xref: /openbmc/linux/arch/arm/mach-omap1/serial.c (revision e3b9f1e8)
1 /*
2  * linux/arch/arm/mach-omap1/serial.c
3  *
4  * OMAP1 serial support.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  */
10 #include <linux/gpio.h>
11 #include <linux/module.h>
12 #include <linux/kernel.h>
13 #include <linux/init.h>
14 #include <linux/irq.h>
15 #include <linux/delay.h>
16 #include <linux/serial.h>
17 #include <linux/tty.h>
18 #include <linux/serial_8250.h>
19 #include <linux/serial_reg.h>
20 #include <linux/clk.h>
21 #include <linux/io.h>
22 
23 #include <asm/mach-types.h>
24 
25 #include <mach/mux.h>
26 
27 #include "pm.h"
28 #include "soc.h"
29 
30 static struct clk * uart1_ck;
31 static struct clk * uart2_ck;
32 static struct clk * uart3_ck;
33 
34 static inline unsigned int omap_serial_in(struct plat_serial8250_port *up,
35 					  int offset)
36 {
37 	offset <<= up->regshift;
38 	return (unsigned int)__raw_readb(up->membase + offset);
39 }
40 
41 static inline void omap_serial_outp(struct plat_serial8250_port *p, int offset,
42 				    int value)
43 {
44 	offset <<= p->regshift;
45 	__raw_writeb(value, p->membase + offset);
46 }
47 
48 /*
49  * Internal UARTs need to be initialized for the 8250 autoconfig to work
50  * properly. Note that the TX watermark initialization may not be needed
51  * once the 8250.c watermark handling code is merged.
52  */
53 static void __init omap_serial_reset(struct plat_serial8250_port *p)
54 {
55 	omap_serial_outp(p, UART_OMAP_MDR1,
56 			UART_OMAP_MDR1_DISABLE);	/* disable UART */
57 	omap_serial_outp(p, UART_OMAP_SCR, 0x08);	/* TX watermark */
58 	omap_serial_outp(p, UART_OMAP_MDR1,
59 			UART_OMAP_MDR1_16X_MODE);	/* enable UART */
60 
61 	if (!cpu_is_omap15xx()) {
62 		omap_serial_outp(p, UART_OMAP_SYSC, 0x01);
63 		while (!(omap_serial_in(p, UART_OMAP_SYSC) & 0x01));
64 	}
65 }
66 
67 static struct plat_serial8250_port serial_platform_data[] = {
68 	{
69 		.mapbase	= OMAP1_UART1_BASE,
70 		.irq		= INT_UART1,
71 		.flags		= UPF_BOOT_AUTOCONF,
72 		.iotype		= UPIO_MEM,
73 		.regshift	= 2,
74 		.uartclk	= OMAP16XX_BASE_BAUD * 16,
75 	},
76 	{
77 		.mapbase	= OMAP1_UART2_BASE,
78 		.irq		= INT_UART2,
79 		.flags		= UPF_BOOT_AUTOCONF,
80 		.iotype		= UPIO_MEM,
81 		.regshift	= 2,
82 		.uartclk	= OMAP16XX_BASE_BAUD * 16,
83 	},
84 	{
85 		.mapbase	= OMAP1_UART3_BASE,
86 		.irq		= INT_UART3,
87 		.flags		= UPF_BOOT_AUTOCONF,
88 		.iotype		= UPIO_MEM,
89 		.regshift	= 2,
90 		.uartclk	= OMAP16XX_BASE_BAUD * 16,
91 	},
92 	{ },
93 };
94 
95 static struct platform_device serial_device = {
96 	.name			= "serial8250",
97 	.id			= PLAT8250_DEV_PLATFORM,
98 	.dev			= {
99 		.platform_data	= serial_platform_data,
100 	},
101 };
102 
103 /*
104  * Note that on Innovator-1510 UART2 pins conflict with USB2.
105  * By default UART2 does not work on Innovator-1510 if you have
106  * USB OHCI enabled. To use UART2, you must disable USB2 first.
107  */
108 void __init omap_serial_init(void)
109 {
110 	int i;
111 
112 	if (cpu_is_omap7xx()) {
113 		serial_platform_data[0].regshift = 0;
114 		serial_platform_data[1].regshift = 0;
115 		serial_platform_data[0].irq = INT_7XX_UART_MODEM_1;
116 		serial_platform_data[1].irq = INT_7XX_UART_MODEM_IRDA_2;
117 	}
118 
119 	if (cpu_is_omap15xx()) {
120 		serial_platform_data[0].uartclk = OMAP1510_BASE_BAUD * 16;
121 		serial_platform_data[1].uartclk = OMAP1510_BASE_BAUD * 16;
122 		serial_platform_data[2].uartclk = OMAP1510_BASE_BAUD * 16;
123 	}
124 
125 	for (i = 0; i < ARRAY_SIZE(serial_platform_data) - 1; i++) {
126 
127 		/* Don't look at UARTs higher than 2 for omap7xx */
128 		if (cpu_is_omap7xx() && i > 1) {
129 			serial_platform_data[i].membase = NULL;
130 			serial_platform_data[i].mapbase = 0;
131 			continue;
132 		}
133 
134 		/* Static mapping, never released */
135 		serial_platform_data[i].membase =
136 			ioremap(serial_platform_data[i].mapbase, SZ_2K);
137 		if (!serial_platform_data[i].membase) {
138 			printk(KERN_ERR "Could not ioremap uart%i\n", i);
139 			continue;
140 		}
141 		switch (i) {
142 		case 0:
143 			uart1_ck = clk_get(NULL, "uart1_ck");
144 			if (IS_ERR(uart1_ck))
145 				printk("Could not get uart1_ck\n");
146 			else {
147 				clk_enable(uart1_ck);
148 				if (cpu_is_omap15xx())
149 					clk_set_rate(uart1_ck, 12000000);
150 			}
151 			break;
152 		case 1:
153 			uart2_ck = clk_get(NULL, "uart2_ck");
154 			if (IS_ERR(uart2_ck))
155 				printk("Could not get uart2_ck\n");
156 			else {
157 				clk_enable(uart2_ck);
158 				if (cpu_is_omap15xx())
159 					clk_set_rate(uart2_ck, 12000000);
160 				else
161 					clk_set_rate(uart2_ck, 48000000);
162 			}
163 			break;
164 		case 2:
165 			uart3_ck = clk_get(NULL, "uart3_ck");
166 			if (IS_ERR(uart3_ck))
167 				printk("Could not get uart3_ck\n");
168 			else {
169 				clk_enable(uart3_ck);
170 				if (cpu_is_omap15xx())
171 					clk_set_rate(uart3_ck, 12000000);
172 			}
173 			break;
174 		}
175 		omap_serial_reset(&serial_platform_data[i]);
176 	}
177 }
178 
179 #ifdef CONFIG_OMAP_SERIAL_WAKE
180 
181 static irqreturn_t omap_serial_wake_interrupt(int irq, void *dev_id)
182 {
183 	/* Need to do something with serial port right after wake-up? */
184 	return IRQ_HANDLED;
185 }
186 
187 /*
188  * Reroutes serial RX lines to GPIO lines for the duration of
189  * sleep to allow waking up the device from serial port even
190  * in deep sleep.
191  */
192 void omap_serial_wake_trigger(int enable)
193 {
194 	if (!cpu_is_omap16xx())
195 		return;
196 
197 	if (uart1_ck != NULL) {
198 		if (enable)
199 			omap_cfg_reg(V14_16XX_GPIO37);
200 		else
201 			omap_cfg_reg(V14_16XX_UART1_RX);
202 	}
203 	if (uart2_ck != NULL) {
204 		if (enable)
205 			omap_cfg_reg(R9_16XX_GPIO18);
206 		else
207 			omap_cfg_reg(R9_16XX_UART2_RX);
208 	}
209 	if (uart3_ck != NULL) {
210 		if (enable)
211 			omap_cfg_reg(L14_16XX_GPIO49);
212 		else
213 			omap_cfg_reg(L14_16XX_UART3_RX);
214 	}
215 }
216 
217 static void __init omap_serial_set_port_wakeup(int gpio_nr)
218 {
219 	int ret;
220 
221 	ret = gpio_request(gpio_nr, "UART wake");
222 	if (ret < 0) {
223 		printk(KERN_ERR "Could not request UART wake GPIO: %i\n",
224 		       gpio_nr);
225 		return;
226 	}
227 	gpio_direction_input(gpio_nr);
228 	ret = request_irq(gpio_to_irq(gpio_nr), &omap_serial_wake_interrupt,
229 			  IRQF_TRIGGER_RISING, "serial wakeup", NULL);
230 	if (ret) {
231 		gpio_free(gpio_nr);
232 		printk(KERN_ERR "No interrupt for UART wake GPIO: %i\n",
233 		       gpio_nr);
234 		return;
235 	}
236 	enable_irq_wake(gpio_to_irq(gpio_nr));
237 }
238 
239 int __init omap_serial_wakeup_init(void)
240 {
241 	if (!cpu_is_omap16xx())
242 		return 0;
243 
244 	if (uart1_ck != NULL)
245 		omap_serial_set_port_wakeup(37);
246 	if (uart2_ck != NULL)
247 		omap_serial_set_port_wakeup(18);
248 	if (uart3_ck != NULL)
249 		omap_serial_set_port_wakeup(49);
250 
251 	return 0;
252 }
253 
254 #endif	/* CONFIG_OMAP_SERIAL_WAKE */
255 
256 static int __init omap_init(void)
257 {
258 	if (!cpu_class_is_omap1())
259 		return -ENODEV;
260 
261 	return platform_device_register(&serial_device);
262 }
263 arch_initcall(omap_init);
264