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[karo-tx-linux.git] / arch / arm / mach-omap2 / serial.c
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
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
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
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
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
163 static void __init omap_serial_check_wakeup(struct omap_board_data *bdata,
164                 struct omap_uart_state *uart)
165 {
166 }
167 #endif
168
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
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  */
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  */
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  */
329 void __init omap_serial_init(void)
330 {
331         omap_serial_board_init(NULL);
332 }