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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2018, NVIDIA CORPORATION. All rights reserved.
4 */
5
6#include <linux/console.h>
7#include <linux/mailbox_client.h>
8#include <linux/module.h>
9#include <linux/of.h>
10#include <linux/platform_device.h>
11#include <linux/serial.h>
12#include <linux/serial_core.h>
13#include <linux/slab.h>
14#include <linux/tty.h>
15#include <linux/tty_flip.h>
16
17#define TCU_MBOX_BYTE(i, x) ((x) << (i * 8))
18#define TCU_MBOX_BYTE_V(x, i) (((x) >> (i * 8)) & 0xff)
19#define TCU_MBOX_NUM_BYTES(x) ((x) << 24)
20#define TCU_MBOX_NUM_BYTES_V(x) (((x) >> 24) & 0x3)
21
22struct tegra_tcu {
23 struct uart_driver driver;
24#if IS_ENABLED(CONFIG_SERIAL_TEGRA_TCU_CONSOLE)
25 struct console console;
26#endif
27 struct uart_port port;
28
29 struct mbox_client tx_client, rx_client;
30 struct mbox_chan *tx, *rx;
31};
32
33static unsigned int tegra_tcu_uart_tx_empty(struct uart_port *port)
34{
35 return TIOCSER_TEMT;
36}
37
38static void tegra_tcu_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
39{
40}
41
42static unsigned int tegra_tcu_uart_get_mctrl(struct uart_port *port)
43{
44 return 0;
45}
46
47static void tegra_tcu_uart_stop_tx(struct uart_port *port)
48{
49}
50
51static void tegra_tcu_write_one(struct tegra_tcu *tcu, u32 value,
52 unsigned int count)
53{
54 void *msg;
55
56 value |= TCU_MBOX_NUM_BYTES(count);
57 msg = (void *)(unsigned long)value;
58 mbox_send_message(tcu->tx, msg);
59 mbox_flush(tcu->tx, 1000);
60}
61
62static void tegra_tcu_write(struct tegra_tcu *tcu, const char *s,
63 unsigned int count)
64{
65 unsigned int written = 0, i = 0;
66 bool insert_nl = false;
67 u32 value = 0;
68
69 while (i < count) {
70 if (insert_nl) {
71 value |= TCU_MBOX_BYTE(written++, '\n');
72 insert_nl = false;
73 i++;
74 } else if (s[i] == '\n') {
75 value |= TCU_MBOX_BYTE(written++, '\r');
76 insert_nl = true;
77 } else {
78 value |= TCU_MBOX_BYTE(written++, s[i++]);
79 }
80
81 if (written == 3) {
82 tegra_tcu_write_one(tcu, value, 3);
83 value = written = 0;
84 }
85 }
86
87 if (written)
88 tegra_tcu_write_one(tcu, value, written);
89}
90
91static void tegra_tcu_uart_start_tx(struct uart_port *port)
92{
93 struct tegra_tcu *tcu = port->private_data;
94 struct circ_buf *xmit = &port->state->xmit;
95 unsigned long count;
96
97 for (;;) {
98 count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
99 if (!count)
100 break;
101
102 tegra_tcu_write(tcu, &xmit->buf[xmit->tail], count);
103 uart_xmit_advance(port, count);
104 }
105
106 uart_write_wakeup(port);
107}
108
109static void tegra_tcu_uart_stop_rx(struct uart_port *port)
110{
111}
112
113static void tegra_tcu_uart_break_ctl(struct uart_port *port, int ctl)
114{
115}
116
117static int tegra_tcu_uart_startup(struct uart_port *port)
118{
119 return 0;
120}
121
122static void tegra_tcu_uart_shutdown(struct uart_port *port)
123{
124}
125
126static void tegra_tcu_uart_set_termios(struct uart_port *port,
127 struct ktermios *new,
128 const struct ktermios *old)
129{
130}
131
132static const struct uart_ops tegra_tcu_uart_ops = {
133 .tx_empty = tegra_tcu_uart_tx_empty,
134 .set_mctrl = tegra_tcu_uart_set_mctrl,
135 .get_mctrl = tegra_tcu_uart_get_mctrl,
136 .stop_tx = tegra_tcu_uart_stop_tx,
137 .start_tx = tegra_tcu_uart_start_tx,
138 .stop_rx = tegra_tcu_uart_stop_rx,
139 .break_ctl = tegra_tcu_uart_break_ctl,
140 .startup = tegra_tcu_uart_startup,
141 .shutdown = tegra_tcu_uart_shutdown,
142 .set_termios = tegra_tcu_uart_set_termios,
143};
144
145#if IS_ENABLED(CONFIG_SERIAL_TEGRA_TCU_CONSOLE)
146static void tegra_tcu_console_write(struct console *cons, const char *s,
147 unsigned int count)
148{
149 struct tegra_tcu *tcu = container_of(cons, struct tegra_tcu, console);
150
151 tegra_tcu_write(tcu, s, count);
152}
153
154static int tegra_tcu_console_setup(struct console *cons, char *options)
155{
156 return 0;
157}
158#endif
159
160static void tegra_tcu_receive(struct mbox_client *cl, void *msg)
161{
162 struct tegra_tcu *tcu = container_of(cl, struct tegra_tcu, rx_client);
163 struct tty_port *port = &tcu->port.state->port;
164 u32 value = (u32)(unsigned long)msg;
165 unsigned int num_bytes, i;
166
167 num_bytes = TCU_MBOX_NUM_BYTES_V(value);
168
169 for (i = 0; i < num_bytes; i++)
170 tty_insert_flip_char(port, TCU_MBOX_BYTE_V(value, i),
171 TTY_NORMAL);
172
173 tty_flip_buffer_push(port);
174}
175
176static int tegra_tcu_probe(struct platform_device *pdev)
177{
178 struct uart_port *port;
179 struct tegra_tcu *tcu;
180 int err;
181
182 tcu = devm_kzalloc(&pdev->dev, sizeof(*tcu), GFP_KERNEL);
183 if (!tcu)
184 return -ENOMEM;
185
186 tcu->tx_client.dev = &pdev->dev;
187 tcu->rx_client.dev = &pdev->dev;
188 tcu->rx_client.rx_callback = tegra_tcu_receive;
189
190 tcu->tx = mbox_request_channel_byname(&tcu->tx_client, "tx");
191 if (IS_ERR(tcu->tx)) {
192 err = PTR_ERR(tcu->tx);
193 dev_err(&pdev->dev, "failed to get tx mailbox: %d\n", err);
194 return err;
195 }
196
197#if IS_ENABLED(CONFIG_SERIAL_TEGRA_TCU_CONSOLE)
198 /* setup the console */
199 strcpy(tcu->console.name, "ttyTCU");
200 tcu->console.device = uart_console_device;
201 tcu->console.flags = CON_PRINTBUFFER | CON_ANYTIME;
202 tcu->console.index = -1;
203 tcu->console.write = tegra_tcu_console_write;
204 tcu->console.setup = tegra_tcu_console_setup;
205 tcu->console.data = &tcu->driver;
206#endif
207
208 /* setup the driver */
209 tcu->driver.owner = THIS_MODULE;
210 tcu->driver.driver_name = "tegra-tcu";
211 tcu->driver.dev_name = "ttyTCU";
212#if IS_ENABLED(CONFIG_SERIAL_TEGRA_TCU_CONSOLE)
213 tcu->driver.cons = &tcu->console;
214#endif
215 tcu->driver.nr = 1;
216
217 err = uart_register_driver(&tcu->driver);
218 if (err) {
219 dev_err(&pdev->dev, "failed to register UART driver: %d\n",
220 err);
221 goto free_tx;
222 }
223
224 /* setup the port */
225 port = &tcu->port;
226 spin_lock_init(&port->lock);
227 port->dev = &pdev->dev;
228 port->type = PORT_TEGRA_TCU;
229 port->ops = &tegra_tcu_uart_ops;
230 port->fifosize = 1;
231 port->iotype = UPIO_MEM;
232 port->flags = UPF_BOOT_AUTOCONF;
233 port->private_data = tcu;
234
235 err = uart_add_one_port(&tcu->driver, port);
236 if (err) {
237 dev_err(&pdev->dev, "failed to add UART port: %d\n", err);
238 goto unregister_uart;
239 }
240
241 /*
242 * Request RX channel after creating port to ensure tcu->port
243 * is ready for any immediate incoming bytes.
244 */
245 tcu->rx = mbox_request_channel_byname(&tcu->rx_client, "rx");
246 if (IS_ERR(tcu->rx)) {
247 err = PTR_ERR(tcu->rx);
248 dev_err(&pdev->dev, "failed to get rx mailbox: %d\n", err);
249 goto remove_uart_port;
250 }
251
252 platform_set_drvdata(pdev, tcu);
253#if IS_ENABLED(CONFIG_SERIAL_TEGRA_TCU_CONSOLE)
254 register_console(&tcu->console);
255#endif
256
257 return 0;
258
259remove_uart_port:
260 uart_remove_one_port(&tcu->driver, &tcu->port);
261unregister_uart:
262 uart_unregister_driver(&tcu->driver);
263free_tx:
264 mbox_free_channel(tcu->tx);
265
266 return err;
267}
268
269static void tegra_tcu_remove(struct platform_device *pdev)
270{
271 struct tegra_tcu *tcu = platform_get_drvdata(pdev);
272
273#if IS_ENABLED(CONFIG_SERIAL_TEGRA_TCU_CONSOLE)
274 unregister_console(&tcu->console);
275#endif
276 mbox_free_channel(tcu->rx);
277 uart_remove_one_port(&tcu->driver, &tcu->port);
278 uart_unregister_driver(&tcu->driver);
279 mbox_free_channel(tcu->tx);
280}
281
282static const struct of_device_id tegra_tcu_match[] = {
283 { .compatible = "nvidia,tegra194-tcu" },
284 { }
285};
286MODULE_DEVICE_TABLE(of, tegra_tcu_match);
287
288static struct platform_driver tegra_tcu_driver = {
289 .driver = {
290 .name = "tegra-tcu",
291 .of_match_table = tegra_tcu_match,
292 },
293 .probe = tegra_tcu_probe,
294 .remove_new = tegra_tcu_remove,
295};
296module_platform_driver(tegra_tcu_driver);
297
298MODULE_AUTHOR("Mikko Perttunen <mperttunen@nvidia.com>");
299MODULE_LICENSE("GPL v2");
300MODULE_DESCRIPTION("NVIDIA Tegra Combined UART driver");
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2018, NVIDIA CORPORATION. All rights reserved.
4 */
5
6#include <linux/console.h>
7#include <linux/mailbox_client.h>
8#include <linux/module.h>
9#include <linux/of.h>
10#include <linux/platform_device.h>
11#include <linux/serial.h>
12#include <linux/serial_core.h>
13#include <linux/slab.h>
14#include <linux/tty.h>
15#include <linux/tty_flip.h>
16
17#define TCU_MBOX_BYTE(i, x) ((x) << (i * 8))
18#define TCU_MBOX_BYTE_V(x, i) (((x) >> (i * 8)) & 0xff)
19#define TCU_MBOX_NUM_BYTES(x) ((x) << 24)
20#define TCU_MBOX_NUM_BYTES_V(x) (((x) >> 24) & 0x3)
21
22struct tegra_tcu {
23 struct uart_driver driver;
24#if IS_ENABLED(CONFIG_SERIAL_TEGRA_TCU_CONSOLE)
25 struct console console;
26#endif
27 struct uart_port port;
28
29 struct mbox_client tx_client, rx_client;
30 struct mbox_chan *tx, *rx;
31};
32
33static unsigned int tegra_tcu_uart_tx_empty(struct uart_port *port)
34{
35 return TIOCSER_TEMT;
36}
37
38static void tegra_tcu_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
39{
40}
41
42static unsigned int tegra_tcu_uart_get_mctrl(struct uart_port *port)
43{
44 return 0;
45}
46
47static void tegra_tcu_uart_stop_tx(struct uart_port *port)
48{
49}
50
51static void tegra_tcu_write_one(struct tegra_tcu *tcu, u32 value,
52 unsigned int count)
53{
54 void *msg;
55
56 value |= TCU_MBOX_NUM_BYTES(count);
57 msg = (void *)(unsigned long)value;
58 mbox_send_message(tcu->tx, msg);
59 mbox_flush(tcu->tx, 1000);
60}
61
62static void tegra_tcu_write(struct tegra_tcu *tcu, const char *s,
63 unsigned int count)
64{
65 unsigned int written = 0, i = 0;
66 bool insert_nl = false;
67 u32 value = 0;
68
69 while (i < count) {
70 if (insert_nl) {
71 value |= TCU_MBOX_BYTE(written++, '\n');
72 insert_nl = false;
73 i++;
74 } else if (s[i] == '\n') {
75 value |= TCU_MBOX_BYTE(written++, '\r');
76 insert_nl = true;
77 } else {
78 value |= TCU_MBOX_BYTE(written++, s[i++]);
79 }
80
81 if (written == 3) {
82 tegra_tcu_write_one(tcu, value, 3);
83 value = written = 0;
84 }
85 }
86
87 if (written)
88 tegra_tcu_write_one(tcu, value, written);
89}
90
91static void tegra_tcu_uart_start_tx(struct uart_port *port)
92{
93 struct tegra_tcu *tcu = port->private_data;
94 struct tty_port *tport = &port->state->port;
95 unsigned char *tail;
96 unsigned int count;
97
98 for (;;) {
99 count = kfifo_out_linear_ptr(&tport->xmit_fifo, &tail,
100 UART_XMIT_SIZE);
101 if (!count)
102 break;
103
104 tegra_tcu_write(tcu, tail, count);
105 uart_xmit_advance(port, count);
106 }
107
108 uart_write_wakeup(port);
109}
110
111static void tegra_tcu_uart_stop_rx(struct uart_port *port)
112{
113}
114
115static void tegra_tcu_uart_break_ctl(struct uart_port *port, int ctl)
116{
117}
118
119static int tegra_tcu_uart_startup(struct uart_port *port)
120{
121 return 0;
122}
123
124static void tegra_tcu_uart_shutdown(struct uart_port *port)
125{
126}
127
128static void tegra_tcu_uart_set_termios(struct uart_port *port,
129 struct ktermios *new,
130 const struct ktermios *old)
131{
132}
133
134static const struct uart_ops tegra_tcu_uart_ops = {
135 .tx_empty = tegra_tcu_uart_tx_empty,
136 .set_mctrl = tegra_tcu_uart_set_mctrl,
137 .get_mctrl = tegra_tcu_uart_get_mctrl,
138 .stop_tx = tegra_tcu_uart_stop_tx,
139 .start_tx = tegra_tcu_uart_start_tx,
140 .stop_rx = tegra_tcu_uart_stop_rx,
141 .break_ctl = tegra_tcu_uart_break_ctl,
142 .startup = tegra_tcu_uart_startup,
143 .shutdown = tegra_tcu_uart_shutdown,
144 .set_termios = tegra_tcu_uart_set_termios,
145};
146
147#if IS_ENABLED(CONFIG_SERIAL_TEGRA_TCU_CONSOLE)
148static void tegra_tcu_console_write(struct console *cons, const char *s,
149 unsigned int count)
150{
151 struct tegra_tcu *tcu = container_of(cons, struct tegra_tcu, console);
152
153 tegra_tcu_write(tcu, s, count);
154}
155
156static int tegra_tcu_console_setup(struct console *cons, char *options)
157{
158 return 0;
159}
160#endif
161
162static void tegra_tcu_receive(struct mbox_client *cl, void *msg)
163{
164 struct tegra_tcu *tcu = container_of(cl, struct tegra_tcu, rx_client);
165 struct tty_port *port = &tcu->port.state->port;
166 u32 value = (u32)(unsigned long)msg;
167 unsigned int num_bytes, i;
168
169 num_bytes = TCU_MBOX_NUM_BYTES_V(value);
170
171 for (i = 0; i < num_bytes; i++)
172 tty_insert_flip_char(port, TCU_MBOX_BYTE_V(value, i),
173 TTY_NORMAL);
174
175 tty_flip_buffer_push(port);
176}
177
178static int tegra_tcu_probe(struct platform_device *pdev)
179{
180 struct uart_port *port;
181 struct tegra_tcu *tcu;
182 int err;
183
184 tcu = devm_kzalloc(&pdev->dev, sizeof(*tcu), GFP_KERNEL);
185 if (!tcu)
186 return -ENOMEM;
187
188 tcu->tx_client.dev = &pdev->dev;
189 tcu->rx_client.dev = &pdev->dev;
190 tcu->rx_client.rx_callback = tegra_tcu_receive;
191
192 tcu->tx = mbox_request_channel_byname(&tcu->tx_client, "tx");
193 if (IS_ERR(tcu->tx)) {
194 err = PTR_ERR(tcu->tx);
195 dev_err(&pdev->dev, "failed to get tx mailbox: %d\n", err);
196 return err;
197 }
198
199#if IS_ENABLED(CONFIG_SERIAL_TEGRA_TCU_CONSOLE)
200 /* setup the console */
201 strcpy(tcu->console.name, "ttyTCU");
202 tcu->console.device = uart_console_device;
203 tcu->console.flags = CON_PRINTBUFFER | CON_ANYTIME;
204 tcu->console.index = -1;
205 tcu->console.write = tegra_tcu_console_write;
206 tcu->console.setup = tegra_tcu_console_setup;
207 tcu->console.data = &tcu->driver;
208#endif
209
210 /* setup the driver */
211 tcu->driver.owner = THIS_MODULE;
212 tcu->driver.driver_name = "tegra-tcu";
213 tcu->driver.dev_name = "ttyTCU";
214#if IS_ENABLED(CONFIG_SERIAL_TEGRA_TCU_CONSOLE)
215 tcu->driver.cons = &tcu->console;
216#endif
217 tcu->driver.nr = 1;
218
219 err = uart_register_driver(&tcu->driver);
220 if (err) {
221 dev_err(&pdev->dev, "failed to register UART driver: %d\n",
222 err);
223 goto free_tx;
224 }
225
226 /* setup the port */
227 port = &tcu->port;
228 spin_lock_init(&port->lock);
229 port->dev = &pdev->dev;
230 port->type = PORT_TEGRA_TCU;
231 port->ops = &tegra_tcu_uart_ops;
232 port->fifosize = 1;
233 port->iotype = UPIO_MEM;
234 port->flags = UPF_BOOT_AUTOCONF;
235 port->private_data = tcu;
236
237 err = uart_add_one_port(&tcu->driver, port);
238 if (err) {
239 dev_err(&pdev->dev, "failed to add UART port: %d\n", err);
240 goto unregister_uart;
241 }
242
243 /*
244 * Request RX channel after creating port to ensure tcu->port
245 * is ready for any immediate incoming bytes.
246 */
247 tcu->rx = mbox_request_channel_byname(&tcu->rx_client, "rx");
248 if (IS_ERR(tcu->rx)) {
249 err = PTR_ERR(tcu->rx);
250 dev_err(&pdev->dev, "failed to get rx mailbox: %d\n", err);
251 goto remove_uart_port;
252 }
253
254 platform_set_drvdata(pdev, tcu);
255#if IS_ENABLED(CONFIG_SERIAL_TEGRA_TCU_CONSOLE)
256 register_console(&tcu->console);
257#endif
258
259 return 0;
260
261remove_uart_port:
262 uart_remove_one_port(&tcu->driver, &tcu->port);
263unregister_uart:
264 uart_unregister_driver(&tcu->driver);
265free_tx:
266 mbox_free_channel(tcu->tx);
267
268 return err;
269}
270
271static void tegra_tcu_remove(struct platform_device *pdev)
272{
273 struct tegra_tcu *tcu = platform_get_drvdata(pdev);
274
275#if IS_ENABLED(CONFIG_SERIAL_TEGRA_TCU_CONSOLE)
276 unregister_console(&tcu->console);
277#endif
278 mbox_free_channel(tcu->rx);
279 uart_remove_one_port(&tcu->driver, &tcu->port);
280 uart_unregister_driver(&tcu->driver);
281 mbox_free_channel(tcu->tx);
282}
283
284static const struct of_device_id tegra_tcu_match[] = {
285 { .compatible = "nvidia,tegra194-tcu" },
286 { }
287};
288MODULE_DEVICE_TABLE(of, tegra_tcu_match);
289
290static struct platform_driver tegra_tcu_driver = {
291 .driver = {
292 .name = "tegra-tcu",
293 .of_match_table = tegra_tcu_match,
294 },
295 .probe = tegra_tcu_probe,
296 .remove = tegra_tcu_remove,
297};
298module_platform_driver(tegra_tcu_driver);
299
300MODULE_AUTHOR("Mikko Perttunen <mperttunen@nvidia.com>");
301MODULE_LICENSE("GPL v2");
302MODULE_DESCRIPTION("NVIDIA Tegra Combined UART driver");