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17#include <linux/err.h>
18#include <linux/device.h>
19#include <linux/irq.h>
20#include <linux/gpio/consumer.h>
21#include <linux/termios.h>
22#include <linux/serial_core.h>
23
24#include "serial_mctrl_gpio.h"
25
26struct mctrl_gpios {
27 struct uart_port *port;
28 struct gpio_desc *gpio[UART_GPIO_MAX];
29 int irq[UART_GPIO_MAX];
30 unsigned int mctrl_prev;
31 bool mctrl_on;
32};
33
34static const struct {
35 const char *name;
36 unsigned int mctrl;
37 bool dir_out;
38} mctrl_gpios_desc[UART_GPIO_MAX] = {
39 { "cts", TIOCM_CTS, false, },
40 { "dsr", TIOCM_DSR, false, },
41 { "dcd", TIOCM_CD, false, },
42 { "rng", TIOCM_RNG, false, },
43 { "rts", TIOCM_RTS, true, },
44 { "dtr", TIOCM_DTR, true, },
45 { "out1", TIOCM_OUT1, true, },
46 { "out2", TIOCM_OUT2, true, },
47};
48
49void mctrl_gpio_set(struct mctrl_gpios *gpios, unsigned int mctrl)
50{
51 enum mctrl_gpio_idx i;
52 struct gpio_desc *desc_array[UART_GPIO_MAX];
53 int value_array[UART_GPIO_MAX];
54 unsigned int count = 0;
55
56 for (i = 0; i < UART_GPIO_MAX; i++)
57 if (gpios->gpio[i] && mctrl_gpios_desc[i].dir_out) {
58 desc_array[count] = gpios->gpio[i];
59 value_array[count] = !!(mctrl & mctrl_gpios_desc[i].mctrl);
60 count++;
61 }
62 gpiod_set_array_value(count, desc_array, value_array);
63}
64EXPORT_SYMBOL_GPL(mctrl_gpio_set);
65
66struct gpio_desc *mctrl_gpio_to_gpiod(struct mctrl_gpios *gpios,
67 enum mctrl_gpio_idx gidx)
68{
69 return gpios->gpio[gidx];
70}
71EXPORT_SYMBOL_GPL(mctrl_gpio_to_gpiod);
72
73unsigned int mctrl_gpio_get(struct mctrl_gpios *gpios, unsigned int *mctrl)
74{
75 enum mctrl_gpio_idx i;
76
77 for (i = 0; i < UART_GPIO_MAX; i++) {
78 if (gpios->gpio[i] && !mctrl_gpios_desc[i].dir_out) {
79 if (gpiod_get_value(gpios->gpio[i]))
80 *mctrl |= mctrl_gpios_desc[i].mctrl;
81 else
82 *mctrl &= ~mctrl_gpios_desc[i].mctrl;
83 }
84 }
85
86 return *mctrl;
87}
88EXPORT_SYMBOL_GPL(mctrl_gpio_get);
89
90struct mctrl_gpios *mctrl_gpio_init_noauto(struct device *dev, unsigned int idx)
91{
92 struct mctrl_gpios *gpios;
93 enum mctrl_gpio_idx i;
94
95 gpios = devm_kzalloc(dev, sizeof(*gpios), GFP_KERNEL);
96 if (!gpios)
97 return ERR_PTR(-ENOMEM);
98
99 for (i = 0; i < UART_GPIO_MAX; i++) {
100 enum gpiod_flags flags;
101
102 if (mctrl_gpios_desc[i].dir_out)
103 flags = GPIOD_OUT_LOW;
104 else
105 flags = GPIOD_IN;
106
107 gpios->gpio[i] =
108 devm_gpiod_get_index_optional(dev,
109 mctrl_gpios_desc[i].name,
110 idx, flags);
111
112 if (IS_ERR(gpios->gpio[i]))
113 return ERR_CAST(gpios->gpio[i]);
114 }
115
116 return gpios;
117}
118EXPORT_SYMBOL_GPL(mctrl_gpio_init_noauto);
119
120#define MCTRL_ANY_DELTA (TIOCM_RI | TIOCM_DSR | TIOCM_CD | TIOCM_CTS)
121static irqreturn_t mctrl_gpio_irq_handle(int irq, void *context)
122{
123 struct mctrl_gpios *gpios = context;
124 struct uart_port *port = gpios->port;
125 u32 mctrl = gpios->mctrl_prev;
126 u32 mctrl_diff;
127
128 mctrl_gpio_get(gpios, &mctrl);
129
130 mctrl_diff = mctrl ^ gpios->mctrl_prev;
131 gpios->mctrl_prev = mctrl;
132
133 if (mctrl_diff & MCTRL_ANY_DELTA && port->state != NULL) {
134 if ((mctrl_diff & mctrl) & TIOCM_RI)
135 port->icount.rng++;
136
137 if ((mctrl_diff & mctrl) & TIOCM_DSR)
138 port->icount.dsr++;
139
140 if (mctrl_diff & TIOCM_CD)
141 uart_handle_dcd_change(port, mctrl & TIOCM_CD);
142
143 if (mctrl_diff & TIOCM_CTS)
144 uart_handle_cts_change(port, mctrl & TIOCM_CTS);
145
146 wake_up_interruptible(&port->state->port.delta_msr_wait);
147 }
148
149 return IRQ_HANDLED;
150}
151
152struct mctrl_gpios *mctrl_gpio_init(struct uart_port *port, unsigned int idx)
153{
154 struct mctrl_gpios *gpios;
155 enum mctrl_gpio_idx i;
156
157 gpios = mctrl_gpio_init_noauto(port->dev, idx);
158 if (IS_ERR(gpios))
159 return gpios;
160
161 gpios->port = port;
162
163 for (i = 0; i < UART_GPIO_MAX; ++i) {
164 int ret;
165
166 if (!gpios->gpio[i] || mctrl_gpios_desc[i].dir_out)
167 continue;
168
169 ret = gpiod_to_irq(gpios->gpio[i]);
170 if (ret <= 0) {
171 dev_err(port->dev,
172 "failed to find corresponding irq for %s (idx=%d, err=%d)\n",
173 mctrl_gpios_desc[i].name, idx, ret);
174 return ERR_PTR(ret);
175 }
176 gpios->irq[i] = ret;
177
178
179 irq_set_status_flags(gpios->irq[i], IRQ_NOAUTOEN);
180
181 ret = devm_request_irq(port->dev, gpios->irq[i],
182 mctrl_gpio_irq_handle,
183 IRQ_TYPE_EDGE_BOTH, dev_name(port->dev),
184 gpios);
185 if (ret) {
186
187 dev_err(port->dev,
188 "failed to request irq for %s (idx=%d, err=%d)\n",
189 mctrl_gpios_desc[i].name, idx, ret);
190 return ERR_PTR(ret);
191 }
192 }
193
194 return gpios;
195}
196EXPORT_SYMBOL_GPL(mctrl_gpio_init);
197
198void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios)
199{
200 enum mctrl_gpio_idx i;
201
202 for (i = 0; i < UART_GPIO_MAX; i++) {
203 if (gpios->irq[i])
204 devm_free_irq(gpios->port->dev, gpios->irq[i], gpios);
205
206 if (gpios->gpio[i])
207 devm_gpiod_put(dev, gpios->gpio[i]);
208 }
209 devm_kfree(dev, gpios);
210}
211EXPORT_SYMBOL_GPL(mctrl_gpio_free);
212
213void mctrl_gpio_enable_ms(struct mctrl_gpios *gpios)
214{
215 enum mctrl_gpio_idx i;
216
217
218 if (gpios->mctrl_on)
219 return;
220
221 gpios->mctrl_on = true;
222
223
224 mctrl_gpio_get(gpios, &gpios->mctrl_prev);
225
226 for (i = 0; i < UART_GPIO_MAX; ++i) {
227 if (!gpios->irq[i])
228 continue;
229
230 enable_irq(gpios->irq[i]);
231 }
232}
233EXPORT_SYMBOL_GPL(mctrl_gpio_enable_ms);
234
235void mctrl_gpio_disable_ms(struct mctrl_gpios *gpios)
236{
237 enum mctrl_gpio_idx i;
238
239 if (!gpios->mctrl_on)
240 return;
241
242 gpios->mctrl_on = false;
243
244 for (i = 0; i < UART_GPIO_MAX; ++i) {
245 if (!gpios->irq[i])
246 continue;
247
248 disable_irq(gpios->irq[i]);
249 }
250}
251EXPORT_SYMBOL_GPL(mctrl_gpio_disable_ms);
252
