpios->mctrl_on)
return;
gpios->mctrl_on = true;
/* get initial status of modem lines GPIOs */
mctrl_gpio_get(gpios, &gpios->mctrl_prev);
for (i = 0; i < UART_GPIO_MAX; ++i) {
if (!gpios->irq[i])
continue;
enable_irq(gpios->irq[i]);
}
}
EXPORT_SYMBOL_GPL(mctrl_gpio_enable_ms);
void mctrl_gpio_disable_ms(struct mctrl_gpios *gpios)
{
enum mctrl_gpio_idx i;
if (gpios == NULL)
return;
if (!gpios->mctrl_on)
return;
gpios->mctrl_on = false;
for (i = 0; i < UART_GPIO_MAX; ++i) {
if (!gpios->irq[i])
continue;
disable_irq(gpios->irq[i]);
}
}
EXPORT_SYMBOL_GPL(mctrl_gpio_disable_ms);
MODULE_LICENSE("GPL");
|