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/machine.h>
8 #include <linux/gpio/consumer.h>
9 #include <linux/module.h>
10 #include <linux/kernel.h>
11 #include <linux/init.h>
12 #include <linux/irq.h>
13 #include <linux/delay.h>
14 #include <linux/serial.h>
15 #include <linux/tty.h>
16 #include <linux/serial_8250.h>
17 #include <linux/serial_reg.h>
18 #include <linux/clk.h>
19 #include <linux/io.h>
20
21 #include <asm/mach-types.h>
22
23 #include "common.h"
24 #include "serial.h"
25 #include "mux.h"
26 #include "pm.h"
27 #include "soc.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_omap15xx()) {
112 serial_platform_data[0].uartclk = OMAP1510_BASE_BAUD * 16;
113 serial_platform_data[1].uartclk = OMAP1510_BASE_BAUD * 16;
114 serial_platform_data[2].uartclk = OMAP1510_BASE_BAUD * 16;
115 }
116
117 for (i = 0; i < ARRAY_SIZE(serial_platform_data) - 1; i++) {
118 /* Static mapping, never released */
119 serial_platform_data[i].membase =
120 ioremap(serial_platform_data[i].mapbase, SZ_2K);
121 if (!serial_platform_data[i].membase) {
122 printk(KERN_ERR "Could not ioremap uart%i\n", i);
123 continue;
124 }
125 switch (i) {
126 case 0:
127 uart1_ck = clk_get(NULL, "uart1_ck");
128 if (IS_ERR(uart1_ck))
129 printk("Could not get uart1_ck\n");
130 else {
131 clk_prepare_enable(uart1_ck);
132 if (cpu_is_omap15xx())
133 clk_set_rate(uart1_ck, 12000000);
134 }
135 break;
136 case 1:
137 uart2_ck = clk_get(NULL, "uart2_ck");
138 if (IS_ERR(uart2_ck))
139 printk("Could not get uart2_ck\n");
140 else {
141 clk_prepare_enable(uart2_ck);
142 if (cpu_is_omap15xx())
143 clk_set_rate(uart2_ck, 12000000);
144 else
145 clk_set_rate(uart2_ck, 48000000);
146 }
147 break;
148 case 2:
149 uart3_ck = clk_get(NULL, "uart3_ck");
150 if (IS_ERR(uart3_ck))
151 printk("Could not get uart3_ck\n");
152 else {
153 clk_prepare_enable(uart3_ck);
154 if (cpu_is_omap15xx())
155 clk_set_rate(uart3_ck, 12000000);
156 }
157 break;
158 }
159 omap_serial_reset(&serial_platform_data[i]);
160 }
161 }
162
163 #ifdef CONFIG_OMAP_SERIAL_WAKE
164
165 static irqreturn_t omap_serial_wake_interrupt(int irq, void *dev_id)
166 {
167 /* Need to do something with serial port right after wake-up? */
168 return IRQ_HANDLED;
169 }
170
171 /*
172 * Reroutes serial RX lines to GPIO lines for the duration of
173 * sleep to allow waking up the device from serial port even
174 * in deep sleep.
175 */
176 void omap_serial_wake_trigger(int enable)
177 {
178 if (!cpu_is_omap16xx())
179 return;
180
181 if (uart1_ck != NULL) {
182 if (enable)
183 omap_cfg_reg(V14_16XX_GPIO37);
184 else
185 omap_cfg_reg(V14_16XX_UART1_RX);
186 }
187 if (uart2_ck != NULL) {
188 if (enable)
189 omap_cfg_reg(R9_16XX_GPIO18);
190 else
191 omap_cfg_reg(R9_16XX_UART2_RX);
192 }
193 if (uart3_ck != NULL) {
194 if (enable)
195 omap_cfg_reg(L14_16XX_GPIO49);
196 else
197 omap_cfg_reg(L14_16XX_UART3_RX);
198 }
199 }
200
201 static void __init omap_serial_set_port_wakeup(int idx)
202 {
203 struct gpio_desc *d;
204 int ret;
205
206 d = gpiod_get_index(NULL, "wakeup", idx, GPIOD_IN);
207 if (IS_ERR(d)) {
208 pr_err("Unable to get UART wakeup GPIO descriptor\n");
209 return;
210 }
211 ret = request_irq(gpiod_to_irq(d), &omap_serial_wake_interrupt,
212 IRQF_TRIGGER_RISING, "serial wakeup", NULL);
213 if (ret) {
214 gpiod_put(d);
215 pr_err("No interrupt for UART%d wake GPIO\n", idx + 1);
216 return;
217 }
218 enable_irq_wake(gpiod_to_irq(d));
219 }
220
221
222 int __init omap_serial_wakeup_init(void)
223 {
224 if (!cpu_is_omap16xx())
225 return 0;
226
227 if (uart1_ck != NULL)
228 omap_serial_set_port_wakeup(0);
229 if (uart2_ck != NULL)
230 omap_serial_set_port_wakeup(1);
231 if (uart3_ck != NULL)
232 omap_serial_set_port_wakeup(2);
233
234 return 0;
235 }
236
237 #endif /* CONFIG_OMAP_SERIAL_WAKE */
238
239 static int __init omap_init(void)
240 {
241 if (!cpu_class_is_omap1())
242 return -ENODEV;
243
244 return platform_device_register(&serial_device);
245 }
246 arch_initcall(omap_init);
247
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