spi子系统之驱动SSD1306 OLED
接触Linux之前，曾以为读源码可以更快的学习软件，于是前几个博客都是一边读源码一边添加注释，甚至精读到每一行代码，实际上效果并不理想，看过之后就忘记了。主要原因是没理解透程序架构，各个模块之间的关系，如何联系在一起，再加上没有实例验证。后来逐渐发现，理解框架能达到事半功倍的效果，理解框架之后，反而代码也更容易看懂，甚至可以猜部分代码的作用，印象更加深刻。
理解SPI的驱动框架，还是从最基本的三个入口点触发，platform_device，platform_bus，platform_driver。
其中内核一提供给platform_bus，platform_driver在spi_s3c24xx_gpio.c和spi_s3c24xxc.c中，其中spi_s3c24xx_gpio.c用于IO模拟SPI （本例讨论的是IO模拟SPI），spi_s3c24xxc.c用于s3c24xx的硬件SPI。因此，我们需要动手写一个platform_device。
看看spi_s3c24xx_gpio.c做了些什么。
1 static int s3c2410_spigpio_probe(struct platform_device *dev) 2 { 3 ... ... 4 /* [cgw]: 分配一个SPI主机 */ 5 master = spi_alloc_master(&dev->dev, sizeof(struct s3c2410_spigpio)); 6 ... ... 7 8 sp = spi_master_get_devdata(master); 9 10 platform_set_drvdata(dev, sp);11 12 /* [cgw]: 分配与spi硬件相关的配置，如指定哪些IO为MISO,MOSI,SCLK,CS，SPI工作模式，最大时钟等等 */13 /* copy in the plkatform data */14 sp->info = dev->dev.platform_data;15 16 /* [cgw]: 提供实现SPI各种模式的时序的基本方法，和CS的激活方法 */17 /* setup spi bitbang adaptor */18 sp->bitbang.master = spi_master_get(master);19 sp->bitbang.chipselect = s3c2410_spigpio_chipselect;20 21 sp->bitbang.txrx_word[SPI_MODE_0] = s3c2410_spigpio_txrx_mode0;22 sp->bitbang.txrx_word[SPI_MODE_1] = s3c2410_spigpio_txrx_mode1;23 sp->bitbang.txrx_word[SPI_MODE_2] = s3c2410_spigpio_txrx_mode2;24 sp->bitbang.txrx_word[SPI_MODE_3] = s3c2410_spigpio_txrx_mode3;25 26 /* [cgw]: 配置相关io为输入输出 */27 /* set state of spi pins */28 s3c2410_gpio_setpin(sp->info->pin_clk, 0);29 s3c2410_gpio_setpin(sp->info->pin_mosi, 0);30 31 s3c2410_gpio_cfgpin(sp->info->pin_clk, S3C2410_GPIO_OUTPUT);32 s3c2410_gpio_cfgpin(sp->info->pin_mosi, S3C2410_GPIO_OUTPUT);33 s3c2410_gpio_cfgpin(sp->info->pin_miso, S3C2410_GPIO_INPUT);34 35 /* [cgw]: 设置spi的收发，如注册一个工作队列，收发时序的方法，8/16/32的spi数据等等 */36 ret = spi_bitbang_start(&sp->bitbang);37 ... ...38 39 /* [cgw]: 注册sp->info->board_size个spi设备，这几个spi设备都是挂接在统一spi总线上的 */40 /* register the chips to go with the board */41 for (i = 0; i < sp->info->board_size; i++) {42 dev_info(&dev->dev, "registering %p: %s\n",43 &sp->info->board_info[i],44 sp->info->board_info[i].modalias);45 46 sp->info->board_info[i].controller_data = sp;47 spi_new_device(master, sp->info->board_info + i);48 }49 ... ...50 }
- 注册了一个platform_driver
- 在s3c2410_spigpio_probe中，分配并注册了一个spi主机，并注册了挂接在这个SPI主机上的所有spi设备
要想s3c2410_spigpio_probe得到调用，即探测到有效的platform_device，我们需要一个与platform同名（"s3c24xx-spi-gpio"）的platform_device。
1 static struct spi_board_info board_info[1] = { 2 { 3 .modalias = "spi_ssd1306", /* [cgw]: spi设备名，和设备驱动名对应 */ 4 .bus_num = 0, /* [cgw]: spi总线号，即spi0 */ 5 .chip_select = 2, /* [cgw]: spi总线上的设备号,即spi0.2 */ 6 .max_speed_hz = 50000, /* [cgw]: spi时钟 */ 7 .mode = SPI_MODE_3, /* [cgw]: spi数据模式 */ 8 }, 9 };10 11 static struct s3c2410_spigpio_info spi_dev = {12 .pin_clk = S3C2410_GPG7,13 .pin_mosi = S3C2410_GPG5,14 .pin_miso = S3C2410_GPG6,15 .board_size = 1, /* [cgw]: 设置板上spi接口数量为1 */16 .board_info = &board_info[0],17 .chip_select = ssd1306_chip_select18 };19 20 static struct platform_device spi_platform_dev = {21 .name = "s3c24xx-spi-gpio", /* [cgw]: 设置平台设备名，和平台驱动名对应 */22 .id = -1,23 .dev = { 24 .release = spi_dev_release,25 .platform_data = (void *)&spi_dev, /* [cgw]: 通过platform_data传递spi_dev给平台驱动26 * 平台驱动可以访问spi_dev27 */28 },29 };30 31 static int spi_dev_init(void)32 {33 /* [cgw]: 注册spi_platform_dev平台设备 */34 platform_device_register(&spi_platform_dev);35 return 0;36 }
spi_bitbang.c提供了spi底层一些实现细节，注册工作队列（SPI数据的传送最终是通过调用工作队列实现的），spi工作模式，工作频率等。
1 int spi_bitbang_setup_transfer(struct spi_device *spi, struct spi_transfer *t) 2 { 3 struct spi_bitbang_cs *cs = spi->controller_state; 4 u8 bits_per_word; 5 u32 hz; 6 7 if (t) { 8 /* [cgw]: spi驱动指定几位数据模式，和传送速度 */ 9 bits_per_word = t->bits_per_word; 10 hz = t->speed_hz; 11 } else { 12 bits_per_word = 0; 13 hz = 0; 14 } 15 16 /* [cgw]: 根据spi位数，选择合适的时序 */ 17 /* spi_transfer level calls that work per-word */ 18 if (!bits_per_word) 19 bits_per_word = spi->bits_per_word; 20 if (bits_per_word <= 8) 21 cs->txrx_bufs = bitbang_txrx_8; 22 else if (bits_per_word <= 16) 23 cs->txrx_bufs = bitbang_txrx_16; 24 else if (bits_per_word <= 32) 25 cs->txrx_bufs = bitbang_txrx_32; 26 else 27 return -EINVAL; 28 29 /* [cgw]: 设置SCLK的时钟频率 */ 30 /* nsecs = (clock period)/2 */ 31 if (!hz) 32 hz = spi->max_speed_hz; 33 if (hz) { 34 cs->nsecs = (1000000000/2) / hz; 35 if (cs->nsecs > (MAX_UDELAY_MS * 1000 * 1000)) 36 return -EINVAL; 37 } 38 39 return 0; 40 } 41 42 int spi_bitbang_setup(struct spi_device *spi) 43 { 44 struct spi_bitbang_cs *cs = spi->controller_state; 45 struct spi_bitbang *bitbang; 46 int retval; 47 48 bitbang = spi_master_get_devdata(spi->master); 49 50 /* REVISIT: some systems will want to support devices using lsb-first 51 * bit encodings on the wire. In pure software that would be trivial, 52 * just bitbang_txrx_le_cphaX() routines shifting the other way, and 53 * some hardware controllers also have this support. 54 */ 55 /* [cgw]: 默认不支持LSB模式，要想使用LSB模式，只要bitbang_txrx_le_cphaX()改变移位的方向即可 */ 56 if ((spi->mode & SPI_LSB_FIRST) != 0) 57 return -EINVAL; 58 59 if (!cs) { 60 cs = kzalloc(sizeof *cs, GFP_KERNEL); 61 if (!cs) 62 return -ENOMEM; 63 spi->controller_state = cs; 64 } 65 66 /* [cgw]: 设置spi的默认位数 */ 67 if (!spi->bits_per_word) 68 spi->bits_per_word = 8; 69 70 /* per-word shift register access, in hardware or bitbanging */ 71 /* [cgw]: 设置spi的工作模式，四种 */ 72 cs->txrx_word = bitbang->txrx_word[spi->mode & (SPI_CPOL|SPI_CPHA)]; 73 if (!cs->txrx_word) 74 return -EINVAL; 75 76 /* [cgw]: 调用spi_bitbang_setup_transfer */ 77 retval = bitbang->setup_transfer(spi, NULL); 78 if (retval < 0) 79 return retval; 80 81 dev_dbg(&spi->dev, "%s, mode %d, %u bits/w, %u nsec/bit\n", 82 __FUNCTION__, spi->mode & (SPI_CPOL | SPI_CPHA), 83 spi->bits_per_word, 2 * cs->nsecs); 84 85 /* NOTE we _need_ to call chipselect() early, ideally with adapter 86 * setup, unless the hardware defaults cooperate to avoid confusion 87 * between normal (active low) and inverted chipselects. 88 */ 89 90 /* [cgw]: spi忙的话，通过改变CS的状态释放SPI */ 91 /* deselect chip (low or high) */ 92 spin_lock(&bitbang->lock); 93 if (!bitbang->busy) { 94 bitbang->chipselect(spi, BITBANG_CS_INACTIVE); 95 ndelay(cs->nsecs); 96 } 97 spin_unlock(&bitbang->lock); 98 99 return 0;100 }101 102 103 static int spi_bitbang_bufs(struct spi_device *spi, struct spi_transfer *t)104 {105 struct spi_bitbang_cs *cs = spi->controller_state;106 unsigned nsecs = cs->nsecs;107 108 /* [cgw]: 具体数据收发就是这里实现的 */109 return cs->txrx_bufs(spi, cs->txrx_word, nsecs, t);110 }111 112 int spi_bitbang_transfer(struct spi_device *spi, struct spi_message *m)113 {114 struct spi_bitbang *bitbang;115 unsigned long flags;116 int status = 0;117 118 m->actual_length = 0;119 m->status = -EINPROGRESS;120 121 bitbang = spi_master_get_devdata(spi->master);122 123 spin_lock_irqsave(&bitbang->lock, flags);124 if (!spi->max_speed_hz)125 status = -.NETDOWN;126 else {127 /* [cgw]: 入队一个工作到工作队列 */128 list_add_tail(&m->queue, &bitbang->queue);129 queue_work(bitbang->workqueue, &bitbang->work);130 }131 spin_unlock_irqrestore(&bitbang->lock, flags);132 133 return status;134 }135 136 int spi_bitbang_start(struct spi_bitbang *bitbang)137 {138 int status;139 140 if (!bitbang->master || !bitbang->chipselect)141 return -EINVAL;142 143 /* [cgw]: 注册一个工作队列 */144 INIT_WORK(&bitbang->work, bitbang_work);145 spin_lock_init(&bitbang->lock);146 INIT_LIST_HEAD(&bitbang->queue);147 148 /* [cgw]: 配置相关方法 */149 if (!bitbang->master->transfer)150 bitbang->master->transfer = spi_bitbang_transfer;151 if (!bitbang->txrx_bufs) {152 bitbang->use_dma = 0;153 bitbang->txrx_bufs = spi_bitbang_bufs;154 if (!bitbang->master->setup) {155 if (!bitbang->setup_transfer)156 bitbang->setup_transfer =157 spi_bitbang_setup_transfer;158 bitbang->master->setup = spi_bitbang_setup;159 bitbang->master->cleanup = spi_bitbang_cleanup;160 }161 } else if (!bitbang->master->setup)162 return -EINVAL;163 164 /* [cgw]: 创建一个单线程，用于调度工作队列 */165 /* this task is the only thing to touch the SPI bits */166 bitbang->busy = 0;167 bitbang->workqueue = create_singlethread_workqueue(168 bitbang->master->cdev.dev->bus_id);169 if (bitbang->workqueue == NULL) {170 status = -EBUSY;171 goto err1;172 }173 174 /* [cgw]: 注册一个spi主机 */175 /* driver may get busy before register() returns, especially176 * if someone registered boardinfo for devices177 */178 status = spi_register_master(bitbang->master);179 if (status < 0)180 goto err2;181 182 return status;183 184 err2:185 destroy_workqueue(bitbang->workqueue);186 err1:187 return status;188 }
因为在s3c2410_spigpio_probe中注册了spi的设备，因此我们还需为这些设备提供驱动，以被这些设备探测到，探测这些驱动的条件也是设备和驱动的名字同名，即spi_ssd1306。我们这里提供了一个ssd1306 OLED的驱动
1 static struct spi_driver spi_ssd1306_driver = { 2 .driver = { 3 .name = "spi_ssd1306", 4 .bus = &spi_bus_type, 5 .owner = THIS_MODULE, 6 }, 7 .probe = spi_ssd1306_probe, 8 .remove = __devexit_p(spi_ssd1306_remove), 9 };10 11 static int spi_ssd1306_init(void)12 {13 return spi_register_driver(&spi_ssd1306_driver);14 }
到这里，基本工作已经完成。怎样驱动ssd1306 OLED呢？
ssd1306 OLED的使用方法，请参考相关的手册。
本例提供的ssd1306 OLED驱动，只需要我们提供一个基本9位spi数据收发的接口即可。
static void ssd1306_write_byte(uint8_t chData, uint8_t chCmd) { struct spi_transfer t; struct spi_message m; uint16_t data = chData; /* [cgw]: 情况spi_transfer */ memset(&t,0,sizeof(struct spi_transfer)); /* [cgw]: 第9位表示前8位是命令还是数据，1：数据，0：命令 */ if (chCmd) { data |= (1 << 8); } else { data &= ~(1 << 8); } /* [cgw]: 要发送的数据 */ t.tx_buf = &data; /* [cgw]: 长度，2字节 */ t.len = 2; /* [cgw]: 9位spi */ t.bits_per_word = 9; //t.cs_change = 1; /* [cgw]: 把数据添加到收发列表，工作队列调度时会从收发队列中取出，并进行收发 * 注意这里并没有直接收发 */ spi_message_init(&m); spi_message_add_tail(&t, &m); spi_sync(spi_ssd1306_dev, &m);}
注意，在网上看到一些例子，用8位模式驱动ssd1306 OLED的，需要用DC的状态来表示数据或命令的，他们的做法如下：
1 void ssd1306_write_cmd(uint8_t cmd) 2 { 3 ssd1306_dc_clr(); 4 spi_write(cmd); 5 ssd1306_dc_set(); 6 } 7 8 void ssd1306_write_data(uint8_t data) 9 {10 ssd1306_dc_set();11 spi_write(data);12 ssd1306_dc_clr();13 }
我本人认为是不正确的，至少不符合这个spi框架的逻辑，因为spi数据的收发并不是直接在spi_write()实现，而是在工作队列bitbang_work()中实现。尽管这样仍然能驱动ssd1306 OLED，但理论上不应该这么做。要改的话应该改bitbang_work()中改，添加DC状态的控制。
1 static void bitbang_work(struct work_struct *work) 2 { 3 struct spi_bitbang *bitbang = 4 container_of(work, struct spi_bitbang, work); 5 unsigned long flags; 6 7 spin_lock_irqsave(&bitbang->lock, flags); 8 bitbang->busy = 1; 9 /* [cgw]: 队列不为空 */ 10 while (!list_empty(&bitbang->queue)) { 11 struct spi_message *m; 12 struct spi_device *spi; 13 unsigned nsecs; 14 struct spi_transfer *t = NULL; 15 unsigned tmp; 16 unsigned cs_change; 17 int status; 18 int (*setup_transfer)(struct spi_device *, 19 struct spi_transfer *); 20 21 /* [cgw]: 取出spi_message */ 22 m = container_of(bitbang->queue.next, struct spi_message, 23 queue); 24 /* [cgw]: 删除这个节点 */ 25 list_del_init(&m->queue); 26 /* [cgw]: 进入临界区 */ 27 spin_unlock_irqrestore(&bitbang->lock, flags); 28 29 /* FIXME this is made-up ... the correct value is known to 30 * word-at-a-time bitbang code, and presumably chipselect() 31 * should enforce these requirements too? 32 */ 33 nsecs = 100; 34 35 spi = m->spi; 36 tmp = 0; 37 cs_change = 1; 38 status = 0; 39 setup_transfer = NULL; 40 41 /* [cgw]: 历遍spi_message中的收发列表 */ 42 list_for_each_entry (t, &m->transfers, transfer_list) { 43 44 /* override or restore speed and wordsize */ 45 /* [cgw]: 如果驱动指定了spi速度，和位数，重新调用spi_bitbang_setup_transfer 46 * 更改默认设置 47 */ 48 if (t->speed_hz || t->bits_per_word) { 49 setup_transfer = bitbang->setup_transfer; 50 if (!setup_transfer) { 51 status = -ENOPROTOOPT; 52 break; 53 } 54 } 55 if (setup_transfer) { 56 status = setup_transfer(spi, t); 57 if (status < 0) 58 break; 59 } 60 61 /* set up default clock polarity, and activate chip; 62 * this implicitly updates clock and spi modes as 63 * previously recorded for this device via setup(). 64 * (and also deselects any other chip that might be 65 * selected ...) 66 */ 67 /* [cgw]: 激活spi */ 68 if (cs_change) { 69 bitbang->chipselect(spi, BITBANG_CS_ACTIVE); 70 ndelay(nsecs); 71 } 72 /* [cgw]: 驱动指定收发完一帧数据要不要改变恢复CS为空闲 */ 73 cs_change = t->cs_change; 74 /* [cgw]: 收发包为空，则无效 */ 75 if (!t->tx_buf && !t->rx_buf && t->len) { 76 status = -EINVAL; 77 break; 78 } 79 80 /* transfer data. the lower level code handles any 81 * new dma mappings it needs. our caller always gave 82 * us dma-safe buffers. 83 */ 84 if (t->len) { 85 /* REVISIT dma API still needs a designated 86 * DMA_ADDR_INVALID; ~0 might be better. 87 */ 88 if (!m->is_dma_mapped) 89 t->rx_dma = t->tx_dma = 0; 90 /* [cgw]: 这里才是真正的实现spi收发时序 */ 91 status = bitbang->txrx_bufs(spi, t); 92 } 93 if (status != t->len) { 94 if (status > 0) 95 status = -EMSGSIZE; 96 break; 97 } 98 m->actual_length += status; 99 status = 0;100 101 /* protocol tweaks before next transfer */102 if (t->delay_usecs)103 udelay(t->delay_usecs);104 105 /* [cgw]: 收发完一帧，不改变CS状态 */106 if (!cs_change)107 continue;108 109 /* [cgw]: 收发列表已经没有数据，结束 */110 if (t->transfer_list.next == &m->transfers)111 break;112 113 /* sometimes a short mid-message deselect of the chip114 * may be needed to terminate a mode or command115 */116 /* [cgw]: 释放spi */117 ndelay(nsecs);118 bitbang->chipselect(spi, BITBANG_CS_INACTIVE);119 ndelay(nsecs);120 }121 122 m->status = status;123 m->complete(m->context);124 125 /* restore speed and wordsize */126 /* [cgw]: 速度和位数恢复默认 */127 if (setup_transfer)128 setup_transfer(spi, NULL);129 130 /* normally deactivate chipselect ... unless no error and131 * cs_change has hinted that the next message will probably132 * be for this chip too.133 */134 if (!(status == 0 && cs_change)) {135 ndelay(nsecs);136 bitbang->chipselect(spi, BITBANG_CS_INACTIVE);137 ndelay(nsecs);138 }139 140 spin_lock_irqsave(&bitbang->lock, flags);141 }142 bitbang->busy = 0;143 /* [cgw]: 退出临界区 */144 spin_unlock_irqrestore(&bitbang->lock, flags);145 }
代码：
spi_platform_dev.c
1 #include <asm/arch/spi-gpio.h> 2 3 4 static struct spi_board_info board_info[1] = { 5 { 6 .modalias = "spi_ssd1306", /* [cgw]: spi设备名，和设备驱动名对应 */ 7 .bus_num = 0, /* [cgw]: spi总线号，即spi0 */ 8 .chip_select = 2, /* [cgw]: spi总线上的设备号,即spi0.2 */ 9 .max_speed_hz = 50000, /* [cgw]: spi时钟 */10 .mode = SPI_MODE_3, /* [cgw]: spi数据模式 */11 },12 };13 14 15 static void ssd1306_chip_select(struct s3c2410_spigpio_info *spi, int cs)16 {17 /* [cgw]: 选中设备号为2的spi设备 */18 if (spi->board_info->chip_select == 2) {19 s3c2410_gpio_cfgpin(S3C2410_GPG2, S3C2410_GPIO_OUTPUT);20 /* [cgw]: 选中设备 */21 if (BITBANG_CS_ACTIVE == cs) {22 s3c2410_gpio_setpin(S3C2410_GPG2, 0);23 /* [cgw]: 释放设备 */24 } else if (BITBANG_CS_INACTIVE == cs) {25 s3c2410_gpio_setpin(S3C2410_GPG2, 1);26 }27 }28 }29 30 /* [cgw]: */31 static struct s3c2410_spigpio_info spi_dev = {32 .pin_clk = S3C2410_GPG7,33 .pin_mosi = S3C2410_GPG5,34 .pin_miso = S3C2410_GPG6,35 .board_size = 1, /* [cgw]: 设置板上spi接口数量为1 */36 .board_info = &board_info[0],37 .chip_select = ssd1306_chip_select38 };39 40 static void spi_dev_release(struct device * dev)41 {42 printk("spi_dev_release! \n");43 }44 45 /* [cgw]: 分配一个平台设备 */46 static struct platform_device spi_platform_dev = {47 .name = "s3c24xx-spi-gpio", /* [cgw]: 设置平台设备名，和平台驱动名对应 */48 .id = -1,49 .dev = { 50 .release = spi_dev_release,51 .platform_data = (void *)&spi_dev, /* [cgw]: 通过platform_data传递spi_dev给平台驱动52 * 平台驱动可以访问spi_dev53 */54 },55 };56 57 58 static int spi_dev_init(void)59 {60 /* [cgw]: 注册spi_platform_dev平台设备 */61 platform_device_register(&spi_platform_dev);62 return 0;63 }64 65 static void spi_dev_exit(void)66 {67 /* [cgw]: 注销spi_platform_dev平台设备 */68 platform_device_unregister(&spi_platform_dev);69 }70 71 module_init(spi_dev_init);72 module_exit(spi_dev_exit);73 74 MODULE_LICENSE("GPL");
spi_ssd1306_drv.c
1 #include <linux/init.h> 2 #include <linux/module.h> 3 #include <linux/device.h> 4 #include <linux/interrupt.h> 5 #include <linux/interrupt.h> 6 #include <linux/mtd/mtd.h> 7 #include <linux/mtd/partitions.h> 8 #include <linux/spi/spi.h> 9 10 #define SSD1306_CMD 0 11 #define SSD1306_DAT 1 12 13 #define SSD1306_WIDTH 128 14 #define SSD1306_HEIGHT 64 15 16 static uint8_t s_chDispalyBuffer[128][8]; 17 18 const uint8_t c_chFont1608[95][16] = { 19 {0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},/*" ",0*/ 20 {0x00,0x00,0x00,0x00,0x00,0x00,0x1F,0xCC,0x00,0x0C,0x00,0x00,0x00,0x00,0x00,0x00},/*"!",1*/ 21 {0x00,0x00,0x08,0x00,0x30,0x00,0x60,0x00,0x08,0x00,0x30,0x00,0x60,0x00,0x00,0x00},/*""",2*/ 22 {0x02,0x20,0x03,0xFC,0x1E,0x20,0x02,0x20,0x03,0xFC,0x1E,0x20,0x02,0x20,0x00,0x00},/*"#",3*/ 23 {0x00,0x00,0x0E,0x18,0x11,0x04,0x3F,0xFF,0x10,0x84,0x0C,0x78,0x00,0x00,0x00,0x00},/*"$",4*/ 24 {0x0F,0x00,0x10,0x84,0x0F,0x38,0x00,0xC0,0x07,0x78,0x18,0x84,0x00,0x78,0x00,0x00},/*"%",5*/ 25 {0x00,0x78,0x0F,0x84,0x10,0xC4,0x11,0x24,0x0E,0x98,0x00,0xE4,0x00,0x84,0x00,0x08},/*"&",6*/ 26 {0x08,0x00,0x68,0x00,0x70,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},/*"'",7*/ 27 {0x00,0x00,0x00,0x00,0x00,0x00,0x07,0xE0,0x18,0x18,0x20,0x04,0x40,0x02,0x00,0x00},/*"(",8*/ 28 {0x00,0x00,0x40,0x02,0x20,0x04,0x18,0x18,0x07,0xE0,0x00,0x00,0x00,0x00,0x00,0x00},/*")",9*/ 29 {0x02,0x40,0x02,0x40,0x01,0x80,0x0F,0xF0,0x01,0x80,0x02,0x40,0x02,0x40,0x00,0x00},/*"*",10*/ 30 {0x00,0x80,0x00,0x80,0x00,0x80,0x0F,0xF8,0x00,0x80,0x00,0x80,0x00,0x80,0x00,0x00},/*"+",11*/ 31 {0x00,0x01,0x00,0x0D,0x00,0x0E,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},/*",",12*/ 32 {0x00,0x00,0x00,0x80,0x00,0x80,0x00,0x80,0x00,0x80,0x00,0x80,0x00,0x80,0x00,0x80},/*"-",13*/ 33 {0x00,0x00,0x00,0x0C,0x00,0x0C,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},/*".",14*/ 34 {0x00,0x00,0x00,0x06,0x00,0x18,0x00,0x60,0x01,0x80,0x06,0x00,0x18,0x00,0x20,0x00},/*"/",15*/ 35 {0x00,0x00,0x07,0xF0,0x08,0x08,0x10,0x04,0x10,0x04,0x08,0x08,0x07,0xF0,0x00,0x00},/*"0",16*/ 36 {0x00,0x00,0x08,0x04,0x08,0x04,0x1F,0xFC,0x00,0x04,0x00,0x04,0x00,0x00,0x00,0x00},/*"1",17*/ 37 {0x00,0x00,0x0E,0x0C,0x10,0x14,0x10,0x24,0x10,0x44,0x11,0x84,0x0E,0x0C,0x00,0x00},/*"2",18*/ 38 {0x00,0x00,0x0C,0x18,0x10,0x04,0x11,0x04,0x11,0x04,0x12,0x88,0x0C,0x70,0x00,0x00},/*"3",19*/ 39 {0x00,0x00,0x00,0xE0,0x03,0x20,0x04,0x24,0x08,0x24,0x1F,0xFC,0x00,0x24,0x00,0x00},/*"4",20*/ 40 {0x00,0x00,0x1F,0x98,0x10,0x84,0x11,0x04,0x11,0x04,0x10,0x88,0x10,0x70,0x00,0x00},/*"5",21*/ 41 {0x00,0x00,0x07,0xF0,0x08,0x88,0x11,0x04,0x11,0x04,0x18,0x88,0x00,0x70,0x00,0x00},/*"6",22*/ 42 {0x00,0x00,0x1C,0x00,0x10,0x00,0x10,0xFC,0x13,0x00,0x1C,0x00,0x10,0x00,0x00,0x00},/*"7",23*/ 43 {0x00,0x00,0x0E,0x38,0x11,0x44,0x10,0x84,0x10,0x84,0x11,0x44,0x0E,0x38,0x00,0x00},/*"8",24*/ 44 {0x00,0x00,0x07,0x00,0x08,0x8C,0x10,0x44,0x10,0x44,0x08,0x88,0x07,0xF0,0x00,0x00},/*"9",25*/ 45 {0x00,0x00,0x00,0x00,0x00,0x00,0x03,0x0C,0x03,0x0C,0x00,0x00,0x00,0x00,0x00,0x00},/*":",26*/ 46 {0x00,0x00,0x00,0x00,0x00,0x01,0x01,0x06,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},/*";",27*/ 47 {0x00,0x00,0x00,0x80,0x01,0x40,0x02,0x20,0x04,0x10,0x08,0x08,0x10,0x04,0x00,0x00},/*"<",28*/ 48 {0x02,0x20,0x02,0x20,0x02,0x20,0x02,0x20,0x02,0x20,0x02,0x20,0x02,0x20,0x00,0x00},/*"=",29*/ 49 {0x00,0x00,0x10,0x04,0x08,0x08,0x04,0x10,0x02,0x20,0x01,0x40,0x00,0x80,0x00,0x00},/*">",30*/ 50 {0x00,0x00,0x0E,0x00,0x12,0x00,0x10,0x0C,0x10,0x6C,0x10,0x80,0x0F,0x00,0x00,0x00},/*"?",31*/ 51 {0x03,0xE0,0x0C,0x18,0x13,0xE4,0x14,0x24,0x17,0xC4,0x08,0x28,0x07,0xD0,0x00,0x00},/*"@",32*/ 52 {0x00,0x04,0x00,0x3C,0x03,0xC4,0x1C,0x40,0x07,0x40,0x00,0xE4,0x00,0x1C,0x00,0x04},/*"A",33*/ 53 {0x10,0x04,0x1F,0xFC,0x11,0x04,0x11,0x04,0x11,0x04,0x0E,0x88,0x00,0x70,0x00,0x00},/*"B",34*/ 54 {0x03,0xE0,0x0C,0x18,0x10,0x04,0x10,0x04,0x10,0x04,0x10,0x08,0x1C,0x10,0x00,0x00},/*"C",35*/ 55 {0x10,0x04,0x1F,0xFC,0x10,0x04,0x10,0x04,0x10,0x04,0x08,0x08,0x07,0xF0,0x00,0x00},/*"D",36*/ 56 {0x10,0x04,0x1F,0xFC,0x11,0x04,0x11,0x04,0x17,0xC4,0x10,0x04,0x08,0x18,0x00,0x00},/*"E",37*/ 57 {0x10,0x04,0x1F,0xFC,0x11,0x04,0x11,0x00,0x17,0xC0,0x10,0x00,0x08,0x00,0x00,0x00},/*"F",38*/ 58 {0x03,0xE0,0x0C,0x18,0x10,0x04,0x10,0x04,0x10,0x44,0x1C,0x78,0x00,0x40,0x00,0x00},/*"G",39*/ 59 {0x10,0x04,0x1F,0xFC,0x10,0x84,0x00,0x80,0x00,0x80,0x10,0x84,0x1F,0xFC,0x10,0x04},/*"H",40*/ 60 {0x00,0x00,0x10,0x04,0x10,0x04,0x1F,0xFC,0x10,0x04,0x10,0x04,0x00,0x00,0x00,0x00},/*"I",41*/ 61 {0x00,0x03,0x00,0x01,0x10,0x01,0x10,0x01,0x1F,0xFE,0x10,0x00,0x10,0x00,0x00,0x00},/*"J",42*/ 62 {0x10,0x04,0x1F,0xFC,0x11,0x04,0x03,0x80,0x14,0x64,0x18,0x1C,0x10,0x04,0x00,0x00},/*"K",43*/ 63 {0x10,0x04,0x1F,0xFC,0x10,0x04,0x00,0x04,0x00,0x04,0x00,0x04,0x00,0x0C,0x00,0x00},/*"L",44*/ 64 {0x10,0x04,0x1F,0xFC,0x1F,0x00,0x00,0xFC,0x1F,0x00,0x1F,0xFC,0x10,0x04,0x00,0x00},/*"M",45*/ 65 {0x10,0x04,0x1F,0xFC,0x0C,0x04,0x03,0x00,0x00,0xE0,0x10,0x18,0x1F,0xFC,0x10,0x00},/*"N",46*/ 66 {0x07,0xF0,0x08,0x08,0x10,0x04,0x10,0x04,0x10,0x04,0x08,0x08,0x07,0xF0,0x00,0x00},/*"O",47*/ 67 {0x10,0x04,0x1F,0xFC,0x10,0x84,0x10,0x80,0x10,0x80,0x10,0x80,0x0F,0x00,0x00,0x00},/*"P",48*/ 68 {0x07,0xF0,0x08,0x18,0x10,0x24,0x10,0x24,0x10,0x1C,0x08,0x0A,0x07,0xF2,0x00,0x00},/*"Q",49*/ 69 {0x10,0x04,0x1F,0xFC,0x11,0x04,0x11,0x00,0x11,0xC0,0x11,0x30,0x0E,0x0C,0x00,0x04},/*"R",50*/ 70 {0x00,0x00,0x0E,0x1C,0x11,0x04,0x10,0x84,0x10,0x84,0x10,0x44,0x1C,0x38,0x00,0x00},/*"S",51*/ 71 {0x18,0x00,0x10,0x00,0x10,0x04,0x1F,0xFC,0x10,0x04,0x10,0x00,0x18,0x00,0x00,0x00},/*"T",52*/ 72 {0x10,0x00,0x1F,0xF8,0x10,0x04,0x00,0x04,0x00,0x04,0x10,0x04,0x1F,0xF8,0x10,0x00},/*"U",53*/ 73 {0x10,0x00,0x1E,0x00,0x11,0xE0,0x00,0x1C,0x00,0x70,0x13,0x80,0x1C,0x00,0x10,0x00},/*"V",54*/ 74 {0x1F,0xC0,0x10,0x3C,0x00,0xE0,0x1F,0x00,0x00,0xE0,0x10,0x3C,0x1F,0xC0,0x00,0x00},/*"W",55*/ 75 {0x10,0x04,0x18,0x0C,0x16,0x34,0x01,0xC0,0x01,0xC0,0x16,0x34,0x18,0x0C,0x10,0x04},/*"X",56*/ 76 {0x10,0x00,0x1C,0x00,0x13,0x04,0x00,0xFC,0x13,0x04,0x1C,0x00,0x10,0x00,0x00,0x00},/*"Y",57*/ 77 {0x08,0x04,0x10,0x1C,0x10,0x64,0x10,0x84,0x13,0x04,0x1C,0x04,0x10,0x18,0x00,0x00},/*"Z",58*/ 78 {0x00,0x00,0x00,0x00,0x00,0x00,0x7F,0xFE,0x40,0x02,0x40,0x02,0x40,0x02,0x00,0x00},/*"[",59*/ 79 {0x00,0x00,0x30,0x00,0x0C,0x00,0x03,0x80,0x00,0x60,0x00,0x1C,0x00,0x03,0x00,0x00},/*"\",60*/ 80 {0x00,0x00,0x40,0x02,0x40,0x02,0x40,0x02,0x7F,0xFE,0x00,0x00,0x00,0x00,0x00,0x00},/*"]",61*/ 81 {0x00,0x00,0x00,0x00,0x20,0x00,0x40,0x00,0x40,0x00,0x40,0x00,0x20,0x00,0x00,0x00},/*"^",62*/ 82 {0x00,0x01,0x00,0x01,0x00,0x01,0x00,0x01,0x00,0x01,0x00,0x01,0x00,0x01,0x00,0x01},/*"_",63*/ 83 {0x00,0x00,0x40,0x00,0x40,0x00,0x20,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},/*"`",64*/ 84 {0x00,0x00,0x00,0x98,0x01,0x24,0x01,0x44,0x01,0x44,0x01,0x44,0x00,0xFC,0x00,0x04},/*"a",65*/ 85 {0x10,0x00,0x1F,0xFC,0x00,0x88,0x01,0x04,0x01,0x04,0x00,0x88,0x00,0x70,0x00,0x00},/*"b",66*/ 86 {0x00,0x00,0x00,0x70,0x00,0x88,0x01,0x04,0x01,0x04,0x01,0x04,0x00,0x88,0x00,0x00},/*"c",67*/ 87 {0x00,0x00,0x00,0x70,0x00,0x88,0x01,0x04,0x01,0x04,0x11,0x08,0x1F,0xFC,0x00,0x04},/*"d",68*/ 88 {0x00,0x00,0x00,0xF8,0x01,0x44,0x01,0x44,0x01,0x44,0x01,0x44,0x00,0xC8,0x00,0x00},/*"e",69*/ 89 {0x00,0x00,0x01,0x04,0x01,0x04,0x0F,0xFC,0x11,0x04,0x11,0x04,0x11,0x00,0x18,0x00},/*"f",70*/ 90 {0x00,0x00,0x00,0xD6,0x01,0x29,0x01,0x29,0x01,0x29,0x01,0xC9,0x01,0x06,0x00,0x00},/*"g",71*/ 91 {0x10,0x04,0x1F,0xFC,0x00,0x84,0x01,0x00,0x01,0x00,0x01,0x04,0x00,0xFC,0x00,0x04},/*"h",72*/ 92 {0x00,0x00,0x01,0x04,0x19,0x04,0x19,0xFC,0x00,0x04,0x00,0x04,0x00,0x00,0x00,0x00},/*"i",73*/ 93 {0x00,0x00,0x00,0x03,0x00,0x01,0x01,0x01,0x19,0x01,0x19,0xFE,0x00,0x00,0x00,0x00},/*"j",74*/ 94 {0x10,0x04,0x1F,0xFC,0x00,0x24,0x00,0x40,0x01,0xB4,0x01,0x0C,0x01,0x04,0x00,0x00},/*"k",75*/ 95 {0x00,0x00,0x10,0x04,0x10,0x04,0x1F,0xFC,0x00,0x04,0x00,0x04,0x00,0x00,0x00,0x00},/*"l",76*/ 96 {0x01,0x04,0x01,0xFC,0x01,0x04,0x01,0x00,0x01,0xFC,0x01,0x04,0x01,0x00,0x00,0xFC},/*"m",77*/ 97 {0x01,0x04,0x01,0xFC,0x00,0x84,0x01,0x00,0x01,0x00,0x01,0x04,0x00,0xFC,0x00,0x04},/*"n",78*/ 98 {0x00,0x00,0x00,0xF8,0x01,0x04,0x01,0x04,0x01,0x04,0x01,0x04,0x00,0xF8,0x00,0x00},/*"o",79*/ 99 {0x01,0x01,0x01,0xFF,0x00,0x85,0x01,0x04,0x01,0x04,0x00,0x88,0x00,0x70,0x00,0x00},/*"p",80*/100 {0x00,0x00,0x00,0x70,0x00,0x88,0x01,0x04,0x01,0x04,0x01,0x05,0x01,0xFF,0x00,0x01},/*"q",81*/101 {0x01,0x04,0x01,0x04,0x01,0xFC,0x00,0x84,0x01,0x04,0x01,0x00,0x01,0x80,0x00,0x00},/*"r",82*/102 {0x00,0x00,0x00,0xCC,0x01,0x24,0x01,0x24,0x01,0x24,0x01,0x24,0x01,0x98,0x00,0x00},/*"s",83*/103 {0x00,0x00,0x01,0x00,0x01,0x00,0x07,0xF8,0x01,0x04,0x01,0x04,0x00,0x00,0x00,0x00},/*"t",84*/104 {0x01,0x00,0x01,0xF8,0x00,0x04,0x00,0x04,0x00,0x04,0x01,0x08,0x01,0xFC,0x00,0x04},/*"u",85*/105 {0x01,0x00,0x01,0x80,0x01,0x70,0x00,0x0C,0x00,0x10,0x01,0x60,0x01,0x80,0x01,0x00},/*"v",86*/106 {0x01,0xF0,0x01,0x0C,0x00,0x30,0x01,0xC0,0x00,0x30,0x01,0x0C,0x01,0xF0,0x01,0x00},/*"w",87*/107 {0x00,0x00,0x01,0x04,0x01,0x8C,0x00,0x74,0x01,0x70,0x01,0x8C,0x01,0x04,0x00,0x00},/*"x",88*/108 {0x01,0x01,0x01,0x81,0x01,0x71,0x00,0x0E,0x00,0x18,0x01,0x60,0x01,0x80,0x01,0x00},/*"y",89*/109 {0x00,0x00,0x01,0x84,0x01,0x0C,0x01,0x34,0x01,0x44,0x01,0x84,0x01,0x0C,0x00,0x00},/*"z",90*/110 {0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x01,0x00,0x3E,0xFC,0x40,0x02,0x40,0x02},/*"{",91*/111 {0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xFF,0xFF,0x00,0x00,0x00,0x00,0x00,0x00},/*"|",92*/112 {0x00,0x00,0x40,0x02,0x40,0x02,0x3E,0xFC,0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x00},/*"}",93*/113 {0x00,0x00,0x60,0x00,0x80,0x00,0x80,0x00,0x40,0x00,0x40,0x00,0x20,0x00,0x20,0x00},/*"~",94*/114 };115 116 struct spi_device *spi_ssd1306_dev;117 118 static void ssd1306_write_byte(uint8_t chData, uint8_t chCmd) 119 {120 struct spi_transfer t;121 struct spi_message m;122 123 uint16_t data = chData;124 125 memset(&t,0,sizeof(struct spi_transfer));126 127 if (chCmd) {128 data |= (1 << 8);129 } else {130 data &= ~(1 << 8);131 }132 133 t.tx_buf = &data;134 t.len = 2;135 t.bits_per_word = 9;136 //t.cs_change = 1;137 spi_message_init(&m);138 spi_message_add_tail(&t, &m);139 spi_sync(spi_ssd1306_dev, &m);140 }141 142 143 void ssd1306_display_on(void)144 {145 ssd1306_write_byte(0x8D, SSD1306_CMD); 146 ssd1306_write_byte(0x14, SSD1306_CMD); 147 ssd1306_write_byte(0xAF, SSD1306_CMD); 148 }149 150 /**151 * @brief OLED turns off152 * 153 * @param None154 * 155 * @retval None156 **/157 void ssd1306_display_off(void)158 {159 ssd1306_write_byte(0x8D, SSD1306_CMD); 160 ssd1306_write_byte(0x10, SSD1306_CMD); 161 ssd1306_write_byte(0xAE, SSD1306_CMD); 162 }163 164 void ssd1306_refresh_gram(void)165 {166 uint8_t i, j;167 168 for (i = 0; i < 8; i ++) { 169 ssd1306_write_byte(0xB0 + i, SSD1306_CMD); 170 ssd1306_write_byte(0x02, SSD1306_CMD); 171 ssd1306_write_byte(0x10, SSD1306_CMD); 172 for (j = 0; j < 128; j ++) {173 ssd1306_write_byte(s_chDispalyBuffer[j][i], SSD1306_DAT); 174 }175 } 176 }177 178 179 void ssd1306_clear_screen(uint8_t chFill) 180 { 181 memset(s_chDispalyBuffer,chFill, sizeof(s_chDispalyBuffer));182 ssd1306_refresh_gram();183 }184 185 /**186 * @brief Draws a piont on the screen187 * 188 * @param chXpos: Specifies the X position189 * @param chYpos: Specifies the Y position190 * @param chPoint: 0: the point turns off 1: the piont turns on 191 * 192 * @retval None193 **/194 195 void ssd1306_draw_point(uint8_t chXpos, uint8_t chYpos, uint8_t chPoint)196 {197 uint8_t chPos, chBx, chTemp = 0;198 199 if (chXpos > 127 || chYpos > 63) {200 return;201 }202 chPos = 7 - chYpos / 8; // 203 chBx = chYpos % 8;204 chTemp = 1 << (7 - chBx);205 206 if (chPoint) {207 s_chDispalyBuffer[chXpos][chPos] |= chTemp;208 209 } else {210 s_chDispalyBuffer[chXpos][chPos] &= ~chTemp;211 }212 }213 214 /**215 * @brief Fills a rectangle216 * 217 * @param chXpos1: Specifies the X position 1 (X top left position)218 * @param chYpos1: Specifies the Y position 1 (Y top left position)219 * @param chXpos2: Specifies the X position 2 (X bottom right position)220 * @param chYpos3: Specifies the Y position 2 (Y bottom right position)221 * 222 * @retval 223 **/224 225 void ssd1306_fill_screen(uint8_t chXpos1, uint8_t chYpos1, uint8_t chXpos2, uint8_t chYpos2, uint8_t chDot) 226 { 227 uint8_t chXpos, chYpos; 228 229 for (chXpos = chXpos1; chXpos <= chXpos2; chXpos ++) {230 for (chYpos = chYpos1; chYpos <= chYpos2; chYpos ++) {231 ssd1306_draw_point(chXpos, chYpos, chDot);232 }233 } 234 235 ssd1306_refresh_gram();236 }237 238 239 /**240 * @brief Displays one character at the specified position 241 * 242 * @param chXpos: Specifies the X position243 * @param chYpos: Specifies the Y position244 * @param chSize: 245 * @param chMode246 * @retval 247 **/248 void ssd1306_display_char(uint8_t chXpos, uint8_t chYpos, uint8_t chChr, uint8_t chSize, uint8_t chMode)249 { 250 uint8_t i, j;251 uint8_t chTemp, chYpos0 = chYpos;252 253 chChr = chChr - ' '; 254 for (i = 0; i < chSize; i ++) { 255 if (chMode) {256 chTemp = c_chFont1608[chChr][i];257 } else {258 chTemp = ~c_chFont1608[chChr][i];259 }260 261 for (j = 0; j < 8; j ++) {262 if (chTemp & 0x80) {263 ssd1306_draw_point(chXpos, chYpos, 1);264 } else {265 ssd1306_draw_point(chXpos, chYpos, 0);266 }267 chTemp <<= 1;268 chYpos ++;269 270 if ((chYpos - chYpos0) == chSize) {271 chYpos = chYpos0;272 chXpos ++;273 break;274 }275 } 276 } 277 } 278 279 /**280 * @brief Displays a string on the screen281 * 282 * @param chXpos: Specifies the X position283 * @param chYpos: Specifies the Y position284 * @param pchString: Pointer to a string to display on the screen 285 * 286 * @retval None287 **/288 void ssd1306_display_string(uint8_t chXpos, uint8_t chYpos, const uint8_t *pchString, uint8_t chSize, uint8_t chMode)289 {290 while (*pchString != '\0') { 291 if (chXpos > (SSD1306_WIDTH - chSize / 2)) {292 chXpos = 0;293 chYpos += chSize;294 if (chYpos > (SSD1306_HEIGHT - chSize)) {295 chYpos = chXpos = 0;296 ssd1306_clear_screen(0x00);297 }298 }299 300 ssd1306_display_char(chXpos, chYpos, *pchString, chSize, chMode);301 chXpos += chSize / 2;302 pchString ++;303 }304 }305 306 void ssd1306_init(void)307 {308 ssd1306_write_byte(0xAE, SSD1306_CMD);//--turn off oled panel309 ssd1306_write_byte(0x00, SSD1306_CMD);//---set low column address310 ssd1306_write_byte(0x10, SSD1306_CMD);//---set high column address311 ssd1306_write_byte(0x40, SSD1306_CMD);//--set start line address Set Mapping RAM Display Start Line (0x00~0x3F)312 ssd1306_write_byte(0x81, SSD1306_CMD);//--set contrast control register313 ssd1306_write_byte(0xCF, SSD1306_CMD);// Set SEG Output Current Brightness314 ssd1306_write_byte(0xA1, SSD1306_CMD);//--Set SEG/Column Mapping 315 ssd1306_write_byte(0xC0, SSD1306_CMD);//Set COM/Row Scan Direction 316 ssd1306_write_byte(0xA6, SSD1306_CMD);//--set normal display317 ssd1306_write_byte(0xA8, SSD1306_CMD);//--set multiplex ratio(1 to 64)318 ssd1306_write_byte(0x3f, SSD1306_CMD);//--1/64 duty319 ssd1306_write_byte(0xD3, SSD1306_CMD);//-set display offset Shift Mapping RAM Counter (0x00~0x3F)320 ssd1306_write_byte(0x00, SSD1306_CMD);//-not offset321 ssd1306_write_byte(0xd5, SSD1306_CMD);//--set display clock divide ratio/oscillator frequency322 ssd1306_write_byte(0x80, SSD1306_CMD);//--set divide ratio, Set Clock as 100 Frames/Sec323 ssd1306_write_byte(0xD9, SSD1306_CMD);//--set pre-charge period324 ssd1306_write_byte(0xF1, SSD1306_CMD);//Set Pre-Charge as 15 Clocks & Discharge as 1 Clock325 ssd1306_write_byte(0xDA, SSD1306_CMD);//--set com pins hardware configuration326 ssd1306_write_byte(0x12, SSD1306_CMD);327 ssd1306_write_byte(0xDB, SSD1306_CMD);//--set vcomh328 ssd1306_write_byte(0x40, SSD1306_CMD);//Set VCOM Deselect Level329 ssd1306_write_byte(0x20, SSD1306_CMD);//-Set Page Addressing Mode (0x00/0x01/0x02)330 ssd1306_write_byte(0x02, SSD1306_CMD);//331 ssd1306_write_byte(0x8D, SSD1306_CMD);//--set Charge Pump enable/disable332 ssd1306_write_byte(0x14, SSD1306_CMD);//--set(0x10) disable333 ssd1306_write_byte(0xA4, SSD1306_CMD);// Disable Entire Display On (0xa4/0xa5)334 ssd1306_write_byte(0xA6, SSD1306_CMD);// Disable Inverse Display On (0xa6/a7) 335 ssd1306_write_byte(0xAF, SSD1306_CMD);//--turn on oled panel336 337 ssd1306_display_on();338 ssd1306_clear_screen(0xff);339 340 }341 342 343 static int __devinit spi_ssd1306_probe(struct spi_device *spi)344 {345 printk("spi_ssd1306_probe\n");346 spi_ssd1306_dev = spi;347 spi_ssd1306_dev->bits_per_word = 9;348 349 ssd1306_init();350 ssd1306_clear_screen(0x00);351 ssd1306_display_off();352 353 ssd1306_display_string(18, 0, "hello, Linux!", 16, 1);354 ssd1306_display_string(0, 16, "this is a spi driver demo!", 16, 1);355 ssd1306_refresh_gram();356 ssd1306_display_on();357 358 return 0;359 }360 361 362 static int __devexit spi_ssd1306_remove(struct spi_device *spi)363 {364 printk("ssd1306_remove\n");365 366 ssd1306_clear_screen(0x00);367 ssd1306_display_off();368 return 0;369 }370 371 372 static struct spi_driver spi_ssd1306_driver = {373 .driver = {374 .name = "spi_ssd1306",375 .bus = &spi_bus_type,376 .owner = THIS_MODULE,377 },378 .probe = spi_ssd1306_probe,379 .remove = __devexit_p(spi_ssd1306_remove),380 };381 382 383 static int spi_ssd1306_init(void)384 {385 return spi_register_driver(&spi_ssd1306_driver);386 }387 388 389 static void spi_ssd1306_exit(void)390 {391 spi_unregister_driver(&spi_ssd1306_driver);392 }393 394 395 module_init(spi_ssd1306_init);396 module_exit(spi_ssd1306_exit);397 398 MODULE_LICENSE("GPL");
makefile
1 KERN_DIR = /work/system/linux-2.6.22.6 2 3 all: 4 make -C $(KERN_DIR) M=`pwd` modules 5 6 clean: 7 make -C $(KERN_DIR) M=`pwd` modules clean 8 rm -rf modules.order 9 10 obj-m += spi_platform_dev.o11 obj-m += spi_s3c24xx_gpio.o12 obj-m += spi_bitbang.o13 obj-m += spi_ssd1306_drv.o
实验现象：
images/loading.gif' data-original="http://images2015.cnblogs.com/blog/994502/201611/994502-20161120131644467-550724234.png" >
原标题：spi子系统之驱动SSD1306 OLED
关键词：
我知道了 