xref: /openbmc/linux/arch/arm/mach-omap1/serial.c (revision 7dd65feb)
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 
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 <plat/board.h>
26 #include <plat/mux.h>
27 #include <mach/gpio.h>
28 #include <plat/fpga.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, 0x07);	/* disable UART */
56 	omap_serial_outp(p, UART_OMAP_SCR, 0x08);	/* TX watermark */
57 	omap_serial_outp(p, UART_OMAP_MDR1, 0x00);	/* enable UART */
58 
59 	if (!cpu_is_omap15xx()) {
60 		omap_serial_outp(p, UART_OMAP_SYSC, 0x01);
61 		while (!(omap_serial_in(p, UART_OMAP_SYSC) & 0x01));
62 	}
63 }
64 
65 static struct plat_serial8250_port serial_platform_data[] = {
66 	{
67 		.mapbase	= OMAP_UART1_BASE,
68 		.irq		= INT_UART1,
69 		.flags		= UPF_BOOT_AUTOCONF,
70 		.iotype		= UPIO_MEM,
71 		.regshift	= 2,
72 		.uartclk	= OMAP16XX_BASE_BAUD * 16,
73 	},
74 	{
75 		.mapbase	= OMAP_UART2_BASE,
76 		.irq		= INT_UART2,
77 		.flags		= UPF_BOOT_AUTOCONF,
78 		.iotype		= UPIO_MEM,
79 		.regshift	= 2,
80 		.uartclk	= OMAP16XX_BASE_BAUD * 16,
81 	},
82 	{
83 		.mapbase	= OMAP_UART3_BASE,
84 		.irq		= INT_UART3,
85 		.flags		= UPF_BOOT_AUTOCONF,
86 		.iotype		= UPIO_MEM,
87 		.regshift	= 2,
88 		.uartclk	= OMAP16XX_BASE_BAUD * 16,
89 	},
90 	{ },
91 };
92 
93 static struct platform_device serial_device = {
94 	.name			= "serial8250",
95 	.id			= PLAT8250_DEV_PLATFORM,
96 	.dev			= {
97 		.platform_data	= serial_platform_data,
98 	},
99 };
100 
101 /*
102  * Note that on Innovator-1510 UART2 pins conflict with USB2.
103  * By default UART2 does not work on Innovator-1510 if you have
104  * USB OHCI enabled. To use UART2, you must disable USB2 first.
105  */
106 void __init omap_serial_init(void)
107 {
108 	int i;
109 
110 	if (cpu_is_omap7xx()) {
111 		serial_platform_data[0].regshift = 0;
112 		serial_platform_data[1].regshift = 0;
113 		serial_platform_data[0].irq = INT_7XX_UART_MODEM_1;
114 		serial_platform_data[1].irq = INT_7XX_UART_MODEM_IRDA_2;
115 	}
116 
117 	if (cpu_is_omap15xx()) {
118 		serial_platform_data[0].uartclk = OMAP1510_BASE_BAUD * 16;
119 		serial_platform_data[1].uartclk = OMAP1510_BASE_BAUD * 16;
120 		serial_platform_data[2].uartclk = OMAP1510_BASE_BAUD * 16;
121 	}
122 
123 	for (i = 0; i < ARRAY_SIZE(serial_platform_data) - 1; i++) {
124 
125 		/* Static mapping, never released */
126 		serial_platform_data[i].membase =
127 			ioremap(serial_platform_data[i].mapbase, SZ_2K);
128 		if (!serial_platform_data[i].membase) {
129 			printk(KERN_ERR "Could not ioremap uart%i\n", i);
130 			continue;
131 		}
132 		switch (i) {
133 		case 0:
134 			uart1_ck = clk_get(NULL, "uart1_ck");
135 			if (IS_ERR(uart1_ck))
136 				printk("Could not get uart1_ck\n");
137 			else {
138 				clk_enable(uart1_ck);
139 				if (cpu_is_omap15xx())
140 					clk_set_rate(uart1_ck, 12000000);
141 			}
142 			break;
143 		case 1:
144 			uart2_ck = clk_get(NULL, "uart2_ck");
145 			if (IS_ERR(uart2_ck))
146 				printk("Could not get uart2_ck\n");
147 			else {
148 				clk_enable(uart2_ck);
149 				if (cpu_is_omap15xx())
150 					clk_set_rate(uart2_ck, 12000000);
151 				else
152 					clk_set_rate(uart2_ck, 48000000);
153 			}
154 			break;
155 		case 2:
156 			uart3_ck = clk_get(NULL, "uart3_ck");
157 			if (IS_ERR(uart3_ck))
158 				printk("Could not get uart3_ck\n");
159 			else {
160 				clk_enable(uart3_ck);
161 				if (cpu_is_omap15xx())
162 					clk_set_rate(uart3_ck, 12000000);
163 			}
164 			break;
165 		}
166 		omap_serial_reset(&serial_platform_data[i]);
167 	}
168 }
169 
170 #ifdef CONFIG_OMAP_SERIAL_WAKE
171 
172 static irqreturn_t omap_serial_wake_interrupt(int irq, void *dev_id)
173 {
174 	/* Need to do something with serial port right after wake-up? */
175 	return IRQ_HANDLED;
176 }
177 
178 /*
179  * Reroutes serial RX lines to GPIO lines for the duration of
180  * sleep to allow waking up the device from serial port even
181  * in deep sleep.
182  */
183 void omap_serial_wake_trigger(int enable)
184 {
185 	if (!cpu_is_omap16xx())
186 		return;
187 
188 	if (uart1_ck != NULL) {
189 		if (enable)
190 			omap_cfg_reg(V14_16XX_GPIO37);
191 		else
192 			omap_cfg_reg(V14_16XX_UART1_RX);
193 	}
194 	if (uart2_ck != NULL) {
195 		if (enable)
196 			omap_cfg_reg(R9_16XX_GPIO18);
197 		else
198 			omap_cfg_reg(R9_16XX_UART2_RX);
199 	}
200 	if (uart3_ck != NULL) {
201 		if (enable)
202 			omap_cfg_reg(L14_16XX_GPIO49);
203 		else
204 			omap_cfg_reg(L14_16XX_UART3_RX);
205 	}
206 }
207 
208 static void __init omap_serial_set_port_wakeup(int gpio_nr)
209 {
210 	int ret;
211 
212 	ret = gpio_request(gpio_nr, "UART wake");
213 	if (ret < 0) {
214 		printk(KERN_ERR "Could not request UART wake GPIO: %i\n",
215 		       gpio_nr);
216 		return;
217 	}
218 	gpio_direction_input(gpio_nr);
219 	ret = request_irq(gpio_to_irq(gpio_nr), &omap_serial_wake_interrupt,
220 			  IRQF_TRIGGER_RISING, "serial wakeup", NULL);
221 	if (ret) {
222 		gpio_free(gpio_nr);
223 		printk(KERN_ERR "No interrupt for UART wake GPIO: %i\n",
224 		       gpio_nr);
225 		return;
226 	}
227 	enable_irq_wake(gpio_to_irq(gpio_nr));
228 }
229 
230 static int __init omap_serial_wakeup_init(void)
231 {
232 	if (!cpu_is_omap16xx())
233 		return 0;
234 
235 	if (uart1_ck != NULL)
236 		omap_serial_set_port_wakeup(37);
237 	if (uart2_ck != NULL)
238 		omap_serial_set_port_wakeup(18);
239 	if (uart3_ck != NULL)
240 		omap_serial_set_port_wakeup(49);
241 
242 	return 0;
243 }
244 late_initcall(omap_serial_wakeup_init);
245 
246 #endif	/* CONFIG_OMAP_SERIAL_WAKE */
247 
248 static int __init omap_init(void)
249 {
250 	return platform_device_register(&serial_device);
251 }
252 arch_initcall(omap_init);
253