GPIO模拟SPI通讯接口的驱动

1、GPIO模拟SPI通讯接口的驱动，某些时候我们会不得不使用GPIO来模拟SPI,I2C等通讯接口，如本例中，需要使用SPI接口发送9位的数据，如果使用linux内核提供的SPI子系统来做这个驱动是无法实现9位传输数据的。二，用GPIO模拟SPI总的来说是比较简单，把相应的管脚配置成GPIO功能，再按需要配置管脚的输入输出方向，然后根据SPI总线的时序设定IO口的电平。三，驱动代码如下，以备今后作参考：(linux-2.6.28+TCC8900,这个驱动是用来控制LCD的初始化的(型号为LW350AC9001)#include<linux/module.h>#include<l

2、inux/types.h>#include<linux/kernel.h>#include<linux/init.h>#include<linux/ioport.h>#include<asm/uaccess.h>#include<linux/delay.h>#include<bsp.h>#include<asm/io.h>#definePDEBUG#ifdefPDEBUG#definePLOG(fmt,args.)printk(fmt,#args)#else#definePLOG(fmt,args.)/*

3、donothing*/#endif#defineSPI_CMD0#defineSPI_DATA1#defineFUN_GPIO0#definePIN_SDO15GPIOF15#definePIN_SDI14#definePIN_SCLK16#definePIN_CS29GPIOC29#defineGPC_BASE0xF0102080#defineGPF_BASE0xF0102140#defineOFFSET_DAT0x0#defineOFFSET_EN0x4#defineOFFSET_FUN00x24#defineOFFSET_FUN10x28#defineOFFSET_FUN20x2c#de

4、fineOFFSET_FUN30x30/selectpinusedforgpiostaticinttcc_set_pin_fun(intpin,intfun)if(pin<8)tcc_writel(tcc_readl(GPF_BASE+OFFSET_FUNO)&(0x0f<<(4*pin)|(fun<<(4*pin),GPF_BASE+OFFSET_FUNO);elseif(pi*16)tcc_writel(tcc_readl(GPF_BASE+OFFSET_FUN1)&(0x0f<<(4*(pin-8)|(fun<<(4*

5、(pin-8),GPF_BASE+OFFSET_FUN1);elseif(pi*24)tcc_writel(tcc_readl(GPF_BASE+OFFSET_FUN2)&(0x0f<<(4*(pin-16)|(fun<<(4*(pin-16),GPF_BASE+OFFSET_FUN2);elseif(pin<32)tcc_writel(tcc_readl(GPF_BASE+0FFSET_FUN3)&(0x0f<<(4*(pin-24)|(fun<<(4*(pin-24),GPF_BASE+OFFSET_FUN3);retu

6、rn0;staticinttcc_set_cs_fun(void)tcc_writel(tcc_readl(GPC_BASE+OFFSET_FUN3)&(0x0f<<(4*(PIN_CS-24),GPC_BASE+OFFSET_FUN3);return0;/setgpiodirection,output:1foroutput,0forinputstaticinttcc_set_gpio_direction(intpin,intoutput)tcc_writel(tcc_readl(GPF_BASE+OFFSET_EN)&(1<<pin)|(output&

7、lt;<pin),GPF_BASE+OFFSET_EN);return0;staticinttcc_set_cs_output(void)tcc_writel(tcc_readl(GPC_BASE+OFFSET_EN)|(1<<PIN_CS),GPC_BASE+OFFSET_EN);return0;/setgpiopinlevel,high:1,low:0staticinttcc_set_gpio_data(intpin,intlevel)tcc_writel(tcc_readl(GPF_BASE+OFFSET_DAT)&(1<<pin)|(level&l

8、t;<pin),GPF_BASE+OFFSET_DAT);return0;staticinttcc_set_cs_data(intlevel)tcc_writel(tcc_readl(GPC_BASE+OFFSET_DAT)&(1<<PIN_CS)|(level<<PIN_CS),GPC_BASE+OFFSET_DAT);return0;/getgpiopinlevel,high:1,low:0staticinttcc_get_gpio_data(intpin)return(tcc_readl(GPF_BASE+OFFSET_DAT)>>pin

9、)&1);voidSPI_init(void)tcc_set_pin_fun(PIN_SDO,FUN_GPIO);/configurepinsdoandsdaasGPIOtcc_set_pin_fun(PIN_SDI,FUN_GPIO);tcc_set_pin_fun(PIN_SCLK,FUN_GPIO);tcc_set_gpio_direction(PIN_SDO,1);tcc_set_gpio_direction(PIN_SDI,1);tcc_set_gpio_direction(PIN_SCLK,1);tcc_set_gpio_data(PIN_SDO,1);tcc_set_gp

10、io_data(PIN_SDI,1);tcc_set_gpio_data(PIN_SCLK,1);tcc_set_cs_fun();tcc_set_cs_output();tcc_set_cs_data(1);voidSPI_send(boolis_parameter,unsignedcharw_data)unsignedcharvsignbit;/sendDNC-bittcc_set_gpio_data(PIN_SCLK,0);tcc_set_gpio_data(PIN_SDO,is_parameter);ndelay(20);tcc_set_gpio_data(PIN_SCLK,1);nd

11、elay(20);for(vsignbit=0x80;vsignbit>O;vsignbit>>=1)tcc_set_gpio_data(PIN_SCLK,0);if(w_data&vsignbit)tcc_set_gpio_data(PIN_SDO,1);elsetcc_set_gpio_data(PIN_SDO,0);ndelay(20);tcc_set_gpio_data(PIN_SCLK,1);ndelay(20);tcc_set_gpio_data(PIN_SDO,1);unsignedcharSPI_read(void)unsignedcharvsignb

12、it,r_data=O;tcc_set_gpio_direction(PIN_SDI,1);tcc_set_gpio_data(PIN_SDI,1);tcc_set_gpio_direction(PIN_SDI,O);for(vsignbit=0x80;vsignbit>O;vsignbit>>=1)tcc_set_gpio_data(PIN_SCLK,0);ndelay(20);if(tcc_get_gpio_data(PIN_SDI)r_data=r_data|vsignbit;tcc_set_gpio_data(PIN_SCLK,1);ndelay(20);return

13、r_data;staticvoidset_value()SPI_send(SPI_CMD,0xB9);SPI_send(SPI_DATA,OxFF);SPI_send(SPI_DATA,0x83);SPI_send(SPI_DATA,0x63);SPI_send(SPI_CMD,0xB1);SPI_send(SPI_DATA,0x81);SPI_send(SPI_DATA,0x30);SPI_send(SPI_DATA,0x07);SPI_send(SPI_DATA,0x34);SPI_send(SPI_DATA,0x02);SPI_send(SPI_DATA,0x13);SPI_send(S

14、PI_DATA,0x11);SPI_send(SPI_DATA,0x00);SPI_send(SPI_DATA,0x3A);SPI_send(SPI_DATA,0x42);SPI_send(SPI_DATA,0x3F);SPI_send(SPI_DATA,0x3F);SPI_send(SPI_CMD,0x11);mdelay(150);SPI_send(SPI_CMD,0x36);SPI_send(SPI_DATA,0x08);SPI_send(SPI_CMD,0x3A);SPI_send(SPI_DATA,0x77);SPI_send(SPI_CMD,0xB3);SPI_send(SPI_D

15、ATA,0x09);SPI_send(SPI_CMD,0xB4);SPI_send(SPI_DATA,0x08);SPI_send(SPI_DATA,0x12);SPI_send(SPI_DATA,0x72);SPI_send(SPI_DATA,0x12);SPI_send(SPI_DATA,0x06);SPI_send(SPI_DATA,0x03);SPI_send(SPI_DATA,0x54);SPI_send(SPI_DATA,0x03);SPI_send(SPI_DATA,0x4E);SPI_send(SPI_DATA,0x00);SPI_send(SPI_DATA,0x00);SPI

16、_send(SPI_CMD,0xBF);SPI_send(SPI_DATA,0x00);SPI_send(SPI_DATA,0x01);SPI_send(SPI_CMD,0xB6);SPI_send(SPI_DATA,0x00);SPI_send(SPI_CMD,0xCC);SPI_send(SPI_DATA,0x0A);mdelay(10);SPI_send(SPI_CMD,OxEO);SPI_send(SPI_DATA,0x00);SPI_send(SPI_DATA,0x40);SPI_send(SPI_DATA,0x42);SPI_send(SPI_DATA,0xC1);SPI_send

17、(SPI_DATA,0x4B);SPI_send(SPI_DATA,0xA7);SPI_send(SPI_DATA,0x06);SPI_send(SPI_DATA,0x0D);SPI_send(SPI_DATA,0x51);SPI_send(SPI_DATA,0x56);SPI_send(SPI_DATA,0x18);SPI_send(SPI_DATA,0x56);SPI_send(SPI_DATA,0x17);SPI_send(SPI_DATA,0x89);SPI_send(SPI_DATA,0x11);SPI_send(SPI_DATA,0x00);SPI_send(SPI_DATA,0x

18、40);SPI_send(SPI_DATA,0x42);SPI_send(SPI_DATA,0xC1);SPI_send(SPI_DATA,0x4B);SPI_send(SPI_DATA,0xA7);SPI_send(SPI_DATA,0x06);SPI_send(SPI_DATA,0x0D);SPI_send(SPI_DATA,0x51);SPI_send(SPI_DATA,0x56);SPI_send(SPI_DATA,0x18);SPI_send(SPI_DATA,0x56);SPI_send(SPI_DATA,0x17);SPI_send(SPI_DATA,0x89);SPI_send(SPI_DATA,0x11);mdelay(5);SPI_send(SPI_CMD,0x29);staticint_initspi_lcd_init(void)PLOG("Registerlcdspicontrol.'n");SPI_init();tcc_set_cs_data(0);ndelay(20);set_value();tcc_set_cs_data(1);return0;staticvoid_exitspi_lcd_exit(void)printk(KERNNFO"unregisterl