要:
目前,市面上很多6410开发板都存在触摸屏抖动的问题,tiny6410也不例外,友善的解决方法是采用一线触摸,即在LCD板上,用一个单片机控制ADS7846芯片AD转换,再将数据通过单总线的方式与6410通讯。可是,我这里没有一线触摸板,于是就开始移植ADS7846驱动到tiny6410。
介绍:
可能有人会问,6410的触摸屏为什么会抖动呢,是不是滤波没做好,或者是硬件走线的原因?是不是硬件的原因,我无法验证。我尝试过通过滤波来改善,但效果一般。不说别的,我在单独测试AD的时候,发现在输入不变的情况下,AD采样的跳幅最大达到25(0~1024范围),可见,跳动还是很大的,这样的情况下,即使再滤波也只是浪费时间。
mini6410-ts.c触摸屏驱动见:
先说说我的硬件:
TS_PEN ----- GPN9 EINT9
TS_MISO ---- GPC0 MISO0
TS_MOSI ---- GPC2 MOSI0
TS_SCK ----- GPC1 SCK0
TS_CS ----- GPC3 CS0
这些端子在核心板的CON1上可以找到,我这里是用的IO模拟的SPI。
下面的开始介绍移植的过程,代码,我在下面会全部帖出来,里面注释也很详细,一般都能看明白。
1、复制/opt/FriendlyARM/mini6410/linux-2.6.38/drivers/input/touchscreen/mini6410-ts.c为mini6410-ads7846.c。
修改后,如下:
001 |
/* linux/drivers/input/touchscreen/s3c-ts.c |
002 |
* |
003 |
* This program is free software; you can redistribute it and/or modify |
004 |
* it under the terms of the GNU General Public License as published by |
005 |
* the Free Software Foundation; either version 2 of the License, or |
006 |
* (at your option) any later version. |
007 |
* |
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* This program is distributed in the hope that it will be useful, |
009 |
* but WITHOUT ANY WARRANTY; without even the implied warranty of |
010 |
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
011 |
* GNU General Public License for more details. |
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* |
013 |
* You should have received a copy of the GNU General Public License |
014 |
* along with this program; if not, write to the Free Software |
015 |
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
016 |
* |
017 |
* a misc driver for mini6410 touch screen |
018 |
* by FriendlyARM 2010 |
019 |
* |
020 |
* Based on following software: |
021 |
* |
022 |
** Copyright (c) 2004 Arnaud Patard <[email protected]> |
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** iPAQ H1940 touchscreen support |
024 |
** |
025 |
** ChangeLog |
026 |
** |
027 |
** 2004-09-05: Herbert Potzl <[email protected]> |
028 |
** - added clock (de-)allocation code |
029 |
** |
030 |
** 2005-03-06: Arnaud Patard <[email protected]> |
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** - h1940_ -> s3c24xx (this driver is now also used on the n30 |
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** machines :P) |
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** - Debug messages are now enabled with the config option |
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** TOUCHSCREEN_S3C_DEBUG |
035 |
** - Changed the way the value are read |
036 |
** - Input subsystem should now work |
037 |
** - Use ioremap and readl/writel |
038 |
** |
039 |
** 2005-03-23: Arnaud Patard <[email protected]> |
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** - Make use of some undocumented features of the touchscreen |
041 |
** controller |
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** |
043 |
** 2006-09-05: Ryu Euiyoul <[email protected]> |
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** - added power management suspend and resume code |
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* |
046 |
* 2011-6-23: ADS7846触摸屏驱动程序 by liu_xf |
048 |
* |
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* 2011-6-29 改进滤波,并将AD连续转换8次的间隔缩小了 |
050 |
*/ |
051 |
|
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#include <linux/errno.h> |
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#include <linux/kernel.h> |
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#include <linux/module.h> |
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#include <linux/slab.h> |
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#include <linux/input.h> |
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#include <linux/init.h> |
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#include <linux/serio.h> |
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#include <linux/delay.h> |
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#include <linux/platform_device.h> |
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#include <linux/clk.h> |
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#include <linux/fs.h> |
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#include <linux/poll.h> |
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#include <linux/irq.h> |
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#include <linux/interrupt.h> |
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#include <linux/cdev.h> |
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#include <linux/miscdevice.h> |
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|
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#include <asm/uaccess.h> |
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#include <asm/io.h> |
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#include <asm/irq.h> |
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#include <mach/hardware.h> |
073 |
|
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|
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//#include <mach/irqs.h> |
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#include <mach/map.h> |
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#include <mach/regs-clock.h> |
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#include <mach/regs-gpio.h> |
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#include <plat/gpio-cfg.h> |
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#include <mach/gpio-bank-n.h> |
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#include <mach/gpio-bank-c.h> |
082 |
|
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|
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#define CONFIG_TOUCHSCREEN_ADS7846_DEBUG |
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#undef CONFIG_TOUCHSCREEN_ADS7846_DEBUG |
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#define DEBUG_LVL KERN_DEBUG |
087 |
|
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|
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/* |
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* Definitions & global arrays. |
091 |
*/ |
092 |
#define DEVICE_NAME "touchscreen" |
093 |
static DECLARE_WAIT_QUEUE_HEAD(ts_waitq); //定义并初始化一个等待队列 |
094 |
|
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typedef unsigned TS_EVENT; |
096 |
#define NR_EVENTS 64 //触摸屏fifo大小 |
097 |
|
098 |
|
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static TS_EVENT events[NR_EVENTS]; |
100 |
static int evt_head, evt_tail; //fifo的头的尾 |
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//驱动写fifo时evt_head++,应用读fifo时 evt_tail++ |
102 |
|
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#define ts_evt_pending() ((volatile u8)(evt_head != evt_tail)) //相等就表示满了 |
104 |
#define ts_evt_get() (events + evt_tail) |
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#define ts_evt_pull() (evt_tail = (evt_tail + 1) & (NR_EVENTS - 1)) |
106 |
#define ts_evt_clear() (evt_head = evt_tail = 0) |
107 |
|
108 |
#define ADS7846_CNV_NBR 8 //ADC连续转换的次数 |
109 |
struct ads7846_ts_info { |
110 |
|
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struct input_dev *dev; |
112 |
|
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unsigned int xp; //x方向位置 |
114 |
unsigned int yp; //y方向位置 |
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unsigned int count; //adc转换次数 |
116 |
unsigned int cnv_nbr; |
117 |
unsigned int x_buf[ADS7846_CNV_NBR]; //ad转换buf |
118 |
unsigned int y_buf[ADS7846_CNV_NBR]; |
119 |
|
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}; |
121 |
|
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static struct ads7846_ts_info *ts; |
123 |
|
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|
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|
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|
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//ADS7846底层操作======================================================================== |
128 |
#define ADS7846_GPIO_MISO 0 //gpc0 |
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#define ADS7846_GPIO_MOSI 2 //gpc2 |
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#define ADS7846_GPIO_CLK 1 //gpc1 |
131 |
#define ADS7846_GPIO_CS 3 //gpc3 |
132 |
|
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// ADS7846 Control Byte bit defines |
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#define ADS7846_CMD_START 0x0080 |
135 |
#define ADS7846_ADDR_BIT 4 |
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#define ADS7846_ADDR_MASK (0x7<<ADS7846_ADDR_BIT) |
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#define ADS7846_MEASURE_X (0x5<<ADS7846_ADDR_BIT) |
138 |
#define ADS7846_MEASURE_Y (0x1<<ADS7846_ADDR_BIT) |
139 |
#define ADS7846_MEASURE_Z1 (0x3<<ADS7846_ADDR_BIT) |
140 |
#define ADS7846_MEASURE_Z2 (0x4<<ADS7846_ADDR_BIT) |
141 |
#define ADS7846_8BITS (1<<3) |
142 |
#define ADS7846_12BITS 0 |
143 |
#define ADS7846_SER (1<<2) |
144 |
#define ADS7846_DFR 0 |
145 |
#define ADS7846_PWR_BIT 0 |
146 |
#define ADS7846_PD 0 |
147 |
#define ADS7846_ADC_ON (0x1<<ADS7846_PWR_BIT) |
148 |
#define ADS7846_REF_ON (0x2<<ADS7846_PWR_BIT) |
149 |
#define ADS7846_REF_ADC_ON (0x3<<ADS7846_PWR_BIT) |
150 |
|
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#define MEASURE_8BIT_X\ |
152 |
(unsigned short )(ADS7846_CMD_START | ADS7846_MEASURE_X | ADS7846_8BITS | ADS7846_DFR | ADS7846_PD) |
153 |
#define MEASURE_8BIT_Y\ |
154 |
(unsigned short )(ADS7846_CMD_START | ADS7846_MEASURE_Y | ADS7846_8BITS | ADS7846_DFR | ADS7846_PD) |
155 |
|
156 |
#define MEASURE_12BIT_X \ |
157 |
(unsigned short )(ADS7846_CMD_START | ADS7846_MEASURE_X | ADS7846_12BITS | ADS7846_DFR | ADS7846_PD) |
158 |
#define MEASURE_12BIT_Y \ |
159 |
(unsigned short )(ADS7846_CMD_START | ADS7846_MEASURE_Y | ADS7846_12BITS | ADS7846_DFR | ADS7846_PD) |
160 |
#define MEASURE_12BIT_Z1 \ |
161 |
(unsigned char )(ADS7846_MEASURE_Z1 | ADS7846_12BITS | ADS7846_DFR | ADS7846_PD) |
162 |
#define MEASURE_12BIT_Z2 \ |
163 |
(unsigned char )(ADS7846_MEASURE_Z2 | ADS7846_12BITS | ADS7846_DFR | ADS7846_PD) |
164 |
|
165 |
// Pin access |
166 |
// |
167 |
static inline void set_miso_as_up( void ) //gpc0 |
168 |
{ |
169 |
unsigned long tmp; |
170 |
tmp = readl(S3C64XX_GPCPUD); |
171 |
tmp &= ~(3U <<0); |
172 |
tmp |= (2U << 0); |
173 |
writel(tmp, S3C64XX_GPCPUD); |
174 |
} |
175 |
|
176 |
static inline void set_miso_as_input( void ) //gpc0 |
177 |
{ |
178 |
unsigned long tmp; |
179 |
tmp = readl(S3C64XX_GPCCON); |
180 |
tmp &= ~(0xf << 0); |
181 |
writel(tmp, S3C64XX_GPCCON); |
182 |
} |
183 |
|
184 |
static inline void set_cs_mosi_clk_as_output( void ) //gpc1 2 3 |
185 |
{ |
186 |
unsigned long tmp; |
187 |
tmp = readl(S3C64XX_GPCCON); |
188 |
tmp = (tmp & ~0xfff0) | (0x1110); |
189 |
writel(tmp, S3C64XX_GPCCON); |
190 |
} |
191 |
|
192 |
static inline void set_cs_mosi_clk_as_up( void ) //gpc1 2 3 |
193 |
{ |
194 |
unsigned long tmp; |
195 |
tmp = readl(S3C64XX_GPCPUD); |
196 |
tmp &= ~((3U <<2)|(3U <<4)|(3U <<6)); |
197 |
tmp |= (2U << 2) | (2U << 4) | (2U << 6); |
198 |
writel(tmp, S3C64XX_GPCPUD); |
199 |
} |
200 |
|
201 |
|
202 |
static inline void set_gpcx_value( int pinx , int v) |
203 |
{ |
204 |
unsigned long tmp; |
205 |
tmp = readl(S3C64XX_GPCDAT); |
206 |
if (v) { |
207 |
tmp |= (1 << pinx); |
208 |
} else { |
209 |
tmp &= ~(1<<pinx); |
210 |
} |
211 |
writel(tmp, S3C64XX_GPCDAT); |
212 |
} |
213 |
|
214 |
static inline int get_gpcx_value( int pinx) |
215 |
{ |
216 |
int v; |
217 |
unsigned long tmp; |
218 |
tmp = readl(S3C64XX_GPCDAT); |
219 |
v = !!(tmp & (1<<pinx)); |
220 |
return v; |
221 |
} |
222 |
|
223 |
//读12bit |
224 |
static unsigned int ads7846_Read_Data( void ) |
225 |
{ |
226 |
unsigned int i,temp=0x00; |
227 |
for (i=0;i<12;i++) |
228 |
{ |
229 |
temp <<=1; |
230 |
set_gpcx_value(ADS7846_GPIO_CLK, 1); udelay(10); |
231 |
set_gpcx_value(ADS7846_GPIO_CLK, 0); udelay(10); |
232 |
if (get_gpcx_value(ADS7846_GPIO_MISO) != 0)temp++; |
233 |
} |
234 |
return (temp); |
235 |
} |
236 |
//写8bit |
237 |
static void ads7846_Write_Data(unsigned int n) |
238 |
{ |
239 |
unsigned char i; |
240 |
set_gpcx_value(ADS7846_GPIO_CLK, 0); |
241 |
for (i=0;i<8;i++) |
242 |
{ |
243 |
if ((n&0x80)==0x80) |
244 |
set_gpcx_value(ADS7846_GPIO_MOSI, 1); |
245 |
else |
246 |
set_gpcx_value(ADS7846_GPIO_MOSI, 0); |
247 |
|
248 |
n <<= 1; |
249 |
set_gpcx_value(ADS7846_GPIO_CLK, 1); udelay(10); |
250 |
set_gpcx_value(ADS7846_GPIO_CLK, 0); udelay(10); |
251 |
} |
252 |
} |
253 |
|
254 |
|
255 |
//ADS7846转换== |
256 |
//保存在ts->buf 当中 |
257 |
static void ads7846_conver_start( void ) |
258 |
{ |
259 |
int i; |
260 |
unsigned int cmd[2]; |
261 |
unsigned int data[2]; |
262 |
|
263 |
set_gpcx_value(ADS7846_GPIO_CS, 0); |
264 |
//开读 |
265 |
cmd[0] = MEASURE_12BIT_X; |
266 |
cmd[1] = MEASURE_12BIT_Y; |
267 |
|
268 |
/* CS# Low */ |
269 |
set_gpcx_value(ADS7846_GPIO_CS, 0); |
270 |
|
271 |
//连续转换 |
272 |
for (ts->count=0; ts->count<ts->cnv_nbr;) |
273 |
{ |
274 |
//分别读出x y坐标== |
275 |
for (i=0; i<2; i++){ |
276 |
ads7846_Write_Data(cmd[i]); |
277 |
udelay(40); |
278 |
data[i] = ads7846_Read_Data(); |
279 |
} |
280 |
|
281 |
|
282 |
|
283 |
//保存转换结果 |
284 |
ts->x_buf[ts->count]= data[0]; |
285 |
ts->y_buf[ts->count]= data[1]; |
286 |
ts->count++; |
287 |
} |
288 |
/* CS# High */ |
289 |
set_gpcx_value(ADS7846_GPIO_CS, 1); |
290 |
|
291 |
#ifdef CONFIG_TOUCHSCREEN_ADS7846_DEBUG |
292 |
//printk("ts read pos: x = %d, y = %d\n", data[0], data[1]); |
293 |
#endif |
294 |
|
295 |
} |
296 |
|
297 |
|
298 |
//----------------------------------------------------------------------------- |
299 |
|
300 |
//触摸屏数据滤波算法 |
301 |
//触摸屏AD连续转换N次后,按升序排列,再取中间几位值求平均 |
302 |
#define TS_AD_NBR_PJ 4 //取中间4位求平均值 |
303 |
#define TS_AD_NBR_MAX_CZ 10 //最大与最小的差值 |
304 |
static inline bool touch_ad_data_filter(unsigned int *buf0, unsigned int *buf1) |
305 |
{ |
306 |
unsigned int i,j,k,temp,temp1,nbr=(ADS7846_CNV_NBR); |
307 |
//将转换结果升序排列 |
308 |
//buf0 |
309 |
for (j= 0; j< nbr; j++) |
310 |
for (i = 0; i < nbr; i++) |
311 |
{ |
312 |
if (buf0[i]>buf0[i+1]) //升序排列 |
313 |
{ |
314 |
temp=buf0[i+1]; |
315 |
buf0[i+1]=buf0[i]; |
316 |
buf0[i]=temp; |
317 |
} |
318 |
} |
319 |
|
320 |
//buf1 |
321 |
for (j= 0; j< nbr; j++) |
322 |
for (i = 0; i < nbr; i++) |
323 |
{ |
324 |
if (buf1[i]>buf1[i+1]) //升序排列 |
325 |
{ |
326 |
temp=buf1[i+1]; |
327 |
buf1[i+1]=buf1[i]; |
328 |
buf1[i]=temp; |
329 |
} |
330 |
} |
331 |
|
332 |
//串口调试查看结果 |
333 |
//for (j= 0; j< nbr; j++) |
334 |
// printk("buf0[%2d]=%4d, buf1[%2d]=%4d,\r\n",j,buf0[j],j,buf1[j]); |
335 |
//取中间值求平均== |
336 |
k=((nbr-TS_AD_NBR_PJ)>>1); |
337 |
temp = 0;temp1 = 0; |
338 |
//检查值是否有效== |
339 |
if ((buf0[k+TS_AD_NBR_PJ-1]-buf0[k]>TS_AD_NBR_MAX_CZ)||(buf1[k+TS_AD_NBR_PJ-1]-buf1[k]>TS_AD_NBR_MAX_CZ)) //无效值 |
340 |
{ |
341 |
|
342 |
return 0; |
343 |
} |
344 |
//-- |
345 |
//将中间指定位数累加 |
346 |
for (i=0;i<TS_AD_NBR_PJ;i++) |
347 |
{ |
348 |
temp += buf0[k+i]; |
349 |
temp1 += buf1[k+i]; |
350 |
} |
351 |
//求平均值,将结果保存在最低位 |
352 |
buf0[0]=temp/TS_AD_NBR_PJ; |
353 |
buf1[0] = temp1/TS_AD_NBR_PJ; |
354 |
//-- |
355 |
return 1; |
356 |
|
357 |
} |
358 |
|
359 |
|
360 |
//将AD转换的值放入FIFO |
361 |
//这里是一个先进先出的fifo |
362 |
//只要有数据被添加进来,就会唤醒ts_waitq进程 |
363 |
static void ts_evt_add(unsigned x, unsigned y, unsigned down) { |
364 |
unsigned ts_event; |
365 |
int next_head; |
366 |
|
367 |
ts_event = ((x << 16) | (y)) | (down << 31); |
368 |
next_head = (evt_head + 1) & (NR_EVENTS - 1); |
369 |
//没满就装入 |
370 |
if (next_head != evt_tail) { |
371 |
events[evt_head] = ts_event; |
372 |
evt_head = next_head; |
373 |
#ifdef CONFIG_TOUCHSCREEN_ADS7846_DEBUG |
374 |
printk( "====>Add ... [ %4d, %4d ]%s\n" , x, y, down ? "" : " ~~~" ); |
375 |
#endif |
376 |
/* wake up any read call */ |
377 |
if (waitqueue_active(&ts_waitq)) { //判斷等待隊列是否有進程睡眠 |
378 |
wake_up_interruptible(&ts_waitq); //唤醒ts_waitq等待队列中所有interruptible类型的进程 |
379 |
} |
380 |
} else { |
381 |
/* drop the event and try to wakeup readers */ |
382 |
printk(KERN_WARNING "mini6410-ads7846: touch event buffer full" ); |
383 |
wake_up_interruptible(&ts_waitq); |
384 |
} |
385 |
} |
386 |
|
387 |
static unsigned int ads7846_ts_poll( struct file *file, struct poll_table_struct *wait) |
388 |
{ |
389 |
unsigned int mask = 0; |
390 |
|
391 |
//将ts_waitq等待队列添加到poll_table里去 |
392 |
poll_wait(file, &ts_waitq, wait); |
393 |
//返回掩码 |
394 |
if (ts_evt_pending()) |
395 |
mask |= POLLIN | POLLRDNORM; //返回设备可读 |
396 |
|
397 |
return mask; |
398 |
} |
399 |
|
400 |
//读 系统调用== |
401 |
static int ads7846_ts_read( struct file *filp, char __user *buff, size_t count, loff_t *offp) |
402 |
{ |
403 |
DECLARE_WAITQUEUE(wait, current); //把当前进程加到定义的等待队列头wait中 |
404 |
char *ptr = buff; |
405 |
int err = 0; |
406 |
|
407 |
add_wait_queue(&ts_waitq, &wait); //把wait入到等待队列头中。该队列会在进程等待的条件满足时唤醒它。 |
408 |
//我们必须在其他地方写相关代码,在事件发生时,对等的队列执行wake_up()操作。 |
409 |
//这里是在ts_evt_add里wake_up |
410 |
while (count >= sizeof (TS_EVENT)) { |
411 |
err = -ERESTARTSYS; |
412 |
if (signal_pending(current)) //如果是信号唤醒 参考http://www.360doc.com/content/10/1009/17/1317564_59632874.shtml |
413 |
break ; |
414 |
|
415 |
if (ts_evt_pending()) { |
416 |
TS_EVENT *evt = ts_evt_get(); |
417 |
|
418 |
err = copy_to_user(ptr, evt, sizeof (TS_EVENT)); |
419 |
ts_evt_pull(); |
420 |
|
421 |
if (err) |
422 |
break ; |
423 |
|
424 |
ptr += sizeof (TS_EVENT); |
425 |
count -= sizeof (TS_EVENT); |
426 |
continue ; |
427 |
} |
428 |
|
429 |
set_current_state(TASK_INTERRUPTIBLE); //改变进程状态为可中断的睡眠 |
430 |
err = -EAGAIN; |
431 |
if (filp->f_flags & O_NONBLOCK) //如果上层调用是非阻塞方式,则不阻塞该进程,直接返回EAGAIN |
432 |
break ; |
433 |
schedule(); //本进程在此处交出CPU控制权,等待被唤醒 |
434 |
//进程调度的意思侧重于把当前任务从CPU拿掉,再从就绪队列中按照调度算法取一就绪进程占用CPU |
435 |
} |
436 |
current->state = TASK_RUNNING; |
437 |
remove_wait_queue(&ts_waitq, &wait); |
438 |
|
439 |
return ptr == buff ? err : ptr - buff; |
440 |
} |
441 |
//-- |
442 |
|
443 |
static int ads7846_ts_open( struct inode *inode, struct file *filp) { |
444 |
/* flush event queue */ |
445 |
ts_evt_clear(); |
446 |
|
447 |
return 0; |
448 |
} |
449 |
|
450 |
//当应用程序操作设备文件时调用的open read等函数,最终会调用这个结构体中对应的函数 |
451 |
static struct file_operations dev_fops = { |
452 |
.owner = THIS_MODULE, |
453 |
.read = ads7846_ts_read, |
454 |
.poll = ads7846_ts_poll, //select系统调用 |
455 |
.open = ads7846_ts_open, |
456 |
}; |
457 |
|
458 |
//设备号,设备名,注册的时候用到这个数组 |
459 |
//混杂设备主设备号为10 |
460 |
static struct miscdevice misc = { |
461 |
.minor = MISC_DYNAMIC_MINOR, //自动分配次设置号 |
462 |
//.minor = 180, |
463 |
.name = DEVICE_NAME, |
464 |
.fops = &dev_fops, |
465 |
}; |
466 |
|
467 |
|
468 |
|
469 |
|
470 |
|
471 |
|
472 |
/** |
473 |
* get_down - return the down state of the pen |
474 |
* 获取pen引脚状态,为0表示down |
475 |
* GPN9 EINT9 TS_PEN |
476 |
*/ |
477 |
static inline bool get_down( void ) |
478 |
{ |
479 |
int tmp,down; |
480 |
tmp = readl(S3C64XX_GPNDAT); |
481 |
down = !(tmp & (1<<9)); |
482 |
return (down); |
483 |
} |
484 |
|
485 |
|
486 |
/*=========================================================================================== |
487 |
touch_timer_get_value这个函数的调用: |
488 |
|
489 |
1、 触摸笔开始点击的时候, 在中断函数touch_down里面被调用,不是直接调用,而是设置定时器超时后调用 |
490 |
这样是为了去抖动 |
491 |
|
492 |
2、 touch_timer_get_value被调用一次后,如果pendown信号有效,则touch_timer_get_value会被持续调用 |
493 |
也是通过定时器实现的 |
494 |
|
495 |
touch_timer_get_value这个函数的功能: |
496 |
启动7846转换,直到连续转换8次后,再滤波处理,获得有效值,并向上报告触摸屏事件 |
497 |
|
498 |
============================================================================================*/ |
499 |
static void touch_timer_get_value(unsigned long data); |
500 |
|
501 |
static DEFINE_TIMER(touch_timer, touch_timer_get_value, 0, 0); |
502 |
|
503 |
static void touch_timer_get_value(unsigned long data) { |
504 |
|
505 |
int pendown; |
506 |
|
507 |
pendown = get_down(); |
508 |
|
509 |
#ifdef CONFIG_TOUCHSCREEN_ADS7846_DEBUG |
510 |
// if(pendown) |
511 |
// { |
512 |
// printk("touch is down!\n"); |
513 |
// } |
514 |
// else |
515 |
// printk("touch is up!\n"); |
516 |
#endif |
517 |
|
518 |
if (pendown) { |
519 |
|
520 |
//关中断=== |
521 |
disable_irq(IRQ_EINT(9)); |
522 |
//-- |
523 |
//启动ADS7846转换== |
524 |
ads7846_conver_start(); |
525 |
//开中断== |
526 |
enable_irq(IRQ_EINT(9)); |
527 |
//-- |
528 |
//如果转换了8次,就写入FIFO保存 |
529 |
//if (ts->count == ( ts->cnv_nbr)) { |
530 |
if (touch_ad_data_filter(ts->x_buf,ts->y_buf)) //滤波处理 |
531 |
{ |
532 |
|
533 |
ts->xp = ts->x_buf[0]; |
534 |
ts->yp = ts->y_buf[0]; |
535 |
|
536 |
ts_evt_add(ts->xp, ts->yp, 1); //向上报告触摸屏事件 |
537 |
} |
538 |
|
539 |
|
540 |
ts->xp = 0; |
541 |
ts->yp = 0; |
542 |
ts->count = 0; |
543 |
//} |
544 |
//-- |
545 |
|
546 |
mod_timer(&touch_timer, jiffies + 2); //重新设置系统定时器,超时后,又会调用touch_timer_get_value |
547 |
//jiffies变量记录了系统启动以来,系统定时器已经触发的次数。内核每秒钟将jiffies变量增加HZ次。 |
548 |
//因此,对于HZ值为100的系统,1个jiffy等于10ms,而对于HZ为1000的系统,1个jiffy仅为1ms |
549 |
//这里系统配置提HZ是100 |
550 |
|
551 |
} else { //如果是松开,报告其触摸笔状态 |
552 |
ts->xp = 0; |
553 |
ts->yp = 0; |
554 |
ts->count = 0; |
555 |
|
556 |
ts_evt_add(0, 0, 0); |
557 |
|
558 |
|
559 |
} |
560 |
|
561 |
} |
562 |
|
563 |
|
564 |
|
565 |
//触摸屏按下中断服务== |
566 |
//双边沿中断 |
567 |
static irqreturn_t touch_down( int irqno, void *param) |
568 |
{ |
569 |
|
570 |
|
571 |
/* Clear interrupt */ |
572 |
//__raw_writel(0x0, ts_base + S3C_ADCCLRWK); |
573 |
//__raw_writel(0x0, ts_base + S3C_ADCCLRINT); |
574 |
|
575 |
//稍后调用touch_timer_get_value,去抖动 |
576 |
mod_timer(&touch_timer, jiffies + 2); //等ADS7846转换完成了再读 |
577 |
//同时还可以防抖动,如果定时器没有超时的这段时间里,发生了抬起和按下中断,则定时器的值会被重设,不会超时 |
578 |
//内核配置时HZ值设为100,即1个jiffy等于10ms, |
579 |
//touch_timer_get_value(1); //直接调用会有抖动 |
580 |
|
581 |
return IRQ_RETVAL(IRQ_HANDLED); |
582 |
} |
583 |
|
584 |
|
585 |
|
586 |
|
587 |
//------------------------------------------- |
588 |
|
589 |
|
590 |
/* |
591 |
* The functions for inserting/removing us as a module. |
592 |
*/ |
593 |
static int __init ads7846_ts_probe( struct platform_device *pdev) |
594 |
{ |
595 |
struct device *dev; |
596 |
int ret = 0; |
597 |
|
598 |
dev = &pdev->dev; |
599 |
#ifdef CONFIG_TOUCHSCREEN_ADS7846_DEBUG |
600 |
printk( "ads7846_ts_probe start!\n" ); |
601 |
#endif |
602 |
//给ads7846_ts_info指针分配内存== |
603 |
ts = kzalloc( sizeof ( struct ads7846_ts_info), GFP_KERNEL); |
604 |
ts->cnv_nbr = ADS7846_CNV_NBR; |
605 |
ts->xp = 0; |
606 |
ts->yp = 0; |
607 |
ts->count = 0; |
608 |
|
609 |
|
610 |
//申请中断== |
611 |
//TS_PEN双边沿触发 EINT9 GPN9 |
612 |
ret = request_irq(IRQ_EINT(9), touch_down,IRQ_TYPE_EDGE_BOTH, |
613 |
"ads7864_touch" , ts); |
614 |
|
615 |
if (ret != 0) { |
616 |
dev_err(dev, "ads7846_ts.c: Could not allocate ts IRQ_EINT !\n" ); |
617 |
ret = -EIO; |
618 |
goto fail; |
619 |
} |
620 |
|
621 |
|
622 |
|
623 |
|
624 |
ret = misc_register(&misc); //注册这混杂字符设备 |
625 |
if (ret) { |
626 |
dev_err(dev, "ads7846_ts.c: Could not register device(mini6410 touchscreen)!\n" ); |
627 |
ret = -EIO; |
628 |
goto fail; |
629 |
} |
630 |
//初始化GPIO== |
631 |
set_miso_as_up(); |
632 |
set_miso_as_input(); |
633 |
set_cs_mosi_clk_as_up(); |
634 |
set_cs_mosi_clk_as_output(); |
635 |
set_gpcx_value(ADS7846_GPIO_MOSI ,1); |
636 |
set_gpcx_value(ADS7846_GPIO_CS ,1); |
637 |
set_gpcx_value(ADS7846_GPIO_CLK ,1); |
638 |
//-- |
639 |
|
640 |
#ifdef CONFIG_TOUCHSCREEN_ADS7846_DEBUG |
641 |
printk( "ads7846_ts_probe end!\n" ); |
642 |
#endif |
643 |
|
644 |
return 0; |
645 |
|
646 |
fail: |
647 |
disable_irq(IRQ_EINT(9)); |
648 |
free_irq(IRQ_EINT(9), ts); |
649 |
|
650 |
return ret; |
651 |
|
652 |
} |
653 |
|
654 |
static int ads7846_ts_remove( struct platform_device *dev) |
655 |
{ |
656 |
printk(KERN_INFO "ads7846_ts_remove() of TS called !\n" ); |
657 |
|
658 |
disable_irq(IRQ_EINT(9)); |
659 |
free_irq(IRQ_EINT(9), ts); |
660 |
return 0; |
661 |
} |
662 |
|
663 |
#ifdef CONFIG_PM |
664 |
static unsigned int adccon, adctsc, adcdly; |
665 |
|
666 |
static int ads7846_ts_suspend( struct platform_device *dev, pm_message_t state) |
667 |
{ |
668 |
|
669 |
return 0; |
670 |
} |
671 |
|
672 |
static int ads7846_ts_resume( struct platform_device *pdev) |
673 |
{ |
674 |
return 0; |
675 |
} |
676 |
#else |
677 |
#define ads7846_ts_suspend NULL |
678 |
#define ads7846_ts_resume NULL |
679 |
#endif |
680 |
|
681 |
static struct platform_driver ads7846_ts_driver = { |
682 |
.probe = ads7846_ts_probe, |
683 |
. remove = ads7846_ts_remove, |
684 |
.suspend = ads7846_ts_suspend, |
685 |
.resume = ads7846_ts_resume, |
686 |
.driver = { |
687 |
.owner = THIS_MODULE, |
688 |
.name = "ads7846-ts" , |
689 |
}, |
690 |
}; |
691 |
|
692 |
static char banner[] __initdata = KERN_INFO "mini6410 ads7846 Touchscreen driver,by liu_xf 20110622,\n" ; |
693 |
|
694 |
static int __init ads7846_ts_init( void ) |
695 |
{ |
696 |
printk(banner); |
697 |
return platform_driver_register(&ads7846_ts_driver); |
698 |
} |
699 |
|
700 |
static void __exit ads7846_ts_exit( void ) |
701 |
{ |
702 |
platform_driver_unregister(&ads7846_ts_driver); |
703 |
} |
704 |
|
705 |
module_init(ads7846_ts_init); |
706 |
module_exit(ads7846_ts_exit); |
707 |
|
708 |
MODULE_AUTHOR( "Hunan Create Inc." ); |
709 |
MODULE_LICENSE( "GPL" ); |
2、修改当前目录下的Kconfig和makefile,让它在menuconfig里可见,并能被编译。
在 Kconfig里添加:
01 |
config TOUCHSCREEN_MINI6410_ADS7846 |
02 |
tristate "ADS7846 touchscreen driver for Mini6410" |
03 |
depends on MACH_MINI6410 |
04 |
default y |
05 |
help |
06 |
Say Y here to enable the driver for the ADS7846 touchscreen on the |
07 |
FriendlyARM Mini6410 development board. |
08 |
|
09 |
If unsure, say N. |
10 |
|
11 |
To compile this driver as a module, choose M here: the |
12 |
module will be called mini6410-ads7846. |
makefile里添加
obj-$(CONFIG_TOUCHSCREEN_MINI6410_ADS7846) += mini6410-ads7846.o<BR> |
3、 ads7846_device_ts设备定义
复制 /opt/FriendlyARM/mini6410/linux-2.6.38/arch/arm/mach-s3c64xx/dev-ts-mini6410.c为dev-ads7846-mini6410.c,更改代码为
01 |
/* linux/arch/arm/mach-s3c64xx/dev-ts-mini6410.c |
02 |
* |
03 |
* Copyright (c) 2008 Simtec Electronics |
04 |
* Ben Dooks <[email protected]> |
06 |
* |
07 |
* S3C series device definition for touchscreen devices |
08 |
* |
09 |
* This program is free software; you can redistribute it and/or modify |
10 |
* it under the terms of the GNU General Public License version 2 as |
11 |
* published by the Free Software Foundation. |
12 |
*/ |
13 |
|
14 |
#include <linux/kernel.h> |
15 |
#include <linux/platform_device.h> |
16 |
|
17 |
#include <mach/map.h> |
18 |
#include <mach/irqs.h> |
19 |
#include <plat/devs.h> |
20 |
#include <plat/cpu.h> |
21 |
#include <mach/ts.h> |
22 |
|
23 |
/* Touch srcreen */ |
24 |
//resource没有用,先留在这,不管它 |
25 |
static struct resource ads7846_ts_resource[] = { |
26 |
[0] = { |
27 |
.start = SAMSUNG_PA_ADC, |
28 |
.end = SAMSUNG_PA_ADC + SZ_256 - 1, |
29 |
.flags = IORESOURCE_MEM, |
30 |
}, |
31 |
[1] = { |
32 |
.start = IRQ_PENDN, |
33 |
.end = IRQ_PENDN, |
34 |
.flags = IORESOURCE_IRQ, |
35 |
}, |
36 |
[2] = { |
37 |
.start = IRQ_ADC, |
38 |
.end = IRQ_ADC, |
39 |
.flags = IORESOURCE_IRQ, |
40 |
} |
41 |
}; |
42 |
|
43 |
struct platform_device ads7846_device_ts = { |
44 |
.name = "ads7846-ts" , |
45 |
.id = -1, |
46 |
.num_resources = ARRAY_SIZE(ads7846_ts_resource), |
47 |
.resource = ads7846_ts_resource, |
48 |
}; |
49 |
/* |
50 |
void __init ads7846_ts_set_platdata(struct s3c_ts_mach_info *pd) |
51 |
{ |
52 |
printk(KERN_ERR "%s: no platform data\n", __func__); |
53 |
|
54 |
} |
55 |
*/ |
4、在/opt/FriendlyARM/mini6410/linux-2.6.38/arch/arm/mach-s3c64xx/mach-mini6410.c的platform_device添加ads7846_device_ts设备(s3c_device_ts附近),注册设备时要用到它
#ifdef CONFIG_TOUCHSCREEN_MINI6410_ADS7846 |
&ads7846_device_ts, |
#endif |
5、添加设备声明
mach-mini6410里注册ads7846_device_ts设备,但在哪里mach-mini6410并不知道,需要在devs.h里声明,打开当前目录下的devs.h,添加如下代码:
extern struct platform_device ads7846_device_ts;<BR> |
6、然后再make,放到SD卡里运行
make menuconfig,在device drives-> input device support -> touch screens选择ADS7846 touchscreen driver for Mini6410 ,然后再make zImage。
完成后,再放到SD卡里运行,怎么样,一点也不抖动了吧!
结语:
这个驱动是由mini6410-ts.c修改而来的,那些系统调用的函数都没有改,只是将获取触摸屏数据的方式变了,可以直接用原来的tslib。经测试,效果良好。但是在移植的过程中,有一个问题还是没搞明白,之前,我是将TS_PEN接在EINT6上在的,但一接上去,就一直中断,把系统都弄死了,要按下触摸屏才能停止中断,不知道是什么原因,可能是EINT6被其它地方设置了,还是怎么回事,后来换成EINT9就好了,正好两个端子相邻。知道的大侠还请告诉我一声。