lk SPI驱动
1. 初始化时钟
在lk中，我们是从kmain开始执行下来的，而执行顺序则是先初始化时钟，也就是在platform_early_init函数中开始执行的：
在这里我们需要修改这个函数中的platform_clock_init();，我们来这里看这个函数，平台为msm8909：
void platform_clock_init(void)
{
clk_init(msm_clocks_msm8909, ARRAY_SIZE(msm_clocks_msm8909));
}
msm_clocks_msm8909这个数组增加可以参考链接来增加，之后会提供patch来显示，相关寄存器文档参考80_NU767_1_H_Linux BAM Low-Speed Peripherals Configuration and Debug Guide.pdf；
同样的道理先从aboot_init分析起，进入target_display_init函数中来：
target_display_init(device.display_panel); 这里进行屏幕的初始化。
void target_display_init(const char *panel_name)
{
uint32_t panel_loop = 0;
uint32_t ret = 0;
panel_name += strspn(panel_name, " ");
if (!strcmp(panel_name, NO_PANEL_CONFIG) || !strcmp(panel_name, SIM_VIDEO_PANEL)
|| !strcmp(panel_name, SIM_CMD_PANEL)) {
dprintf(INFO, "Selected %s: Skip panel configuration
", panel_name);
return;
}
dprintf(INFO, "panel_name is %s
", panel_name);
do {
target_force_cont_splash_disable(false);
ret = gcdb_display_init(panel_name, MDP_REV_305, MIPI_FB_ADDR);
if (!ret || ret == ERR_NOT_SUPPORTED) {
break;
} else {
target_force_cont_splash_disable(true);
msm_display_off();
}
} while (++panel_loop <= oem_panel_max_auto_detect_panels());
}
gcdb_display_init调用pan_type = oem_panel_select(panel_name, &panelstruct, &(panel.panel_info), &dsi_video_mode_phy_db)，选择具体的屏幕；
int gcdb_display_init(const char *panel_name, uint32_t rev, void *base)
{
int ret = NO_ERROR;
int pan_type;
pan_type = oem_panel_select(panel_name, &panelstruct, &(panel.panel_info),
&dsi_video_mode_phy_db);
if (pan_type == PANEL_TYPE_DSI) {
init_platform_data();
if (dsi_panel_init(&(panel.panel_info), &panelstruct)) {
dprintf(CRITICAL, "DSI panel init failed!
");
ret = ERROR;
goto error_gcdb_display_init;
}
panel.panel_info.mipi.mdss_dsi_phy_db = &dsi_video_mode_phy_db;
panel.pll_clk_func = mdss_dsi_panel_clock;
panel.power_func = mdss_dsi_panel_power;
panel.pre_init_func = mdss_dsi_panel_pre_init;
panel.bl_func = mdss_dsi_bl_enable;
panel.fb.base = base;
panel.fb.width = panel.panel_info.xres;
panel.fb.height = panel.panel_info.yres;
panel.fb.stride = panel.panel_info.xres;
panel.fb.bpp = panel.panel_info.bpp;
panel.fb.format = panel.panel_info.mipi.dst_format;
} else if (pan_type == PANEL_TYPE_EDP) {
mdss_edp_panel_init(&(panel.panel_info));
/* prepare func is set up at edp_panel_init */
panel.clk_func = mdss_edp_panel_clock;
panel.power_func = mdss_edp_panel_power;
panel.bl_func = mdss_edp_bl_enable;
panel.fb.format = FB_FORMAT_RGB888;
} else {
dprintf(CRITICAL, "Target panel init not found!
");
ret = ERR_NOT_SUPPORTED;
goto error_gcdb_display_init;
}
panel.fb.base = base;
panel.mdp_rev = rev;
ret = msm_display_init(&panel);
error_gcdb_display_init:
display_enable = ret ? 0 : 1;
return ret;
}
根据屏幕的类型，增加panel；如链接所示，可以看到，步骤如下：
2. 在gcdb_display_init()函数中有一个函数oem_panel_select()函数：
（这个函数需要做的工作是：主要是识别不同IC，赋值给参数panel_id，panel_id的使用在同一文件中的 init_panel_data()函数中。）
pan_type = oem_panel_select(panel_name, &panelstruct, &(panel.panel_info), &dsi_video_mode_phy_db);
3. 在oem_panel_select()函数中需要根据你的hw_id来确定使用哪一款的LCD：
panel_override_id = panel_name_to_id(supp_panels, ARRAY_SIZE(supp_panels), panel_name);
supp_panels是struct panel_list，如果要增加一个panel就需要在这里增加一个supp_panels，例如：
static struct panel_list supp_panels[] = {
{"truly_1080p_video", TRULY_1080P_VIDEO_PANEL},
{"truly_1080p_cmd", TRULY_1080P_CMD_PANEL},
{"r69006_1080p_video", R69006_1080P_VIDEO_PANEL},
{"r69006_1080p_cmd", R69006_1080P_CMD_PANEL},
{"truly_wuxga_video", TRULY_WUXGA_VIDEO_PANEL},
{"nt35523_720p_video", NT35523_720P_VIDEO_PANEL},
{"a914_nhd_video", A914_NHD_VIDEO_PANEL}, //这是我们新增的
};
4. 在这个枚举中也需要增加相应的panel：
/*---------------------------------------------------------------------------*/
enum {
TRULY_1080P_VIDEO_PANEL,
TRULY_1080P_CMD_PANEL,
R69006_1080P_VIDEO_PANEL,
R69006_1080P_CMD_PANEL,
TRULY_WUXGA_VIDEO_PANEL,
NT35523_720P_VIDEO_PANEL,
A914_NHD_VIDEO_PANEL, //这是我们新增的
UNKNOWN_PANEL
};
继续向下看：
if (panel_name) {
panel_override_id = panel_name_to_id(supp_panels, ARRAY_SIZE(supp_panels), panel_name);
if (panel_override_id < 0) {
dprintf(CRITICAL, "Not able to search the panel:%s
",
panel_name + strspn(panel_name, " "));
} else if (panel_override_id < UNKNOWN_PANEL) {
/* panel override using fastboot oem command */
panel_id = panel_override_id;
dprintf(INFO, "OEM panel override:%s
",
panel_name + strspn(panel_name, " "));
goto panel_init;
}
}
……
panel_init:
/*
* Update all data structures after 'panel_init' label. Only panel
* selection is supposed to happen before that.
*/
pinfo->pipe_type = MDSS_MDP_PIPE_TYPE_RGB;
return init_panel_data(panelstruct, pinfo, phy_db);
确保能直接跳到panel_init函数中来；
5. 来到init_panel_data()函数中来：
在这里也需要增加一个panel：（当然了，要增加相应的头文件）
#include "include/panel_a914_nhd_video.h"，在target/msm8909/oem_panel.c中增加在这个头文件；
（LCM供应商给的上电顺序，一般来说都要自己根据上电初始化代码来参照）
case TRULY_WUXGA_VIDEO_PANEL:
panelstruct->paneldata = &truly_wuxga_video_panel_data;
panelstruct->paneldata->panel_with_enable_gpio = 1;
panelstruct->panelres = &truly_wuxga_video_panel_res;
panelstruct->color = &truly_wuxga_video_color;
panelstruct->videopanel = &truly_wuxga_video_video_panel;
panelstruct->commandpanel = &truly_wuxga_video_command_panel;
panelstruct->state = &truly_wuxga_video_state;
panelstruct->laneconfig = &truly_wuxga_video_lane_config;
panelstruct->paneltiminginfo = &truly_wuxga_video_timing_info;
panelstruct->panelresetseq = &truly_wuxga_video_panel_reset_seq;
panelstruct->backlightinfo = &truly_wuxga_video_backlight;
pinfo->mipi.panel_on_cmds= truly_wuxga_video_on_command;
pinfo->mipi.num_of_panel_on_cmds= TRULY_WUXGA_VIDEO_ON_COMMAND;
pinfo->mipi.panel_off_cmds= truly_wuxga_video_off_command;
pinfo->mipi.num_of_panel_off_cmds= TRULY_WUXGA_VIDEO_OFF_COMMAND;
memcpy(phy_db->timing, truly_wuxga_14nm_video_timings, MAX_TIMING_CONFIG * sizeof(uint32_t));
pinfo->dfps.panel_dfps = truly_wuxga_video_dfps;
pinfo->mipi.signature = TRULY_WUXGA_VIDEO_SIGNATURE;
break;
/*下面这段代码是我们增加的*/
case A914_NHD_VIDEO_PANEL:
panelstruct->paneldata = &a914_nhd_video_panel_data;
panelstruct->panelres = &a914_nhd_video_panel_res;
panelstruct->color = &a914_nhd_video_color;
panelstruct->videopanel = &a914_nhd_video_video_panel;
panelstruct->commandpanel = &a914_nhd_video_command_panel;
panelstruct->state = &a914_nhd_video_state;
panelstruct->laneconfig = &a914_nhd_video_lane_config;
panelstruct->paneltiminginfo = &a914_nhd_video_timing_info;
panelstruct->panelresetseq = &a914_nhd_video_panel_reset_seq;
panelstruct->backlightinfo = &a914_nhd_video_backlight;
pinfo->mipi.panel_on_cmds = a914_nhd_video_on_command;
pinfo->mipi.num_of_panel_on_cmds = A914_NHD_VIDEO_ON_COMMAND;
pinfo->mipi.panel_off_cmds = a914_nhd_video_off_command;
pinfo->mipi.num_of_panel_off_cmds = A914_NHD_VIDEO_OFF_COMMAND;
memcpy(phy_db->timing,a914_nhd_video_timings, MAX_TIMING_CONFIG * sizeof(uint32_t));
pinfo->mipi.signature = A914_NHD_VIDEO_SIGNATURE;
break;
我们上面分析了这个函数里面的内容，并为其增加了一个panel：
pan_type = oem_panel_select(panel_name, &panelstruct, &(panel.panel_info), &dsi_video_mode_phy_db);
6. 为pan_type也增加一个SPI类型：
else if (pan_type == PANEL_TYPE_SPI ) {
panel.panel_info.xres = panelstruct.panelres->panel_width;
panel.panel_info.yres = panelstruct.panelres->panel_height;
panel.panel_info.bpp = panelstruct.color->color_format;
panel.power_func = mdss_spi_panel_power;
panel.bl_func = mdss_spi_bl_enable;
panel.fb.base = base;
panel.fb.width = panel.panel_info.xres;
panel.fb.height = panel.panel_info.yres;
panel.fb.bpp = panel.panel_info.bpp;
panel.fb.format = FB_FORMAT_RGB888;
panel.panel_info.type = SPI_PANEL;
}
else {
dprintf(CRITICAL, "Target panel init not found!
");
ret = ERR_NOT_SUPPORTED;
goto error_gcdb_display_init;
}
我们增加了mdss_spi_panel_power、mdss_spi_bl_enable函数如下所示：
static int mdss_spi_panel_power(uint8_t enable,
struct msm_panel_info *pinfo)
{
int ret = NO_ERROR;
if (enable) {
ret = target_ldo_ctrl(enable, pinfo);
if (ret) {
dprintf(CRITICAL, "LDO control enable failed
");
return ret;
}
/* Panel Reset */
ret = target_panel_reset(enable, panelstruct.panelresetseq,
&panel.panel_info);
if (ret) {
dprintf(CRITICAL, "panel reset failed
");
return ret;
}
dprintf(INFO, "Panel power on done
");
} else {
/* Disable panel and ldo */
ret = target_panel_reset(enable, panelstruct.panelresetseq,
&panel.panel_info);
if (ret) {
dprintf(CRITICAL, "panel reset disable failed
");
return ret;
}
ret = target_ldo_ctrl(enable, pinfo);
if (ret) {
dprintf(CRITICAL, "ldo control disable failed
");
return ret;
}
dprintf(INFO, "Panel power off done
");
}
return ret;
}
打开显示面板，必须在mdss_dsi_panel_reset前有相应供电，而关闭则相反；
static int mdss_spi_bl_enable(uint8_t enable)
{
int ret = NO_ERROR;
mdelay(100);
ret = panel_backlight_ctrl(enable);
if (ret)
dprintf(CRITICAL, "Backlight %s failed
", enable ? "enable" : "disable");
return ret;
}
7. 来到msm_display_init函数中来，配置spi 的相应管脚：
在上提到的函数中：
int msm_display_init(struct msm_fb_panel_data *pdata)
{
int ret = NO_ERROR;
panel = pdata;
if (!panel) {
ret = ERR_INVALID_ARGS;
goto msm_display_init_out;
}
/* Turn on panel */
if (pdata->power_func)
ret = pdata->power_func(1, &(panel->panel_info)); //执行turn on的函数
if (ret)
goto msm_display_init_out;
/* Enable clock */
if (pdata->clk_func)
ret = pdata->clk_func(1); // //执行配置时钟的函数
/* Only enabled for auto PLL calculation */
if (pdata->pll_clk_func)
ret = pdata->pll_clk_func(1, &(panel->panel_info));
if (ret)
goto msm_display_init_out;
/* pinfo prepare */
if (pdata->panel_info.prepare) {
/* this is for edp which pinfo derived from edid */
ret = pdata->panel_info.prepare();
panel->fb.width = panel->panel_info.xres;
panel->fb.height = panel->panel_info.yres;
panel->fb.stride = panel->panel_info.xres;
panel->fb.bpp = panel->panel_info.bpp;
}
if (ret)
goto msm_display_init_out;
ret = msm_fb_alloc(&(panel->fb));
if (ret)
goto msm_display_init_out;
ret = msm_display_config();
if (ret)
goto msm_display_init_out;
fbcon_setup(&(panel->fb));
display_image_on_screen();
ret = msm_display_on();
if (ret)
goto msm_display_init_out;
if (pdata->post_power_func)
ret = pdata->post_power_func(1);
if (ret)
goto msm_display_init_out;
/* Turn on backlight */
if (pdata->bl_func)
ret = pdata->bl_func(1);
if (ret)
goto msm_display_init_out;
msm_display_init_out:
return ret;
}
其中msm_fb_alloc函数是分配framebuffer空间；
下面我们来分析display_image_on_screen();函数：
void display_image_on_screen(void)
{
#if DISPLAY_TYPE_MIPI
int fetch_image_from_partition();
if (fetch_image_from_partition() < 0) {
display_default_image_on_screen();
} else {
/* data has been put into the right place */
fbcon_flush();
}
#else
display_default_image_on_screen();
#endif
}
由于我们的已经改为SPI方式传送，不是MIPI；所以会直接进入display_default_image_on_screen();函数；
void display_default_image_on_screen(void)
{
unsigned i = 0;
unsigned total_x;
unsigned total_y;
unsigned bytes_per_bpp;
unsigned image_base;
dprintf("CRITICAL", "linhao display_default_image_on_screen
");
if (!config) {
dprintf(CRITICAL,"NULL configuration, image cannot be displayed
");
return;
}
fbcon_clear(); // clear screen with Black color
total_x = config->width;
total_y = config->height;
bytes_per_bpp = ((config->bpp) / 8);
image_base = ((((total_y/2) - (SPLASH_IMAGE_HEIGHT / 2) - 1) *
(config->width)) + (total_x/2 - (SPLASH_IMAGE_WIDTH / 2)));
//24 bit bpp
if (bytes_per_bpp == 3) {
for (i = 0; i < SPLASH_IMAGE_HEIGHT; i++) {
memcpy (config->base + ((image_base + (i * (config->width))) * bytes_per_bpp),
imageBuffer_rgb888 + (i * SPLASH_IMAGE_WIDTH * bytes_per_bpp),
SPLASH_IMAGE_WIDTH * bytes_per_bpp);
}
}
fbcon_flush();
#if DISPLAY_MIPI_PANEL_NOVATEK_BLUE
if(is_cmd_mode_enabled())
mipi_dsi_cmd_mode_trigger();
#endif
//16 bit bpp
if (bytes_per_bpp == 2) {
for (i = 0; i < SPLASH_IMAGE_HEIGHT; i++) {
memcpy (config->base + ((image_base + (i * (config->width))) * bytes_per_bpp),
imageBuffer + (i * SPLASH_IMAGE_WIDTH * bytes_per_bpp),
SPLASH_IMAGE_WIDTH * bytes_per_bpp);
}
}
fbcon_flush();
}
在这里由于没有mipi，所以去掉了#if DISPLAY_TYPE_MIPI宏定义，然后根据24bit真彩色和16bit颜色深度进行相应处理；
最后使用fbcon_flush刷新framebuffer缓冲区；
这样就可以显示默认图片了~~;
display_image_on_screen函数分析完毕之后，继续回到我们的函数msm_display_init函数当中来：
下一步分析msm_display_config函数中来：
int msm_display_config()
{
int ret = NO_ERROR;
int mdp_rev;
struct msm_panel_info *pinfo;
if (!panel)
return ERR_INVALID_ARGS;
pinfo = &(panel->panel_info);
/* Set MDP revision */
mdp_set_revision(panel->mdp_rev);
switch (pinfo->type) {
case LVDS_PANEL:
dprintf(INFO, "Config LVDS_PANEL.
");
ret = mdp_lcdc_config(pinfo, &(panel->fb));
if (ret)
goto msm_display_config_out;
break;
case MIPI_VIDEO_PANEL:
dprintf(INFO, "Config MIPI_VIDEO_PANEL.
");
mdp_rev = mdp_get_revision();
if (mdp_rev == MDP_REV_50 || mdp_rev == MDP_REV_304 ||
mdp_rev == MDP_REV_305)
ret = mdss_dsi_config(panel);
else
ret = mipi_config(panel);
if (ret)
goto msm_display_config_out;
if (pinfo->early_config)
ret = pinfo->early_config((void *)pinfo);
ret = mdp_dsi_video_config(pinfo, &(panel->fb));
if (ret)
goto msm_display_config_out;
break;
case MIPI_CMD_PANEL:
dprintf(INFO, "Config MIPI_CMD_PANEL.
");
mdp_rev = mdp_get_revision();
if (mdp_rev == MDP_REV_50 || mdp_rev == MDP_REV_304 ||
mdp_rev == MDP_REV_305)
ret = mdss_dsi_config(panel);
else
ret = mipi_config(panel);
if (ret)
goto msm_display_config_out;
ret = mdp_dsi_cmd_config(pinfo, &(panel->fb));
if (ret)
goto msm_display_config_out;
break;
case LCDC_PANEL:
dprintf(INFO, "Config LCDC PANEL.
");
ret = mdp_lcdc_config(pinfo, &(panel->fb));
if (ret)
goto msm_display_config_out;
break;
//added by linhao
case SPI_PANEL:
dprintf(INFO, "Config SPI PANEL.
");
ret = mdss_spi_panel_init(pinfo);
if (ret)
goto msm_display_config_out;
break;
case HDMI_PANEL:
dprintf(INFO, "Config HDMI PANEL.
");
ret = mdss_hdmi_config(pinfo, &(panel->fb));
if (ret)
goto msm_display_config_out;
break;
case EDP_PANEL:
dprintf(INFO, "Config EDP PANEL.
");
ret = mdp_edp_config(pinfo, &(panel->fb));
if (ret)
goto msm_display_config_out;
break;
default:
return ERR_INVALID_ARGS;
};
if (pinfo->config)
ret = pinfo->config((void *)pinfo);
msm_display_config_out:
return ret;
}
在SPI_PANEL中进入了mdss_spi_panel_init函数中来：
int mdss_spi_panel_init(struct msm_panel_info *pinfo)
{
int cmd_count = 0;
int ret = 0;
if(!dev) {
//传入参数为SPI_BLSP_ID_1，SPI_QUP_ID_5
dev = qup_blsp_spi_init(SPI_BLSP_ID_1, SPI_QUP_ID_5);
if (!dev) {
dprintf(CRITICAL, "Failed initializing SPI
");
return -ENODEV;
}
}
gpio_tlmm_config(dc_gpio.pin_id, 0,
dc_gpio.pin_direction, dc_gpio.pin_pull,
dc_gpio.pin_strength, dc_gpio.pin_state);
while (cmd_count < pinfo->spi.num_of_panel_cmds) {
mdss_spi_write_cmd(pinfo->spi.panel_cmds[cmd_count].payload);
if (pinfo->spi.panel_cmds[cmd_count].size > 1)
mdss_spi_write_data(pinfo->spi.panel_cmds[cmd_count].payload + 1,
pinfo->spi.panel_cmds[cmd_count].size - 1);
if (pinfo->spi.panel_cmds[cmd_count].wait)
mdelay(pinfo->spi.panel_cmds[cmd_count].wait);
cmd_count ++;
}
return 0;
}
这个函数在lk/platform/msm_shared/mdss_spi.c中，如有需要，则添加这个文件即可；（Android7.0中没有这个文件，之后需要的话，使用patch来补充）
首先增加qup_blsp_spi_init函数，这个函数的作用是配置高通的blsp，高通msm8909的有12个blsp，每一个BLSP含有两个QUP, 每一个QUP可以被配置为I2C， SPI, UART, UIM接口， BLSP是高通对于低速接口的一种管理方式。参考文档为80_NU767_1_H_Linux BAM Low-Speed Peripherals Configuration and Debug Guide.pdf，该文档适用类型为MSM8996, MSM8994,
MSM8992, MSM8952, MSM8916, MSM8936/ MSM8939, MSM8909, MDM9x35, and
MDM9x40/MDM9x45 chipsets.：
struct qup_spi_dev *qup_blsp_spi_init(uint8_t blsp_id, uint8_t qup_id)
{
struct qup_spi_dev *dev;
dev = malloc(sizeof(struct qup_spi_dev));
if (!dev) {
return NULL;
}
dev = memset(dev, 0, sizeof(struct qup_spi_dev));
/* Platform uses BLSP */
dev->qup_irq = BLSP_QUP_IRQ(blsp_id, qup_id);
dev->qup_base = BLSP_QUP_BASE(blsp_id, qup_id);
/* Initialize the GPIO for BLSP spi */
gpio_config_blsp_spi(blsp_id, qup_id);
clock_config_blsp_spi(blsp_id, qup_id);
qup_spi_sec_init(dev);
return dev;
}
对着文档中的表来看：
因为我们选择的是BLSP1（一般为BLSP1），所以QUP_BASE_ADDRESS 为0x78B5000；我们选择的是qup5，所以根据下面公式来计算：
QUP_BASE_ADDRESS的计算公式为:
#define PERIPH_SS_BASE 0x07800000
#define BLSP_QUP_BASE(blsp_id, qup_id) (PERIPH_SS_BASE + 0xB5000 + 0x1000 * qup_id)
根据硬件，进入QUP_ID_5，配置spi的管脚：
void gpio_config_blsp_spi(uint8_t blsp_id, uint8_t qup_id)
{
if(blsp_id == BLSP_ID_1) {
switch (qup_id) {
case QUP_ID_4:
/* configure SPI MOSI gpio */
gpio_tlmm_config(16, 1, GPIO_OUTPUT, GPIO_NO_PULL,
GPIO_16MA, GPIO_DISABLE);
/* configure SPI MISO gpio */
gpio_tlmm_config(17, 1, GPIO_OUTPUT, GPIO_NO_PULL,
GPIO_16MA, GPIO_DISABLE);
/* configure SPI CS_N gpio */
gpio_tlmm_config(18, 1, GPIO_OUTPUT, GPIO_NO_PULL,
GPIO_16MA, GPIO_DISABLE);
/* configure SPI CLK gpio */
gpio_tlmm_config(19, 1, GPIO_OUTPUT, GPIO_NO_PULL,
GPIO_16MA, GPIO_DISABLE);
break;
case QUP_ID_0:
break;
case QUP_ID_1:
break;
case QUP_ID_2:
break;
case QUP_ID_3:
break;
case QUP_ID_5:
/* configure SPI MOSI gpio */
gpio_tlmm_config(8, 1, GPIO_OUTPUT, GPIO_NO_PULL,
GPIO_16MA, GPIO_DISABLE);
/* configure SPI MISO gpio */
gpio_tlmm_config(9, 1, GPIO_OUTPUT, GPIO_NO_PULL,
GPIO_16MA, GPIO_DISABLE);
/* configure SPI CS_N gpio */
gpio_tlmm_config(10, 1, GPIO_OUTPUT, GPIO_NO_PULL,
GPIO_16MA, GPIO_DISABLE);
/* configure SPI CLK gpio */
gpio_tlmm_config(11, 1, GPIO_OUTPUT, GPIO_NO_PULL,
GPIO_16MA, GPIO_DISABLE);
break;
default:
dprintf(CRITICAL, "Incorrect QUP id %d
",qup_id);
ASSERT(0);
};
} else {
dprintf(CRITICAL, "Incorrect BLSP id %d
",blsp_id);
ASSERT(0);
}
}
继续向下看，配置spi时钟：
/* Configure spi clock */
void clock_config_blsp_spi(uint8_t blsp_id, uint8_t qup_id)
{
uint8_t ret = 0;
char clk_name[64];
struct clk *qup_clk;
if((blsp_id != BLSP_ID_1)) {
dprintf(CRITICAL, "Incorrect BLSP-%d configuration
", blsp_id);
ASSERT(0);
}
snprintf(clk_name, sizeof(clk_name), "blsp1_ahb_iface_clk");
ret = clk_get_set_enable(clk_name, 0 , 1);
if (ret) {
dprintf(CRITICAL, "%s: Failed to enable %s clock
", __func__, clk_name);
return;
}
snprintf(clk_name, sizeof(clk_name), "gcc_blsp1_qup%u_spi_apps_clk", qup_id + 1);
/* Set the highest clk frequency by default for good performance. */
ret = clk_get_set_enable(clk_name, 50000000, 1);
if (ret) {
dprintf(CRITICAL, "%s: Failed to enable %s
", __func__, clk_name);
return;
}
}
接下来看qup_spi_sec_init(dev);
这里都是寄存器配置的东西，直接看patch就行了；
至此：msm_display_config()函数分析完毕；
我们接下来分析msm_display_on函数：
int msm_display_on()
{
int ret = NO_ERROR;
int mdp_rev;
struct msm_panel_info *pinfo;
if (!panel)
return ERR_INVALID_ARGS;
bs_set_timestamp(BS_SPLASH_SCREEN_DISPLAY);
pinfo = &(panel->panel_info);
if (pinfo->pre_on) {
ret = pinfo->pre_on();
if (ret)
goto msm_display_on_out;
}
switch (pinfo->type) {
case LVDS_PANEL:
dprintf(INFO, "Turn on LVDS PANEL.
");
ret = mdp_lcdc_on(panel);
if (ret)
goto msm_display_on_out;
ret = lvds_on(panel);
if (ret)
goto msm_display_on_out;
break;
case MIPI_VIDEO_PANEL:
dprintf(INFO, "Turn on MIPI_VIDEO_PANEL.
");
ret = mdp_dsi_video_on(pinfo);
if (ret)
goto msm_display_on_out;
ret = mdss_dsi_post_on(panel);
if (ret)
goto msm_display_on_out;
ret = mipi_dsi_on();
if (ret)
goto msm_display_on_out;
break;
case MIPI_CMD_PANEL:
dprintf(INFO, "Turn on MIPI_CMD_PANEL.
");
ret = mdp_dma_on(pinfo);
if (ret)
goto msm_display_on_out;
mdp_rev = mdp_get_revision();
if (mdp_rev != MDP_REV_50 && mdp_rev != MDP_REV_304 &&
mdp_rev != MDP_REV_305) {
ret = mipi_cmd_trigger();
if (ret)
goto msm_display_on_out;
}
ret = mdss_dsi_post_on(panel);
if (ret)
goto msm_display_on_out;
break;
case LCDC_PANEL:
dprintf(INFO, "Turn on LCDC PANEL.
");
ret = mdp_lcdc_on(panel);
if (ret)
goto msm_display_on_out;
break;
case HDMI_PANEL:
dprintf(INFO, "Turn on HDMI PANEL.
");
ret = mdss_hdmi_init();
if (ret)
goto msm_display_on_out;
ret = mdss_hdmi_on();
if (ret)
goto msm_display_on_out;
break;
case EDP_PANEL:
dprintf(INFO, "Turn on EDP PANEL.
");
ret = mdp_edp_on(pinfo);
if (ret)
goto msm_display_on_out;
break;
//added by linhao,support spi
case SPI_PANEL:
dprintf(INFO, "Turn on SPI PANEL.
");
ret = mdss_spi_on(pinfo, &(panel->fb));
if (ret)
goto msm_display_on_out;
break;
default:
return ERR_INVALID_ARGS;
};
if (pinfo->on)
ret = pinfo->on();
msm_display_on_out:
return ret;
}
接下来就继续执行这两个函数了：
if (pdata->post_power_func)
ret = pdata->post_power_func(1);
if (ret)
goto msm_display_init_out;
/* Turn on backlight */
if (pdata->bl_func)
ret = pdata->bl_func(1);
看它们的函数指针内容：
第一个函数mdss_spi_panel_power，这个函数实现了:
static int mdss_spi_panel_power(uint8_t enable,
struct msm_panel_info *pinfo)
{
int ret = NO_ERROR;
if (enable) {
ret = target_ldo_ctrl(enable, pinfo);
if (ret) {
dprintf(CRITICAL, "LDO control enable failed
");
return ret;
}
/* Panel Reset */
ret = target_panel_reset(enable, panelstruct.panelresetseq,
&panel.panel_info);
if (ret) {
dprintf(CRITICAL, "panel reset failed
");
return ret;
}
dprintf(INFO, "Panel power on done
");
} else {
/* Disable panel and ldo */
ret = target_panel_reset(enable, panelstruct.panelresetseq,
&panel.panel_info);
if (ret) {
dprintf(CRITICAL, "panel reset disable failed
");
return ret;
}
ret = target_ldo_ctrl(enable, pinfo);
if (ret) {
dprintf(CRITICAL, "ldo control disable failed
");
return ret;
}
dprintf(INFO, "Panel power off done
");
}
return ret;
}
看其中的target_ldo_ctrl函数，这个函数是控制电源的：
int target_ldo_ctrl(uint8_t enable, struct msm_panel_info *pinfo)
{
if (enable){
if (pinfo->type == SPI_PANEL)
spi_panel_regulator_enable(); /* L6, and L17 */
else
regulator_enable(); /* L2, L6, and L17 */
}
return NO_ERROR;
}
由于pinfo->type == SPI_PANEL进入了spi_panel_regulator_enable函数中来，根据电路图，需要使能L6、L17：
void spi_panel_regulator_enable()
{
rpm_send_data(&ldo17[GENERIC_ENABLE][0], 36, RPM_REQUEST_TYPE);
rpm_send_data(&ldo6[GENERIC_ENABLE][0], 36, RPM_REQUEST_TYPE);
}
然后使用target_panel_reset函数对面板进行重置；
至此电源已经完成；
背光函数mdss_spi_bl_enable->panel_backlight_ctrl->target_backlight_ctrl函数中：
通过pwm或者WLED方式控制背光，不支持BL_DCS：
if (bl->bl_interface_type == BL_DCS)
return 0;
终于，msm_display_init函数已经分析完毕，随之gcdb_display_init也分析完毕；target_display_init也分析完了；