1 /*
2 * arch/arm/mach-omap2/serial.c
3 *
4 * OMAP2 serial support.
5 *
6 * Copyright (C) 2005-2008 Nokia Corporation
7 * Author: Paul Mundt <paul.mundt@nokia.com>
8 *
9 * Major rework for PM support by Kevin Hilman
10 *
11 * Based off of arch/arm/mach-omap/omap1/serial.c
12 *
13 * Copyright (C) 2009 Texas Instruments
14 * Added OMAP4 support - Santosh Shilimkar <santosh.shilimkar@ti.com
15 *
16 * This file is subject to the terms and conditions of the GNU General Public
17 * License. See the file "COPYING" in the main directory of this archive
18 * for more details.
19 */
20 #include <linux/kernel.h>
21 #include <linux/init.h>
22 #include <linux/clk.h>
23 #include <linux/io.h>
24 #include <linux/delay.h>
25 #include <linux/platform_device.h>
26 #include <linux/slab.h>
27 #include <linux/pm_runtime.h>
28 #include <linux/console.h>
29 #include <linux/omap-dma.h>
30 #include <linux/platform_data/serial-omap.h>
31
32 #include "common.h"
33 #include "omap_hwmod.h"
34 #include "omap_device.h"
35 #include "omap-pm.h"
36 #include "soc.h"
37 #include "prm2xxx_3xxx.h"
38 #include "pm.h"
39 #include "cm2xxx_3xxx.h"
40 #include "prm-regbits-34xx.h"
41 #include "control.h"
42 #include "mux.h"
43 #include "serial.h"
44
45 /*
46 * NOTE: By default the serial auto_suspend timeout is disabled as it causes
47 * lost characters over the serial ports. This means that the UART clocks will
48 * stay on until power/autosuspend_delay is set for the uart from sysfs.
49 * This also causes that any deeper omap sleep states are blocked.
50 */
51 #define DEFAULT_AUTOSUSPEND_DELAY -1
52
53 #define MAX_UART_HWMOD_NAME_LEN 16
54
55 struct omap_uart_state {
56 int num;
57
58 struct list_head node;
59 struct omap_hwmod *oh;
60 struct omap_device_pad default_omap_uart_pads[2];
61 };
62
63 static LIST_HEAD(uart_list);
64 static u8 num_uarts;
65 static u8 console_uart_id = -1;
66 static u8 uart_debug;
67
68 #define DEFAULT_RXDMA_POLLRATE 1 /* RX DMA polling rate (us) */
69 #define DEFAULT_RXDMA_BUFSIZE 4096 /* RX DMA buffer size */
70 #define DEFAULT_RXDMA_TIMEOUT (3 * HZ)/* RX DMA timeout (jiffies) */
71
72 static struct omap_uart_port_info omap_serial_default_info[] __initdata = {
73 {
74 .dma_enabled = false,
75 .dma_rx_buf_size = DEFAULT_RXDMA_BUFSIZE,
76 .dma_rx_poll_rate = DEFAULT_RXDMA_POLLRATE,
77 .dma_rx_timeout = DEFAULT_RXDMA_TIMEOUT,
78 .autosuspend_timeout = DEFAULT_AUTOSUSPEND_DELAY,
79 },
80 };
81
82 #ifdef CONFIG_PM
omap_uart_enable_wakeup(struct device * dev,bool enable)83 static void omap_uart_enable_wakeup(struct device *dev, bool enable)
84 {
85 struct platform_device *pdev = to_platform_device(dev);
86 struct omap_device *od = to_omap_device(pdev);
87
88 if (!od)
89 return;
90
91 if (enable)
92 omap_hwmod_enable_wakeup(od->hwmods[0]);
93 else
94 omap_hwmod_disable_wakeup(od->hwmods[0]);
95 }
96
97 #else
omap_uart_enable_wakeup(struct device * dev,bool enable)98 static void omap_uart_enable_wakeup(struct device *dev, bool enable)
99 {}
100 #endif /* CONFIG_PM */
101
102 #ifdef CONFIG_OMAP_MUX
103
104 #define OMAP_UART_DEFAULT_PAD_NAME_LEN 28
105 static char rx_pad_name[OMAP_UART_DEFAULT_PAD_NAME_LEN],
106 tx_pad_name[OMAP_UART_DEFAULT_PAD_NAME_LEN] __initdata;
107
108 static void __init
omap_serial_fill_uart_tx_rx_pads(struct omap_board_data * bdata,struct omap_uart_state * uart)109 omap_serial_fill_uart_tx_rx_pads(struct omap_board_data *bdata,
110 struct omap_uart_state *uart)
111 {
112 uart->default_omap_uart_pads[0].name = rx_pad_name;
113 uart->default_omap_uart_pads[0].flags = OMAP_DEVICE_PAD_REMUX |
114 OMAP_DEVICE_PAD_WAKEUP;
115 uart->default_omap_uart_pads[0].enable = OMAP_PIN_INPUT |
116 OMAP_MUX_MODE0;
117 uart->default_omap_uart_pads[0].idle = OMAP_PIN_INPUT | OMAP_MUX_MODE0;
118 uart->default_omap_uart_pads[1].name = tx_pad_name;
119 uart->default_omap_uart_pads[1].enable = OMAP_PIN_OUTPUT |
120 OMAP_MUX_MODE0;
121 bdata->pads = uart->default_omap_uart_pads;
122 bdata->pads_cnt = ARRAY_SIZE(uart->default_omap_uart_pads);
123 }
124
omap_serial_check_wakeup(struct omap_board_data * bdata,struct omap_uart_state * uart)125 static void __init omap_serial_check_wakeup(struct omap_board_data *bdata,
126 struct omap_uart_state *uart)
127 {
128 struct omap_mux_partition *tx_partition = NULL, *rx_partition = NULL;
129 struct omap_mux *rx_mux = NULL, *tx_mux = NULL;
130 char *rx_fmt, *tx_fmt;
131 int uart_nr = bdata->id + 1;
132
133 if (bdata->id != 2) {
134 rx_fmt = "uart%d_rx.uart%d_rx";
135 tx_fmt = "uart%d_tx.uart%d_tx";
136 } else {
137 rx_fmt = "uart%d_rx_irrx.uart%d_rx_irrx";
138 tx_fmt = "uart%d_tx_irtx.uart%d_tx_irtx";
139 }
140
141 snprintf(rx_pad_name, OMAP_UART_DEFAULT_PAD_NAME_LEN, rx_fmt,
142 uart_nr, uart_nr);
143 snprintf(tx_pad_name, OMAP_UART_DEFAULT_PAD_NAME_LEN, tx_fmt,
144 uart_nr, uart_nr);
145
146 if (omap_mux_get_by_name(rx_pad_name, &rx_partition, &rx_mux) >= 0 &&
147 omap_mux_get_by_name
148 (tx_pad_name, &tx_partition, &tx_mux) >= 0) {
149 u16 tx_mode, rx_mode;
150
151 tx_mode = omap_mux_read(tx_partition, tx_mux->reg_offset);
152 rx_mode = omap_mux_read(rx_partition, rx_mux->reg_offset);
153
154 /*
155 * Check if uart is used in default tx/rx mode i.e. in mux mode0
156 * if yes then configure rx pin for wake up capability
157 */
158 if (OMAP_MODE_UART(rx_mode) && OMAP_MODE_UART(tx_mode))
159 omap_serial_fill_uart_tx_rx_pads(bdata, uart);
160 }
161 }
162 #else
omap_serial_check_wakeup(struct omap_board_data * bdata,struct omap_uart_state * uart)163 static void __init omap_serial_check_wakeup(struct omap_board_data *bdata,
164 struct omap_uart_state *uart)
165 {
166 }
167 #endif
168
cmdline_find_option(char * str)169 static char *cmdline_find_option(char *str)
170 {
171 extern char *saved_command_line;
172
173 return strstr(saved_command_line, str);
174 }
175
omap_serial_early_init(void)176 static int __init omap_serial_early_init(void)
177 {
178 if (of_have_populated_dt())
179 return -ENODEV;
180
181 do {
182 char oh_name[MAX_UART_HWMOD_NAME_LEN];
183 struct omap_hwmod *oh;
184 struct omap_uart_state *uart;
185 char uart_name[MAX_UART_HWMOD_NAME_LEN];
186
187 snprintf(oh_name, MAX_UART_HWMOD_NAME_LEN,
188 "uart%d", num_uarts + 1);
189 oh = omap_hwmod_lookup(oh_name);
190 if (!oh)
191 break;
192
193 uart = kzalloc(sizeof(struct omap_uart_state), GFP_KERNEL);
194 if (WARN_ON(!uart))
195 return -ENODEV;
196
197 uart->oh = oh;
198 uart->num = num_uarts++;
199 list_add_tail(&uart->node, &uart_list);
200 snprintf(uart_name, MAX_UART_HWMOD_NAME_LEN,
201 "%s%d", OMAP_SERIAL_NAME, uart->num);
202
203 if (cmdline_find_option(uart_name)) {
204 console_uart_id = uart->num;
205
206 if (console_loglevel >= CONSOLE_LOGLEVEL_DEBUG) {
207 uart_debug = true;
208 pr_info("%s used as console in debug mode: uart%d clocks will not be gated",
209 uart_name, uart->num);
210 }
211 }
212 } while (1);
213
214 return 0;
215 }
216 omap_core_initcall(omap_serial_early_init);
217
218 /**
219 * omap_serial_init_port() - initialize single serial port
220 * @bdata: port specific board data pointer
221 * @info: platform specific data pointer
222 *
223 * This function initialies serial driver for given port only.
224 * Platforms can call this function instead of omap_serial_init()
225 * if they don't plan to use all available UARTs as serial ports.
226 *
227 * Don't mix calls to omap_serial_init_port() and omap_serial_init(),
228 * use only one of the two.
229 */
omap_serial_init_port(struct omap_board_data * bdata,struct omap_uart_port_info * info)230 void __init omap_serial_init_port(struct omap_board_data *bdata,
231 struct omap_uart_port_info *info)
232 {
233 struct omap_uart_state *uart;
234 struct omap_hwmod *oh;
235 struct platform_device *pdev;
236 void *pdata = NULL;
237 u32 pdata_size = 0;
238 char *name;
239 struct omap_uart_port_info omap_up;
240
241 if (WARN_ON(!bdata))
242 return;
243 if (WARN_ON(bdata->id < 0))
244 return;
245 if (WARN_ON(bdata->id >= num_uarts))
246 return;
247
248 list_for_each_entry(uart, &uart_list, node)
249 if (bdata->id == uart->num)
250 break;
251 if (!info)
252 info = omap_serial_default_info;
253
254 oh = uart->oh;
255 name = DRIVER_NAME;
256
257 omap_up.dma_enabled = info->dma_enabled;
258 omap_up.uartclk = OMAP24XX_BASE_BAUD * 16;
259 omap_up.flags = UPF_BOOT_AUTOCONF;
260 omap_up.get_context_loss_count = omap_pm_get_dev_context_loss_count;
261 omap_up.enable_wakeup = omap_uart_enable_wakeup;
262 omap_up.dma_rx_buf_size = info->dma_rx_buf_size;
263 omap_up.dma_rx_timeout = info->dma_rx_timeout;
264 omap_up.dma_rx_poll_rate = info->dma_rx_poll_rate;
265 omap_up.autosuspend_timeout = info->autosuspend_timeout;
266
267 pdata = &omap_up;
268 pdata_size = sizeof(struct omap_uart_port_info);
269
270 if (WARN_ON(!oh))
271 return;
272
273 pdev = omap_device_build(name, uart->num, oh, pdata, pdata_size);
274 if (IS_ERR(pdev)) {
275 WARN(1, "Could not build omap_device for %s: %s.\n", name,
276 oh->name);
277 return;
278 }
279
280 oh->mux = omap_hwmod_mux_init(bdata->pads, bdata->pads_cnt);
281
282 if (console_uart_id == bdata->id) {
283 omap_device_enable(pdev);
284 pm_runtime_set_active(&pdev->dev);
285 }
286
287 oh->dev_attr = uart;
288
289 if (((cpu_is_omap34xx() || cpu_is_omap44xx()) && bdata->pads)
290 && !uart_debug)
291 device_init_wakeup(&pdev->dev, true);
292 }
293
294 /**
295 * omap_serial_board_init() - initialize all supported serial ports
296 * @info: platform specific data pointer
297 *
298 * Initializes all available UARTs as serial ports. Platforms
299 * can call this function when they want to have default behaviour
300 * for serial ports (e.g initialize them all as serial ports).
301 */
omap_serial_board_init(struct omap_uart_port_info * info)302 void __init omap_serial_board_init(struct omap_uart_port_info *info)
303 {
304 struct omap_uart_state *uart;
305 struct omap_board_data bdata;
306
307 list_for_each_entry(uart, &uart_list, node) {
308 bdata.id = uart->num;
309 bdata.flags = 0;
310 bdata.pads = NULL;
311 bdata.pads_cnt = 0;
312
313 omap_serial_check_wakeup(&bdata, uart);
314
315 if (!info)
316 omap_serial_init_port(&bdata, NULL);
317 else
318 omap_serial_init_port(&bdata, &info[uart->num]);
319 }
320 }
321
322 /**
323 * omap_serial_init() - initialize all supported serial ports
324 *
325 * Initializes all available UARTs.
326 * Platforms can call this function when they want to have default behaviour
327 * for serial ports (e.g initialize them all as serial ports).
328 */
omap_serial_init(void)329 void __init omap_serial_init(void)
330 {
331 omap_serial_board_init(NULL);
332 }
333