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
55 struct omap_uart_state {
56 int num;
57
58 struct list_head node;
59 struct omap_hwmod *oh;
60 };
61
62 static LIST_HEAD(uart_list);
63 static u8 num_uarts;
64 static u8 console_uart_id = -1;
65 static u8 no_console_suspend;
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 platform_device * pdev,bool enable)83 static void omap_uart_enable_wakeup(struct platform_device *pdev, bool enable)
84 {
85 struct omap_device *od = to_omap_device(pdev);
86
87 if (!od)
88 return;
89
90 if (enable)
91 omap_hwmod_enable_wakeup(od->hwmods[0]);
92 else
93 omap_hwmod_disable_wakeup(od->hwmods[0]);
94 }
95
96 /*
97 * Errata i291: [UART]:Cannot Acknowledge Idle Requests
98 * in Smartidle Mode When Configured for DMA Operations.
99 * WA: configure uart in force idle mode.
100 */
omap_uart_set_noidle(struct platform_device * pdev)101 static void omap_uart_set_noidle(struct platform_device *pdev)
102 {
103 struct omap_device *od = to_omap_device(pdev);
104
105 omap_hwmod_set_slave_idlemode(od->hwmods[0], HWMOD_IDLEMODE_NO);
106 }
107
omap_uart_set_smartidle(struct platform_device * pdev)108 static void omap_uart_set_smartidle(struct platform_device *pdev)
109 {
110 struct omap_device *od = to_omap_device(pdev);
111 u8 idlemode;
112
113 if (od->hwmods[0]->class->sysc->idlemodes & SIDLE_SMART_WKUP)
114 idlemode = HWMOD_IDLEMODE_SMART_WKUP;
115 else
116 idlemode = HWMOD_IDLEMODE_SMART;
117
118 omap_hwmod_set_slave_idlemode(od->hwmods[0], idlemode);
119 }
120
121 #else
omap_uart_enable_wakeup(struct platform_device * pdev,bool enable)122 static void omap_uart_enable_wakeup(struct platform_device *pdev, bool enable)
123 {}
omap_uart_set_noidle(struct platform_device * pdev)124 static void omap_uart_set_noidle(struct platform_device *pdev) {}
omap_uart_set_smartidle(struct platform_device * pdev)125 static void omap_uart_set_smartidle(struct platform_device *pdev) {}
126 #endif /* CONFIG_PM */
127
128 #ifdef CONFIG_OMAP_MUX
omap_serial_fill_default_pads(struct omap_board_data * bdata)129 static void omap_serial_fill_default_pads(struct omap_board_data *bdata)
130 {
131 }
132 #else
omap_serial_fill_default_pads(struct omap_board_data * bdata)133 static void omap_serial_fill_default_pads(struct omap_board_data *bdata) {}
134 #endif
135
cmdline_find_option(char * str)136 char *cmdline_find_option(char *str)
137 {
138 extern char *saved_command_line;
139
140 return strstr(saved_command_line, str);
141 }
142
omap_serial_early_init(void)143 static int __init omap_serial_early_init(void)
144 {
145 do {
146 char oh_name[MAX_UART_HWMOD_NAME_LEN];
147 struct omap_hwmod *oh;
148 struct omap_uart_state *uart;
149 char uart_name[MAX_UART_HWMOD_NAME_LEN];
150
151 snprintf(oh_name, MAX_UART_HWMOD_NAME_LEN,
152 "uart%d", num_uarts + 1);
153 oh = omap_hwmod_lookup(oh_name);
154 if (!oh)
155 break;
156
157 uart = kzalloc(sizeof(struct omap_uart_state), GFP_KERNEL);
158 if (WARN_ON(!uart))
159 return -ENODEV;
160
161 uart->oh = oh;
162 uart->num = num_uarts++;
163 list_add_tail(&uart->node, &uart_list);
164 snprintf(uart_name, MAX_UART_HWMOD_NAME_LEN,
165 "%s%d", OMAP_SERIAL_NAME, uart->num);
166
167 if (cmdline_find_option(uart_name)) {
168 console_uart_id = uart->num;
169
170 if (console_loglevel >= 10) {
171 uart_debug = true;
172 pr_info("%s used as console in debug mode"
173 " uart%d clocks will not be"
174 " gated", uart_name, uart->num);
175 }
176
177 if (cmdline_find_option("no_console_suspend"))
178 no_console_suspend = true;
179
180 /*
181 * omap-uart can be used for earlyprintk logs
182 * So if omap-uart is used as console then prevent
183 * uart reset and idle to get logs from omap-uart
184 * until uart console driver is available to take
185 * care for console messages.
186 * Idling or resetting omap-uart while printing logs
187 * early boot logs can stall the boot-up.
188 */
189 oh->flags |= HWMOD_INIT_NO_IDLE | HWMOD_INIT_NO_RESET;
190 }
191 } while (1);
192
193 return 0;
194 }
195 core_initcall(omap_serial_early_init);
196
197 /**
198 * omap_serial_init_port() - initialize single serial port
199 * @bdata: port specific board data pointer
200 * @info: platform specific data pointer
201 *
202 * This function initialies serial driver for given port only.
203 * Platforms can call this function instead of omap_serial_init()
204 * if they don't plan to use all available UARTs as serial ports.
205 *
206 * Don't mix calls to omap_serial_init_port() and omap_serial_init(),
207 * use only one of the two.
208 */
omap_serial_init_port(struct omap_board_data * bdata,struct omap_uart_port_info * info)209 void __init omap_serial_init_port(struct omap_board_data *bdata,
210 struct omap_uart_port_info *info)
211 {
212 struct omap_uart_state *uart;
213 struct omap_hwmod *oh;
214 struct platform_device *pdev;
215 void *pdata = NULL;
216 u32 pdata_size = 0;
217 char *name;
218 struct omap_uart_port_info omap_up;
219
220 if (WARN_ON(!bdata))
221 return;
222 if (WARN_ON(bdata->id < 0))
223 return;
224 if (WARN_ON(bdata->id >= num_uarts))
225 return;
226
227 list_for_each_entry(uart, &uart_list, node)
228 if (bdata->id == uart->num)
229 break;
230 if (!info)
231 info = omap_serial_default_info;
232
233 oh = uart->oh;
234 name = DRIVER_NAME;
235
236 omap_up.dma_enabled = info->dma_enabled;
237 omap_up.uartclk = OMAP24XX_BASE_BAUD * 16;
238 omap_up.flags = UPF_BOOT_AUTOCONF;
239 omap_up.get_context_loss_count = omap_pm_get_dev_context_loss_count;
240 omap_up.set_forceidle = omap_uart_set_smartidle;
241 omap_up.set_noidle = omap_uart_set_noidle;
242 omap_up.enable_wakeup = omap_uart_enable_wakeup;
243 omap_up.dma_rx_buf_size = info->dma_rx_buf_size;
244 omap_up.dma_rx_timeout = info->dma_rx_timeout;
245 omap_up.dma_rx_poll_rate = info->dma_rx_poll_rate;
246 omap_up.autosuspend_timeout = info->autosuspend_timeout;
247
248 /* Enable the MDR1 Errata i202 for OMAP2430/3xxx/44xx */
249 if (!cpu_is_omap2420() && !cpu_is_ti816x())
250 omap_up.errata |= UART_ERRATA_i202_MDR1_ACCESS;
251
252 /* Enable DMA Mode Force Idle Errata i291 for omap34xx/3630 */
253 if (cpu_is_omap34xx() || cpu_is_omap3630())
254 omap_up.errata |= UART_ERRATA_i291_DMA_FORCEIDLE;
255
256 pdata = &omap_up;
257 pdata_size = sizeof(struct omap_uart_port_info);
258
259 if (WARN_ON(!oh))
260 return;
261
262 pdev = omap_device_build(name, uart->num, oh, pdata, pdata_size,
263 NULL, 0, false);
264 WARN(IS_ERR(pdev), "Could not build omap_device for %s: %s.\n",
265 name, oh->name);
266
267 if ((console_uart_id == bdata->id) && no_console_suspend)
268 omap_device_disable_idle_on_suspend(pdev);
269
270 oh->mux = omap_hwmod_mux_init(bdata->pads, bdata->pads_cnt);
271
272 oh->dev_attr = uart;
273
274 if (((cpu_is_omap34xx() || cpu_is_omap44xx()) && bdata->pads)
275 && !uart_debug)
276 device_init_wakeup(&pdev->dev, true);
277 }
278
279 /**
280 * omap_serial_board_init() - initialize all supported serial ports
281 * @info: platform specific data pointer
282 *
283 * Initializes all available UARTs as serial ports. Platforms
284 * can call this function when they want to have default behaviour
285 * for serial ports (e.g initialize them all as serial ports).
286 */
omap_serial_board_init(struct omap_uart_port_info * info)287 void __init omap_serial_board_init(struct omap_uart_port_info *info)
288 {
289 struct omap_uart_state *uart;
290 struct omap_board_data bdata;
291
292 list_for_each_entry(uart, &uart_list, node) {
293 bdata.id = uart->num;
294 bdata.flags = 0;
295 bdata.pads = NULL;
296 bdata.pads_cnt = 0;
297
298 if (cpu_is_omap44xx() || cpu_is_omap34xx())
299 omap_serial_fill_default_pads(&bdata);
300
301 if (!info)
302 omap_serial_init_port(&bdata, NULL);
303 else
304 omap_serial_init_port(&bdata, &info[uart->num]);
305 }
306 }
307
308 /**
309 * omap_serial_init() - initialize all supported serial ports
310 *
311 * Initializes all available UARTs.
312 * Platforms can call this function when they want to have default behaviour
313 * for serial ports (e.g initialize them all as serial ports).
314 */
omap_serial_init(void)315 void __init omap_serial_init(void)
316 {
317 omap_serial_board_init(NULL);
318 }
319