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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
30#include <plat/omap-serial.h>
31#include "common.h"
32#include <plat/board.h>
33#include <plat/dma.h>
34#include <plat/omap_hwmod.h>
35#include <plat/omap_device.h>
36#include <plat/omap-pm.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
55struct 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
63static LIST_HEAD(uart_list);
64static u8 num_uarts;
65static u8 console_uart_id = -1;
66static u8 no_console_suspend;
67static 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
73static 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
84static void omap_uart_enable_wakeup(struct platform_device *pdev, bool enable)
85{
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/*
98 * Errata i291: [UART]:Cannot Acknowledge Idle Requests
99 * in Smartidle Mode When Configured for DMA Operations.
100 * WA: configure uart in force idle mode.
101 */
102static void omap_uart_set_noidle(struct platform_device *pdev)
103{
104 struct omap_device *od = to_omap_device(pdev);
105
106 omap_hwmod_set_slave_idlemode(od->hwmods[0], HWMOD_IDLEMODE_NO);
107}
108
109static void omap_uart_set_smartidle(struct platform_device *pdev)
110{
111 struct omap_device *od = to_omap_device(pdev);
112 u8 idlemode;
113
114 if (od->hwmods[0]->class->sysc->idlemodes & SIDLE_SMART_WKUP)
115 idlemode = HWMOD_IDLEMODE_SMART_WKUP;
116 else
117 idlemode = HWMOD_IDLEMODE_SMART;
118
119 omap_hwmod_set_slave_idlemode(od->hwmods[0], idlemode);
120}
121
122#else
123static void omap_uart_enable_wakeup(struct platform_device *pdev, bool enable)
124{}
125static void omap_uart_set_noidle(struct platform_device *pdev) {}
126static void omap_uart_set_smartidle(struct platform_device *pdev) {}
127#endif /* CONFIG_PM */
128
129#ifdef CONFIG_OMAP_MUX
130
131#define OMAP_UART_DEFAULT_PAD_NAME_LEN 28
132static char rx_pad_name[OMAP_UART_DEFAULT_PAD_NAME_LEN],
133 tx_pad_name[OMAP_UART_DEFAULT_PAD_NAME_LEN] __initdata;
134
135static void __init
136omap_serial_fill_uart_tx_rx_pads(struct omap_board_data *bdata,
137 struct omap_uart_state *uart)
138{
139 uart->default_omap_uart_pads[0].name = rx_pad_name;
140 uart->default_omap_uart_pads[0].flags = OMAP_DEVICE_PAD_REMUX |
141 OMAP_DEVICE_PAD_WAKEUP;
142 uart->default_omap_uart_pads[0].enable = OMAP_PIN_INPUT |
143 OMAP_MUX_MODE0;
144 uart->default_omap_uart_pads[0].idle = OMAP_PIN_INPUT | OMAP_MUX_MODE0;
145 uart->default_omap_uart_pads[1].name = tx_pad_name;
146 uart->default_omap_uart_pads[1].enable = OMAP_PIN_OUTPUT |
147 OMAP_MUX_MODE0;
148 bdata->pads = uart->default_omap_uart_pads;
149 bdata->pads_cnt = ARRAY_SIZE(uart->default_omap_uart_pads);
150}
151
152static void __init omap_serial_check_wakeup(struct omap_board_data *bdata,
153 struct omap_uart_state *uart)
154{
155 struct omap_mux_partition *tx_partition = NULL, *rx_partition = NULL;
156 struct omap_mux *rx_mux = NULL, *tx_mux = NULL;
157 char *rx_fmt, *tx_fmt;
158 int uart_nr = bdata->id + 1;
159
160 if (bdata->id != 2) {
161 rx_fmt = "uart%d_rx.uart%d_rx";
162 tx_fmt = "uart%d_tx.uart%d_tx";
163 } else {
164 rx_fmt = "uart%d_rx_irrx.uart%d_rx_irrx";
165 tx_fmt = "uart%d_tx_irtx.uart%d_tx_irtx";
166 }
167
168 snprintf(rx_pad_name, OMAP_UART_DEFAULT_PAD_NAME_LEN, rx_fmt,
169 uart_nr, uart_nr);
170 snprintf(tx_pad_name, OMAP_UART_DEFAULT_PAD_NAME_LEN, tx_fmt,
171 uart_nr, uart_nr);
172
173 if (omap_mux_get_by_name(rx_pad_name, &rx_partition, &rx_mux) >= 0 &&
174 omap_mux_get_by_name
175 (tx_pad_name, &tx_partition, &tx_mux) >= 0) {
176 u16 tx_mode, rx_mode;
177
178 tx_mode = omap_mux_read(tx_partition, tx_mux->reg_offset);
179 rx_mode = omap_mux_read(rx_partition, rx_mux->reg_offset);
180
181 /*
182 * Check if uart is used in default tx/rx mode i.e. in mux mode0
183 * if yes then configure rx pin for wake up capability
184 */
185 if (OMAP_MODE_UART(rx_mode) && OMAP_MODE_UART(tx_mode))
186 omap_serial_fill_uart_tx_rx_pads(bdata, uart);
187 }
188}
189#else
190static void __init omap_serial_check_wakeup(struct omap_board_data *bdata,
191 struct omap_uart_state *uart)
192{
193}
194#endif
195
196static char *cmdline_find_option(char *str)
197{
198 extern char *saved_command_line;
199
200 return strstr(saved_command_line, str);
201}
202
203static int __init omap_serial_early_init(void)
204{
205 do {
206 char oh_name[MAX_UART_HWMOD_NAME_LEN];
207 struct omap_hwmod *oh;
208 struct omap_uart_state *uart;
209 char uart_name[MAX_UART_HWMOD_NAME_LEN];
210
211 snprintf(oh_name, MAX_UART_HWMOD_NAME_LEN,
212 "uart%d", num_uarts + 1);
213 oh = omap_hwmod_lookup(oh_name);
214 if (!oh)
215 break;
216
217 uart = kzalloc(sizeof(struct omap_uart_state), GFP_KERNEL);
218 if (WARN_ON(!uart))
219 return -ENODEV;
220
221 uart->oh = oh;
222 uart->num = num_uarts++;
223 list_add_tail(&uart->node, &uart_list);
224 snprintf(uart_name, MAX_UART_HWMOD_NAME_LEN,
225 "%s%d", OMAP_SERIAL_NAME, uart->num);
226
227 if (cmdline_find_option(uart_name)) {
228 console_uart_id = uart->num;
229
230 if (console_loglevel >= 10) {
231 uart_debug = true;
232 pr_info("%s used as console in debug mode"
233 " uart%d clocks will not be"
234 " gated", uart_name, uart->num);
235 }
236
237 if (cmdline_find_option("no_console_suspend"))
238 no_console_suspend = true;
239
240 /*
241 * omap-uart can be used for earlyprintk logs
242 * So if omap-uart is used as console then prevent
243 * uart reset and idle to get logs from omap-uart
244 * until uart console driver is available to take
245 * care for console messages.
246 * Idling or resetting omap-uart while printing logs
247 * early boot logs can stall the boot-up.
248 */
249 oh->flags |= HWMOD_INIT_NO_IDLE | HWMOD_INIT_NO_RESET;
250 }
251 } while (1);
252
253 return 0;
254}
255core_initcall(omap_serial_early_init);
256
257/**
258 * omap_serial_init_port() - initialize single serial port
259 * @bdata: port specific board data pointer
260 * @info: platform specific data pointer
261 *
262 * This function initialies serial driver for given port only.
263 * Platforms can call this function instead of omap_serial_init()
264 * if they don't plan to use all available UARTs as serial ports.
265 *
266 * Don't mix calls to omap_serial_init_port() and omap_serial_init(),
267 * use only one of the two.
268 */
269void __init omap_serial_init_port(struct omap_board_data *bdata,
270 struct omap_uart_port_info *info)
271{
272 struct omap_uart_state *uart;
273 struct omap_hwmod *oh;
274 struct platform_device *pdev;
275 void *pdata = NULL;
276 u32 pdata_size = 0;
277 char *name;
278 struct omap_uart_port_info omap_up;
279
280 if (WARN_ON(!bdata))
281 return;
282 if (WARN_ON(bdata->id < 0))
283 return;
284 if (WARN_ON(bdata->id >= num_uarts))
285 return;
286
287 list_for_each_entry(uart, &uart_list, node)
288 if (bdata->id == uart->num)
289 break;
290 if (!info)
291 info = omap_serial_default_info;
292
293 oh = uart->oh;
294 name = DRIVER_NAME;
295
296 omap_up.dma_enabled = info->dma_enabled;
297 omap_up.uartclk = OMAP24XX_BASE_BAUD * 16;
298 omap_up.flags = UPF_BOOT_AUTOCONF;
299 omap_up.get_context_loss_count = omap_pm_get_dev_context_loss_count;
300 omap_up.set_forceidle = omap_uart_set_smartidle;
301 omap_up.set_noidle = omap_uart_set_noidle;
302 omap_up.enable_wakeup = omap_uart_enable_wakeup;
303 omap_up.dma_rx_buf_size = info->dma_rx_buf_size;
304 omap_up.dma_rx_timeout = info->dma_rx_timeout;
305 omap_up.dma_rx_poll_rate = info->dma_rx_poll_rate;
306 omap_up.autosuspend_timeout = info->autosuspend_timeout;
307
308 pdata = &omap_up;
309 pdata_size = sizeof(struct omap_uart_port_info);
310
311 if (WARN_ON(!oh))
312 return;
313
314 pdev = omap_device_build(name, uart->num, oh, pdata, pdata_size,
315 NULL, 0, false);
316 WARN(IS_ERR(pdev), "Could not build omap_device for %s: %s.\n",
317 name, oh->name);
318
319 if ((console_uart_id == bdata->id) && no_console_suspend)
320 omap_device_disable_idle_on_suspend(pdev);
321
322 oh->mux = omap_hwmod_mux_init(bdata->pads, bdata->pads_cnt);
323
324 oh->dev_attr = uart;
325
326 if (((cpu_is_omap34xx() || cpu_is_omap44xx()) && bdata->pads)
327 && !uart_debug)
328 device_init_wakeup(&pdev->dev, true);
329}
330
331/**
332 * omap_serial_board_init() - initialize all supported serial ports
333 * @info: platform specific data pointer
334 *
335 * Initializes all available UARTs as serial ports. Platforms
336 * can call this function when they want to have default behaviour
337 * for serial ports (e.g initialize them all as serial ports).
338 */
339void __init omap_serial_board_init(struct omap_uart_port_info *info)
340{
341 struct omap_uart_state *uart;
342 struct omap_board_data bdata;
343
344 list_for_each_entry(uart, &uart_list, node) {
345 bdata.id = uart->num;
346 bdata.flags = 0;
347 bdata.pads = NULL;
348 bdata.pads_cnt = 0;
349
350 omap_serial_check_wakeup(&bdata, uart);
351
352 if (!info)
353 omap_serial_init_port(&bdata, NULL);
354 else
355 omap_serial_init_port(&bdata, &info[uart->num]);
356 }
357}
358
359/**
360 * omap_serial_init() - initialize all supported serial ports
361 *
362 * Initializes all available UARTs.
363 * Platforms can call this function when they want to have default behaviour
364 * for serial ports (e.g initialize them all as serial ports).
365 */
366void __init omap_serial_init(void)
367{
368 omap_serial_board_init(NULL);
369}