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
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 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
72static 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
83static 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
98static 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
105static char rx_pad_name[OMAP_UART_DEFAULT_PAD_NAME_LEN],
106		tx_pad_name[OMAP_UART_DEFAULT_PAD_NAME_LEN] __initdata;
107
108static void  __init
109omap_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
125static 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
163static void __init omap_serial_check_wakeup(struct omap_board_data *bdata,
164		struct omap_uart_state *uart)
165{
166}
167#endif
168
169static char *cmdline_find_option(char *str)
170{
171	extern char *saved_command_line;
172
173	return strstr(saved_command_line, str);
174}
175
176static 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 >= 10) {
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}
216omap_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 */
230void __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 */
302void __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 */
329void __init omap_serial_init(void)
330{
331	omap_serial_board_init(NULL);
332}
333