1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Copyright (C) 2004-2006 Atmel Corporation
4 *
5 * Modified to support C structur SoC access by
6 * Andreas Bießmann <biessmann@corscience.de>
7 */
8 #include <common.h>
9 #include <clk.h>
10 #include <dm.h>
11 #include <errno.h>
12 #include <malloc.h>
13 #include <watchdog.h>
14 #include <serial.h>
15 #include <debug_uart.h>
16 #include <asm/global_data.h>
17 #include <linux/compiler.h>
18 #include <linux/delay.h>
19
20 #include <asm/io.h>
21 #if CONFIG_IS_ENABLED(DM_SERIAL)
22 #include <asm/arch/atmel_serial.h>
23 #endif
24 #include <asm/arch/clk.h>
25 #include <asm/arch/hardware.h>
26
27 #include "atmel_usart.h"
28
29 DECLARE_GLOBAL_DATA_PTR;
30
31 #if !CONFIG_IS_ENABLED(DM_SERIAL)
atmel_serial_setbrg_internal(atmel_usart3_t * usart,int id,int baudrate)32 static void atmel_serial_setbrg_internal(atmel_usart3_t *usart, int id,
33 int baudrate)
34 {
35 unsigned long divisor;
36 unsigned long usart_hz;
37
38 /*
39 * Master Clock
40 * Baud Rate = --------------
41 * 16 * CD
42 */
43 usart_hz = get_usart_clk_rate(id);
44 divisor = (usart_hz / 16 + baudrate / 2) / baudrate;
45 writel(USART3_BF(CD, divisor), &usart->brgr);
46 }
47
atmel_serial_init_internal(atmel_usart3_t * usart)48 static void atmel_serial_init_internal(atmel_usart3_t *usart)
49 {
50 /*
51 * Just in case: drain transmitter register
52 * 1000us is enough for baudrate >= 9600
53 */
54 if (!(readl(&usart->csr) & USART3_BIT(TXEMPTY)))
55 __udelay(1000);
56
57 writel(USART3_BIT(RSTRX) | USART3_BIT(RSTTX), &usart->cr);
58 }
59
atmel_serial_activate(atmel_usart3_t * usart)60 static void atmel_serial_activate(atmel_usart3_t *usart)
61 {
62 writel((USART3_BF(USART_MODE, USART3_USART_MODE_NORMAL)
63 | USART3_BF(USCLKS, USART3_USCLKS_MCK)
64 | USART3_BF(CHRL, USART3_CHRL_8)
65 | USART3_BF(PAR, USART3_PAR_NONE)
66 | USART3_BF(NBSTOP, USART3_NBSTOP_1)),
67 &usart->mr);
68 writel(USART3_BIT(RXEN) | USART3_BIT(TXEN), &usart->cr);
69 /* 100us is enough for the new settings to be settled */
70 __udelay(100);
71 }
72
atmel_serial_setbrg(void)73 static void atmel_serial_setbrg(void)
74 {
75 atmel_serial_setbrg_internal((atmel_usart3_t *)CFG_USART_BASE,
76 CFG_USART_ID, gd->baudrate);
77 }
78
atmel_serial_init(void)79 static int atmel_serial_init(void)
80 {
81 atmel_usart3_t *usart = (atmel_usart3_t *)CFG_USART_BASE;
82
83 atmel_serial_init_internal(usart);
84 serial_setbrg();
85 atmel_serial_activate(usart);
86
87 return 0;
88 }
89
atmel_serial_putc(char c)90 static void atmel_serial_putc(char c)
91 {
92 atmel_usart3_t *usart = (atmel_usart3_t *)CFG_USART_BASE;
93
94 if (c == '\n')
95 serial_putc('\r');
96
97 while (!(readl(&usart->csr) & USART3_BIT(TXRDY)));
98 writel(c, &usart->thr);
99 }
100
atmel_serial_getc(void)101 static int atmel_serial_getc(void)
102 {
103 atmel_usart3_t *usart = (atmel_usart3_t *)CFG_USART_BASE;
104
105 while (!(readl(&usart->csr) & USART3_BIT(RXRDY)))
106 schedule();
107 return readl(&usart->rhr);
108 }
109
atmel_serial_tstc(void)110 static int atmel_serial_tstc(void)
111 {
112 atmel_usart3_t *usart = (atmel_usart3_t *)CFG_USART_BASE;
113 return (readl(&usart->csr) & USART3_BIT(RXRDY)) != 0;
114 }
115
116 static struct serial_device atmel_serial_drv = {
117 .name = "atmel_serial",
118 .start = atmel_serial_init,
119 .stop = NULL,
120 .setbrg = atmel_serial_setbrg,
121 .putc = atmel_serial_putc,
122 .puts = default_serial_puts,
123 .getc = atmel_serial_getc,
124 .tstc = atmel_serial_tstc,
125 };
126
atmel_serial_initialize(void)127 void atmel_serial_initialize(void)
128 {
129 serial_register(&atmel_serial_drv);
130 }
131
default_serial_console(void)132 __weak struct serial_device *default_serial_console(void)
133 {
134 return &atmel_serial_drv;
135 }
136 #else
137 enum serial_clk_type {
138 CLK_TYPE_NORMAL = 0,
139 CLK_TYPE_DBGU,
140 };
141
142 struct atmel_serial_priv {
143 atmel_usart3_t *usart;
144 ulong usart_clk_rate;
145 };
146
_atmel_serial_set_brg(atmel_usart3_t * usart,ulong usart_clk_rate,int baudrate)147 static void _atmel_serial_set_brg(atmel_usart3_t *usart,
148 ulong usart_clk_rate, int baudrate)
149 {
150 unsigned long divisor;
151
152 divisor = (usart_clk_rate / 16 + baudrate / 2) / baudrate;
153 writel(USART3_BF(CD, divisor), &usart->brgr);
154 }
155
_atmel_serial_init(atmel_usart3_t * usart,ulong usart_clk_rate,int baudrate)156 void _atmel_serial_init(atmel_usart3_t *usart,
157 ulong usart_clk_rate, int baudrate)
158 {
159 writel(USART3_BIT(RXDIS) | USART3_BIT(TXDIS), &usart->cr);
160
161 writel((USART3_BF(USART_MODE, USART3_USART_MODE_NORMAL) |
162 USART3_BF(USCLKS, USART3_USCLKS_MCK) |
163 USART3_BF(CHRL, USART3_CHRL_8) |
164 USART3_BF(PAR, USART3_PAR_NONE) |
165 USART3_BF(NBSTOP, USART3_NBSTOP_1)), &usart->mr);
166
167 _atmel_serial_set_brg(usart, usart_clk_rate, baudrate);
168
169 writel(USART3_BIT(RSTRX) | USART3_BIT(RSTTX), &usart->cr);
170 writel(USART3_BIT(RXEN) | USART3_BIT(TXEN), &usart->cr);
171 }
172
atmel_serial_setbrg(struct udevice * dev,int baudrate)173 int atmel_serial_setbrg(struct udevice *dev, int baudrate)
174 {
175 struct atmel_serial_priv *priv = dev_get_priv(dev);
176
177 _atmel_serial_set_brg(priv->usart, priv->usart_clk_rate, baudrate);
178
179 return 0;
180 }
181
atmel_serial_getc(struct udevice * dev)182 static int atmel_serial_getc(struct udevice *dev)
183 {
184 struct atmel_serial_priv *priv = dev_get_priv(dev);
185
186 if (!(readl(&priv->usart->csr) & USART3_BIT(RXRDY)))
187 return -EAGAIN;
188
189 return readl(&priv->usart->rhr);
190 }
191
atmel_serial_putc(struct udevice * dev,const char ch)192 static int atmel_serial_putc(struct udevice *dev, const char ch)
193 {
194 struct atmel_serial_priv *priv = dev_get_priv(dev);
195
196 if (!(readl(&priv->usart->csr) & USART3_BIT(TXRDY)))
197 return -EAGAIN;
198
199 writel(ch, &priv->usart->thr);
200
201 return 0;
202 }
203
atmel_serial_pending(struct udevice * dev,bool input)204 static int atmel_serial_pending(struct udevice *dev, bool input)
205 {
206 struct atmel_serial_priv *priv = dev_get_priv(dev);
207 uint32_t csr = readl(&priv->usart->csr);
208
209 if (input)
210 return csr & USART3_BIT(RXRDY) ? 1 : 0;
211 else
212 return csr & USART3_BIT(TXEMPTY) ? 0 : 1;
213 }
214
215 static const struct dm_serial_ops atmel_serial_ops = {
216 .putc = atmel_serial_putc,
217 .pending = atmel_serial_pending,
218 .getc = atmel_serial_getc,
219 .setbrg = atmel_serial_setbrg,
220 };
221
222 #if defined(CONFIG_SPL_BUILD) && !defined(CONFIG_SPL_CLK)
atmel_serial_enable_clk(struct udevice * dev)223 static int atmel_serial_enable_clk(struct udevice *dev)
224 {
225 struct atmel_serial_priv *priv = dev_get_priv(dev);
226
227 /* Use fixed clock value in SPL */
228 priv->usart_clk_rate = CONFIG_SPL_UART_CLOCK;
229
230 return 0;
231 }
232 #else
atmel_serial_enable_clk(struct udevice * dev)233 static int atmel_serial_enable_clk(struct udevice *dev)
234 {
235 struct atmel_serial_priv *priv = dev_get_priv(dev);
236 struct clk clk;
237 ulong clk_rate;
238 int ret;
239
240 ret = clk_get_by_index(dev, 0, &clk);
241 if (ret)
242 return -EINVAL;
243
244 if (dev_get_driver_data(dev) == CLK_TYPE_NORMAL) {
245 ret = clk_enable(&clk);
246 if (ret)
247 return ret;
248 }
249
250 clk_rate = clk_get_rate(&clk);
251 if (!clk_rate)
252 return -EINVAL;
253
254 priv->usart_clk_rate = clk_rate;
255
256 clk_free(&clk);
257
258 return 0;
259 }
260 #endif
261
atmel_serial_probe(struct udevice * dev)262 static int atmel_serial_probe(struct udevice *dev)
263 {
264 struct atmel_serial_plat *plat = dev_get_plat(dev);
265 struct atmel_serial_priv *priv = dev_get_priv(dev);
266 int ret;
267 #if CONFIG_IS_ENABLED(OF_CONTROL)
268 fdt_addr_t addr_base;
269
270 addr_base = dev_read_addr(dev);
271 if (addr_base == FDT_ADDR_T_NONE)
272 return -ENODEV;
273
274 plat->base_addr = (uint32_t)addr_base;
275 #endif
276 priv->usart = (atmel_usart3_t *)plat->base_addr;
277
278 ret = atmel_serial_enable_clk(dev);
279 if (ret)
280 return ret;
281
282 _atmel_serial_init(priv->usart, priv->usart_clk_rate, gd->baudrate);
283
284 return 0;
285 }
286
287 #if CONFIG_IS_ENABLED(OF_CONTROL)
288 static const struct udevice_id atmel_serial_ids[] = {
289 {
290 .compatible = "atmel,at91sam9260-dbgu",
291 .data = CLK_TYPE_DBGU,
292 },
293 {
294 .compatible = "atmel,at91sam9260-usart",
295 .data = CLK_TYPE_NORMAL,
296 },
297 { }
298 };
299 #endif
300
301 U_BOOT_DRIVER(serial_atmel) = {
302 .name = "serial_atmel",
303 .id = UCLASS_SERIAL,
304 #if CONFIG_IS_ENABLED(OF_CONTROL)
305 .of_match = atmel_serial_ids,
306 .plat_auto = sizeof(struct atmel_serial_plat),
307 #endif
308 .probe = atmel_serial_probe,
309 .ops = &atmel_serial_ops,
310 #if !CONFIG_IS_ENABLED(OF_CONTROL)
311 .flags = DM_FLAG_PRE_RELOC,
312 #endif
313 .priv_auto = sizeof(struct atmel_serial_priv),
314 };
315 #endif
316
317 #ifdef CONFIG_DEBUG_UART_ATMEL
_debug_uart_init(void)318 static inline void _debug_uart_init(void)
319 {
320 atmel_usart3_t *usart = (atmel_usart3_t *)CONFIG_VAL(DEBUG_UART_BASE);
321
322 _atmel_serial_init(usart, CONFIG_DEBUG_UART_CLOCK, CONFIG_BAUDRATE);
323 }
324
_debug_uart_putc(int ch)325 static inline void _debug_uart_putc(int ch)
326 {
327 atmel_usart3_t *usart = (atmel_usart3_t *)CONFIG_VAL(DEBUG_UART_BASE);
328
329 while (!(readl(&usart->csr) & USART3_BIT(TXRDY)))
330 ;
331
332 writel(ch, &usart->thr);
333 }
334
335 DEBUG_UART_FUNCS
336 #endif
337