Linux Kernel  3.7.1
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
serial.c
Go to the documentation of this file.
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 <[email protected]>
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 <[email protected]
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 
30 #include <plat/omap-serial.h>
31 #include "common.h"
32 #include <plat/dma.h>
33 #include <plat/omap_hwmod.h>
34 #include <plat/omap_device.h>
35 #include <plat/omap-pm.h>
36 #include <plat/serial.h>
37 
38 #include "prm2xxx_3xxx.h"
39 #include "pm.h"
40 #include "cm2xxx_3xxx.h"
41 #include "prm-regbits-34xx.h"
42 #include "control.h"
43 #include "mux.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 
56  int num;
57 
58  struct list_head node;
59  struct omap_hwmod *oh;
61 };
62 
63 static LIST_HEAD(uart_list);
64 static u8 num_uarts;
65 static u8 console_uart_id = -1;
66 static u8 no_console_suspend;
67 static u8 uart_debug;
68 
69 #define DEFAULT_RXDMA_POLLRATE 1 /* RX DMA polling rate (us) */
70 #define DEFAULT_RXDMA_BUFSIZE 4096 /* RX DMA buffer size */
71 #define DEFAULT_RXDMA_TIMEOUT (3 * HZ)/* RX DMA timeout (jiffies) */
72 
73 static struct omap_uart_port_info omap_serial_default_info[] __initdata = {
74  {
75  .dma_enabled = false,
76  .dma_rx_buf_size = DEFAULT_RXDMA_BUFSIZE,
77  .dma_rx_poll_rate = DEFAULT_RXDMA_POLLRATE,
78  .dma_rx_timeout = DEFAULT_RXDMA_TIMEOUT,
79  .autosuspend_timeout = DEFAULT_AUTOSUSPEND_DELAY,
80  },
81 };
82 
83 #ifdef CONFIG_PM
84 static void omap_uart_enable_wakeup(struct device *dev, bool enable)
85 {
87  struct omap_device *od = to_omap_device(pdev);
88 
89  if (!od)
90  return;
91 
92  if (enable)
94  else
96 }
97 
98 /*
99  * Errata i291: [UART]:Cannot Acknowledge Idle Requests
100  * in Smartidle Mode When Configured for DMA Operations.
101  * WA: configure uart in force idle mode.
102  */
103 static void omap_uart_set_noidle(struct device *dev)
104 {
105  struct platform_device *pdev = to_platform_device(dev);
106  struct omap_device *od = to_omap_device(pdev);
107 
109 }
110 
111 static void omap_uart_set_smartidle(struct device *dev)
112 {
113  struct platform_device *pdev = to_platform_device(dev);
114  struct omap_device *od = to_omap_device(pdev);
115  u8 idlemode;
116 
117  if (od->hwmods[0]->class->sysc->idlemodes & SIDLE_SMART_WKUP)
118  idlemode = HWMOD_IDLEMODE_SMART_WKUP;
119  else
120  idlemode = HWMOD_IDLEMODE_SMART;
121 
122  omap_hwmod_set_slave_idlemode(od->hwmods[0], idlemode);
123 }
124 
125 #else
126 static void omap_uart_enable_wakeup(struct device *dev, bool enable)
127 {}
128 static void omap_uart_set_noidle(struct device *dev) {}
129 static void omap_uart_set_smartidle(struct device *dev) {}
130 #endif /* CONFIG_PM */
131 
132 #ifdef CONFIG_OMAP_MUX
133 
134 #define OMAP_UART_DEFAULT_PAD_NAME_LEN 28
135 static char rx_pad_name[OMAP_UART_DEFAULT_PAD_NAME_LEN],
136  tx_pad_name[OMAP_UART_DEFAULT_PAD_NAME_LEN] __initdata;
137 
138 static void __init
139 omap_serial_fill_uart_tx_rx_pads(struct omap_board_data *bdata,
140  struct omap_uart_state *uart)
141 {
142  uart->default_omap_uart_pads[0].name = rx_pad_name;
145  uart->default_omap_uart_pads[0].enable = OMAP_PIN_INPUT |
148  uart->default_omap_uart_pads[1].name = tx_pad_name;
149  uart->default_omap_uart_pads[1].enable = OMAP_PIN_OUTPUT |
151  bdata->pads = uart->default_omap_uart_pads;
153 }
154 
155 static void __init omap_serial_check_wakeup(struct omap_board_data *bdata,
156  struct omap_uart_state *uart)
157 {
158  struct omap_mux_partition *tx_partition = NULL, *rx_partition = NULL;
159  struct omap_mux *rx_mux = NULL, *tx_mux = NULL;
160  char *rx_fmt, *tx_fmt;
161  int uart_nr = bdata->id + 1;
162 
163  if (bdata->id != 2) {
164  rx_fmt = "uart%d_rx.uart%d_rx";
165  tx_fmt = "uart%d_tx.uart%d_tx";
166  } else {
167  rx_fmt = "uart%d_rx_irrx.uart%d_rx_irrx";
168  tx_fmt = "uart%d_tx_irtx.uart%d_tx_irtx";
169  }
170 
171  snprintf(rx_pad_name, OMAP_UART_DEFAULT_PAD_NAME_LEN, rx_fmt,
172  uart_nr, uart_nr);
173  snprintf(tx_pad_name, OMAP_UART_DEFAULT_PAD_NAME_LEN, tx_fmt,
174  uart_nr, uart_nr);
175 
176  if (omap_mux_get_by_name(rx_pad_name, &rx_partition, &rx_mux) >= 0 &&
177  omap_mux_get_by_name
178  (tx_pad_name, &tx_partition, &tx_mux) >= 0) {
179  u16 tx_mode, rx_mode;
180 
181  tx_mode = omap_mux_read(tx_partition, tx_mux->reg_offset);
182  rx_mode = omap_mux_read(rx_partition, rx_mux->reg_offset);
183 
184  /*
185  * Check if uart is used in default tx/rx mode i.e. in mux mode0
186  * if yes then configure rx pin for wake up capability
187  */
188  if (OMAP_MODE_UART(rx_mode) && OMAP_MODE_UART(tx_mode))
189  omap_serial_fill_uart_tx_rx_pads(bdata, uart);
190  }
191 }
192 #else
193 static void __init omap_serial_check_wakeup(struct omap_board_data *bdata,
194  struct omap_uart_state *uart)
195 {
196 }
197 #endif
198 
199 static char *cmdline_find_option(char *str)
200 {
201  extern char *saved_command_line;
202 
203  return strstr(saved_command_line, str);
204 }
205 
206 static int __init omap_serial_early_init(void)
207 {
208  do {
209  char oh_name[MAX_UART_HWMOD_NAME_LEN];
210  struct omap_hwmod *oh;
211  struct omap_uart_state *uart;
212  char uart_name[MAX_UART_HWMOD_NAME_LEN];
213 
215  "uart%d", num_uarts + 1);
216  oh = omap_hwmod_lookup(oh_name);
217  if (!oh)
218  break;
219 
220  uart = kzalloc(sizeof(struct omap_uart_state), GFP_KERNEL);
221  if (WARN_ON(!uart))
222  return -ENODEV;
223 
224  uart->oh = oh;
225  uart->num = num_uarts++;
226  list_add_tail(&uart->node, &uart_list);
228  "%s%d", OMAP_SERIAL_NAME, uart->num);
229 
230  if (cmdline_find_option(uart_name)) {
231  console_uart_id = uart->num;
232 
233  if (console_loglevel >= 10) {
234  uart_debug = true;
235  pr_info("%s used as console in debug mode: uart%d clocks will not be gated",
236  uart_name, uart->num);
237  }
238 
239  if (cmdline_find_option("no_console_suspend"))
240  no_console_suspend = true;
241 
242  /*
243  * omap-uart can be used for earlyprintk logs
244  * So if omap-uart is used as console then prevent
245  * uart reset and idle to get logs from omap-uart
246  * until uart console driver is available to take
247  * care for console messages.
248  * Idling or resetting omap-uart while printing logs
249  * early boot logs can stall the boot-up.
250  */
252  }
253  } while (1);
254 
255  return 0;
256 }
257 core_initcall(omap_serial_early_init);
258 
272  struct omap_uart_port_info *info)
273 {
274  struct omap_uart_state *uart;
275  struct omap_hwmod *oh;
276  struct platform_device *pdev;
277  void *pdata = NULL;
278  u32 pdata_size = 0;
279  char *name;
280  struct omap_uart_port_info omap_up;
281 
282  if (WARN_ON(!bdata))
283  return;
284  if (WARN_ON(bdata->id < 0))
285  return;
286  if (WARN_ON(bdata->id >= num_uarts))
287  return;
288 
289  list_for_each_entry(uart, &uart_list, node)
290  if (bdata->id == uart->num)
291  break;
292  if (!info)
293  info = omap_serial_default_info;
294 
295  oh = uart->oh;
296  name = DRIVER_NAME;
297 
298  omap_up.dma_enabled = info->dma_enabled;
299  omap_up.uartclk = OMAP24XX_BASE_BAUD * 16;
300  omap_up.flags = UPF_BOOT_AUTOCONF;
302  omap_up.set_forceidle = omap_uart_set_smartidle;
303  omap_up.set_noidle = omap_uart_set_noidle;
304  omap_up.enable_wakeup = omap_uart_enable_wakeup;
305  omap_up.dma_rx_buf_size = info->dma_rx_buf_size;
306  omap_up.dma_rx_timeout = info->dma_rx_timeout;
307  omap_up.dma_rx_poll_rate = info->dma_rx_poll_rate;
309  omap_up.DTR_gpio = info->DTR_gpio;
310  omap_up.DTR_inverted = info->DTR_inverted;
311  omap_up.DTR_present = info->DTR_present;
312 
313  pdata = &omap_up;
314  pdata_size = sizeof(struct omap_uart_port_info);
315 
316  if (WARN_ON(!oh))
317  return;
318 
319  pdev = omap_device_build(name, uart->num, oh, pdata, pdata_size,
320  NULL, 0, false);
321  if (IS_ERR(pdev)) {
322  WARN(1, "Could not build omap_device for %s: %s.\n", name,
323  oh->name);
324  return;
325  }
326 
327  if ((console_uart_id == bdata->id) && no_console_suspend)
328  omap_device_disable_idle_on_suspend(pdev);
329 
330  oh->mux = omap_hwmod_mux_init(bdata->pads, bdata->pads_cnt);
331 
332  if (console_uart_id == bdata->id) {
333  omap_device_enable(pdev);
334  pm_runtime_set_active(&pdev->dev);
335  }
336 
337  oh->dev_attr = uart;
338 
339  if (((cpu_is_omap34xx() || cpu_is_omap44xx()) && bdata->pads)
340  && !uart_debug)
341  device_init_wakeup(&pdev->dev, true);
342 }
343 
353 {
354  struct omap_uart_state *uart;
355  struct omap_board_data bdata;
356 
357  list_for_each_entry(uart, &uart_list, node) {
358  bdata.id = uart->num;
359  bdata.flags = 0;
360  bdata.pads = NULL;
361  bdata.pads_cnt = 0;
362 
363  omap_serial_check_wakeup(&bdata, uart);
364 
365  if (!info)
366  omap_serial_init_port(&bdata, NULL);
367  else
368  omap_serial_init_port(&bdata, &info[uart->num]);
369  }
370 }
371 
380 {
382 }