xref: /openbmc/linux/arch/arm/mach-omap1/serial.c (revision 14474950)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * linux/arch/arm/mach-omap1/serial.c
4  *
5  * OMAP1 serial support.
6  */
7 #include <linux/gpio.h>
8 #include <linux/module.h>
9 #include <linux/kernel.h>
10 #include <linux/init.h>
11 #include <linux/irq.h>
12 #include <linux/delay.h>
13 #include <linux/serial.h>
14 #include <linux/tty.h>
15 #include <linux/serial_8250.h>
16 #include <linux/serial_reg.h>
17 #include <linux/clk.h>
18 #include <linux/io.h>
19 
20 #include <asm/mach-types.h>
21 
22 #include <mach/mux.h>
23 
24 #include "pm.h"
25 #include "soc.h"
26 
27 static struct clk * uart1_ck;
28 static struct clk * uart2_ck;
29 static struct clk * uart3_ck;
30 
31 static inline unsigned int omap_serial_in(struct plat_serial8250_port *up,
32 					  int offset)
33 {
34 	offset <<= up->regshift;
35 	return (unsigned int)__raw_readb(up->membase + offset);
36 }
37 
38 static inline void omap_serial_outp(struct plat_serial8250_port *p, int offset,
39 				    int value)
40 {
41 	offset <<= p->regshift;
42 	__raw_writeb(value, p->membase + offset);
43 }
44 
45 /*
46  * Internal UARTs need to be initialized for the 8250 autoconfig to work
47  * properly. Note that the TX watermark initialization may not be needed
48  * once the 8250.c watermark handling code is merged.
49  */
50 static void __init omap_serial_reset(struct plat_serial8250_port *p)
51 {
52 	omap_serial_outp(p, UART_OMAP_MDR1,
53 			UART_OMAP_MDR1_DISABLE);	/* disable UART */
54 	omap_serial_outp(p, UART_OMAP_SCR, 0x08);	/* TX watermark */
55 	omap_serial_outp(p, UART_OMAP_MDR1,
56 			UART_OMAP_MDR1_16X_MODE);	/* enable UART */
57 
58 	if (!cpu_is_omap15xx()) {
59 		omap_serial_outp(p, UART_OMAP_SYSC, 0x01);
60 		while (!(omap_serial_in(p, UART_OMAP_SYSC) & 0x01));
61 	}
62 }
63 
64 static struct plat_serial8250_port serial_platform_data[] = {
65 	{
66 		.mapbase	= OMAP1_UART1_BASE,
67 		.irq		= INT_UART1,
68 		.flags		= UPF_BOOT_AUTOCONF,
69 		.iotype		= UPIO_MEM,
70 		.regshift	= 2,
71 		.uartclk	= OMAP16XX_BASE_BAUD * 16,
72 	},
73 	{
74 		.mapbase	= OMAP1_UART2_BASE,
75 		.irq		= INT_UART2,
76 		.flags		= UPF_BOOT_AUTOCONF,
77 		.iotype		= UPIO_MEM,
78 		.regshift	= 2,
79 		.uartclk	= OMAP16XX_BASE_BAUD * 16,
80 	},
81 	{
82 		.mapbase	= OMAP1_UART3_BASE,
83 		.irq		= INT_UART3,
84 		.flags		= UPF_BOOT_AUTOCONF,
85 		.iotype		= UPIO_MEM,
86 		.regshift	= 2,
87 		.uartclk	= OMAP16XX_BASE_BAUD * 16,
88 	},
89 	{ },
90 };
91 
92 static struct platform_device serial_device = {
93 	.name			= "serial8250",
94 	.id			= PLAT8250_DEV_PLATFORM,
95 	.dev			= {
96 		.platform_data	= serial_platform_data,
97 	},
98 };
99 
100 /*
101  * Note that on Innovator-1510 UART2 pins conflict with USB2.
102  * By default UART2 does not work on Innovator-1510 if you have
103  * USB OHCI enabled. To use UART2, you must disable USB2 first.
104  */
105 void __init omap_serial_init(void)
106 {
107 	int i;
108 
109 	if (cpu_is_omap7xx()) {
110 		serial_platform_data[0].regshift = 0;
111 		serial_platform_data[1].regshift = 0;
112 		serial_platform_data[0].irq = INT_7XX_UART_MODEM_1;
113 		serial_platform_data[1].irq = INT_7XX_UART_MODEM_IRDA_2;
114 	}
115 
116 	if (cpu_is_omap15xx()) {
117 		serial_platform_data[0].uartclk = OMAP1510_BASE_BAUD * 16;
118 		serial_platform_data[1].uartclk = OMAP1510_BASE_BAUD * 16;
119 		serial_platform_data[2].uartclk = OMAP1510_BASE_BAUD * 16;
120 	}
121 
122 	for (i = 0; i < ARRAY_SIZE(serial_platform_data) - 1; i++) {
123 
124 		/* Don't look at UARTs higher than 2 for omap7xx */
125 		if (cpu_is_omap7xx() && i > 1) {
126 			serial_platform_data[i].membase = NULL;
127 			serial_platform_data[i].mapbase = 0;
128 			continue;
129 		}
130 
131 		/* Static mapping, never released */
132 		serial_platform_data[i].membase =
133 			ioremap(serial_platform_data[i].mapbase, SZ_2K);
134 		if (!serial_platform_data[i].membase) {
135 			printk(KERN_ERR "Could not ioremap uart%i\n", i);
136 			continue;
137 		}
138 		switch (i) {
139 		case 0:
140 			uart1_ck = clk_get(NULL, "uart1_ck");
141 			if (IS_ERR(uart1_ck))
142 				printk("Could not get uart1_ck\n");
143 			else {
144 				clk_enable(uart1_ck);
145 				if (cpu_is_omap15xx())
146 					clk_set_rate(uart1_ck, 12000000);
147 			}
148 			break;
149 		case 1:
150 			uart2_ck = clk_get(NULL, "uart2_ck");
151 			if (IS_ERR(uart2_ck))
152 				printk("Could not get uart2_ck\n");
153 			else {
154 				clk_enable(uart2_ck);
155 				if (cpu_is_omap15xx())
156 					clk_set_rate(uart2_ck, 12000000);
157 				else
158 					clk_set_rate(uart2_ck, 48000000);
159 			}
160 			break;
161 		case 2:
162 			uart3_ck = clk_get(NULL, "uart3_ck");
163 			if (IS_ERR(uart3_ck))
164 				printk("Could not get uart3_ck\n");
165 			else {
166 				clk_enable(uart3_ck);
167 				if (cpu_is_omap15xx())
168 					clk_set_rate(uart3_ck, 12000000);
169 			}
170 			break;
171 		}
172 		omap_serial_reset(&serial_platform_data[i]);
173 	}
174 }
175 
176 #ifdef CONFIG_OMAP_SERIAL_WAKE
177 
178 static irqreturn_t omap_serial_wake_interrupt(int irq, void *dev_id)
179 {
180 	/* Need to do something with serial port right after wake-up? */
181 	return IRQ_HANDLED;
182 }
183 
184 /*
185  * Reroutes serial RX lines to GPIO lines for the duration of
186  * sleep to allow waking up the device from serial port even
187  * in deep sleep.
188  */
189 void omap_serial_wake_trigger(int enable)
190 {
191 	if (!cpu_is_omap16xx())
192 		return;
193 
194 	if (uart1_ck != NULL) {
195 		if (enable)
196 			omap_cfg_reg(V14_16XX_GPIO37);
197 		else
198 			omap_cfg_reg(V14_16XX_UART1_RX);
199 	}
200 	if (uart2_ck != NULL) {
201 		if (enable)
202 			omap_cfg_reg(R9_16XX_GPIO18);
203 		else
204 			omap_cfg_reg(R9_16XX_UART2_RX);
205 	}
206 	if (uart3_ck != NULL) {
207 		if (enable)
208 			omap_cfg_reg(L14_16XX_GPIO49);
209 		else
210 			omap_cfg_reg(L14_16XX_UART3_RX);
211 	}
212 }
213 
214 static void __init omap_serial_set_port_wakeup(int gpio_nr)
215 {
216 	int ret;
217 
218 	ret = gpio_request(gpio_nr, "UART wake");
219 	if (ret < 0) {
220 		printk(KERN_ERR "Could not request UART wake GPIO: %i\n",
221 		       gpio_nr);
222 		return;
223 	}
224 	gpio_direction_input(gpio_nr);
225 	ret = request_irq(gpio_to_irq(gpio_nr), &omap_serial_wake_interrupt,
226 			  IRQF_TRIGGER_RISING, "serial wakeup", NULL);
227 	if (ret) {
228 		gpio_free(gpio_nr);
229 		printk(KERN_ERR "No interrupt for UART wake GPIO: %i\n",
230 		       gpio_nr);
231 		return;
232 	}
233 	enable_irq_wake(gpio_to_irq(gpio_nr));
234 }
235 
236 int __init omap_serial_wakeup_init(void)
237 {
238 	if (!cpu_is_omap16xx())
239 		return 0;
240 
241 	if (uart1_ck != NULL)
242 		omap_serial_set_port_wakeup(37);
243 	if (uart2_ck != NULL)
244 		omap_serial_set_port_wakeup(18);
245 	if (uart3_ck != NULL)
246 		omap_serial_set_port_wakeup(49);
247 
248 	return 0;
249 }
250 
251 #endif	/* CONFIG_OMAP_SERIAL_WAKE */
252 
253 static int __init omap_init(void)
254 {
255 	if (!cpu_class_is_omap1())
256 		return -ENODEV;
257 
258 	return platform_device_register(&serial_device);
259 }
260 arch_initcall(omap_init);
261