xref: /openbmc/linux/arch/arm/mach-omap1/serial.c (revision 12eb4683)
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 
29 static struct clk * uart1_ck;
30 static struct clk * uart2_ck;
31 static struct clk * uart3_ck;
32 
33 static inline unsigned int omap_serial_in(struct plat_serial8250_port *up,
34 					  int offset)
35 {
36 	offset <<= up->regshift;
37 	return (unsigned int)__raw_readb(up->membase + offset);
38 }
39 
40 static inline void omap_serial_outp(struct plat_serial8250_port *p, int offset,
41 				    int value)
42 {
43 	offset <<= p->regshift;
44 	__raw_writeb(value, p->membase + offset);
45 }
46 
47 /*
48  * Internal UARTs need to be initialized for the 8250 autoconfig to work
49  * properly. Note that the TX watermark initialization may not be needed
50  * once the 8250.c watermark handling code is merged.
51  */
52 static void __init omap_serial_reset(struct plat_serial8250_port *p)
53 {
54 	omap_serial_outp(p, UART_OMAP_MDR1,
55 			UART_OMAP_MDR1_DISABLE);	/* disable UART */
56 	omap_serial_outp(p, UART_OMAP_SCR, 0x08);	/* TX watermark */
57 	omap_serial_outp(p, UART_OMAP_MDR1,
58 			UART_OMAP_MDR1_16X_MODE);	/* enable UART */
59 
60 	if (!cpu_is_omap15xx()) {
61 		omap_serial_outp(p, UART_OMAP_SYSC, 0x01);
62 		while (!(omap_serial_in(p, UART_OMAP_SYSC) & 0x01));
63 	}
64 }
65 
66 static struct plat_serial8250_port serial_platform_data[] = {
67 	{
68 		.mapbase	= OMAP1_UART1_BASE,
69 		.irq		= INT_UART1,
70 		.flags		= UPF_BOOT_AUTOCONF,
71 		.iotype		= UPIO_MEM,
72 		.regshift	= 2,
73 		.uartclk	= OMAP16XX_BASE_BAUD * 16,
74 	},
75 	{
76 		.mapbase	= OMAP1_UART2_BASE,
77 		.irq		= INT_UART2,
78 		.flags		= UPF_BOOT_AUTOCONF,
79 		.iotype		= UPIO_MEM,
80 		.regshift	= 2,
81 		.uartclk	= OMAP16XX_BASE_BAUD * 16,
82 	},
83 	{
84 		.mapbase	= OMAP1_UART3_BASE,
85 		.irq		= INT_UART3,
86 		.flags		= UPF_BOOT_AUTOCONF,
87 		.iotype		= UPIO_MEM,
88 		.regshift	= 2,
89 		.uartclk	= OMAP16XX_BASE_BAUD * 16,
90 	},
91 	{ },
92 };
93 
94 static struct platform_device serial_device = {
95 	.name			= "serial8250",
96 	.id			= PLAT8250_DEV_PLATFORM,
97 	.dev			= {
98 		.platform_data	= serial_platform_data,
99 	},
100 };
101 
102 /*
103  * Note that on Innovator-1510 UART2 pins conflict with USB2.
104  * By default UART2 does not work on Innovator-1510 if you have
105  * USB OHCI enabled. To use UART2, you must disable USB2 first.
106  */
107 void __init omap_serial_init(void)
108 {
109 	int i;
110 
111 	if (cpu_is_omap7xx()) {
112 		serial_platform_data[0].regshift = 0;
113 		serial_platform_data[1].regshift = 0;
114 		serial_platform_data[0].irq = INT_7XX_UART_MODEM_1;
115 		serial_platform_data[1].irq = INT_7XX_UART_MODEM_IRDA_2;
116 	}
117 
118 	if (cpu_is_omap15xx()) {
119 		serial_platform_data[0].uartclk = OMAP1510_BASE_BAUD * 16;
120 		serial_platform_data[1].uartclk = OMAP1510_BASE_BAUD * 16;
121 		serial_platform_data[2].uartclk = OMAP1510_BASE_BAUD * 16;
122 	}
123 
124 	for (i = 0; i < ARRAY_SIZE(serial_platform_data) - 1; i++) {
125 
126 		/* Don't look at UARTs higher than 2 for omap7xx */
127 		if (cpu_is_omap7xx() && i > 1) {
128 			serial_platform_data[i].membase = NULL;
129 			serial_platform_data[i].mapbase = 0;
130 			continue;
131 		}
132 
133 		/* Static mapping, never released */
134 		serial_platform_data[i].membase =
135 			ioremap(serial_platform_data[i].mapbase, SZ_2K);
136 		if (!serial_platform_data[i].membase) {
137 			printk(KERN_ERR "Could not ioremap uart%i\n", i);
138 			continue;
139 		}
140 		switch (i) {
141 		case 0:
142 			uart1_ck = clk_get(NULL, "uart1_ck");
143 			if (IS_ERR(uart1_ck))
144 				printk("Could not get uart1_ck\n");
145 			else {
146 				clk_enable(uart1_ck);
147 				if (cpu_is_omap15xx())
148 					clk_set_rate(uart1_ck, 12000000);
149 			}
150 			break;
151 		case 1:
152 			uart2_ck = clk_get(NULL, "uart2_ck");
153 			if (IS_ERR(uart2_ck))
154 				printk("Could not get uart2_ck\n");
155 			else {
156 				clk_enable(uart2_ck);
157 				if (cpu_is_omap15xx())
158 					clk_set_rate(uart2_ck, 12000000);
159 				else
160 					clk_set_rate(uart2_ck, 48000000);
161 			}
162 			break;
163 		case 2:
164 			uart3_ck = clk_get(NULL, "uart3_ck");
165 			if (IS_ERR(uart3_ck))
166 				printk("Could not get uart3_ck\n");
167 			else {
168 				clk_enable(uart3_ck);
169 				if (cpu_is_omap15xx())
170 					clk_set_rate(uart3_ck, 12000000);
171 			}
172 			break;
173 		}
174 		omap_serial_reset(&serial_platform_data[i]);
175 	}
176 }
177 
178 #ifdef CONFIG_OMAP_SERIAL_WAKE
179 
180 static irqreturn_t omap_serial_wake_interrupt(int irq, void *dev_id)
181 {
182 	/* Need to do something with serial port right after wake-up? */
183 	return IRQ_HANDLED;
184 }
185 
186 /*
187  * Reroutes serial RX lines to GPIO lines for the duration of
188  * sleep to allow waking up the device from serial port even
189  * in deep sleep.
190  */
191 void omap_serial_wake_trigger(int enable)
192 {
193 	if (!cpu_is_omap16xx())
194 		return;
195 
196 	if (uart1_ck != NULL) {
197 		if (enable)
198 			omap_cfg_reg(V14_16XX_GPIO37);
199 		else
200 			omap_cfg_reg(V14_16XX_UART1_RX);
201 	}
202 	if (uart2_ck != NULL) {
203 		if (enable)
204 			omap_cfg_reg(R9_16XX_GPIO18);
205 		else
206 			omap_cfg_reg(R9_16XX_UART2_RX);
207 	}
208 	if (uart3_ck != NULL) {
209 		if (enable)
210 			omap_cfg_reg(L14_16XX_GPIO49);
211 		else
212 			omap_cfg_reg(L14_16XX_UART3_RX);
213 	}
214 }
215 
216 static void __init omap_serial_set_port_wakeup(int gpio_nr)
217 {
218 	int ret;
219 
220 	ret = gpio_request(gpio_nr, "UART wake");
221 	if (ret < 0) {
222 		printk(KERN_ERR "Could not request UART wake GPIO: %i\n",
223 		       gpio_nr);
224 		return;
225 	}
226 	gpio_direction_input(gpio_nr);
227 	ret = request_irq(gpio_to_irq(gpio_nr), &omap_serial_wake_interrupt,
228 			  IRQF_TRIGGER_RISING, "serial wakeup", NULL);
229 	if (ret) {
230 		gpio_free(gpio_nr);
231 		printk(KERN_ERR "No interrupt for UART wake GPIO: %i\n",
232 		       gpio_nr);
233 		return;
234 	}
235 	enable_irq_wake(gpio_to_irq(gpio_nr));
236 }
237 
238 int __init omap_serial_wakeup_init(void)
239 {
240 	if (!cpu_is_omap16xx())
241 		return 0;
242 
243 	if (uart1_ck != NULL)
244 		omap_serial_set_port_wakeup(37);
245 	if (uart2_ck != NULL)
246 		omap_serial_set_port_wakeup(18);
247 	if (uart3_ck != NULL)
248 		omap_serial_set_port_wakeup(49);
249 
250 	return 0;
251 }
252 
253 #endif	/* CONFIG_OMAP_SERIAL_WAKE */
254 
255 static int __init omap_init(void)
256 {
257 	if (!cpu_class_is_omap1())
258 		return -ENODEV;
259 
260 	return platform_device_register(&serial_device);
261 }
262 arch_initcall(omap_init);
263