高通 SPI驱动笔记

1. 设备树

//msm8909.dtsi:
        spi_1: spi@78b9000 { /* BLSP1 QUP5 */
                compatible = "qcom,spi-qup-v2";//厂商设备名
                #address-cells = <1>;//子元素地址值的个数
                #size-cells = <0>;//子元素长度值的个数
                reg-names = "spi_physical", "spi_bam_physical";
                reg = <0x78b9000 0x600>,//SPI地址
                      <0x7884000 0x23000>;//BAM地址
                interrupt-names = "spi_irq", "spi_bam_irq";
                /*中断号（BLSP4\SWDocument\BSP\Peripherals\BAM，\SWDocument\BSP\Peripherals\BAM）
                BLSP[1~12]->IRQ[95~106]
                BLSP[1~6]->BAM IRQ =238,BLSP[7~12]->BAM IRQ =239
                */
                interrupts = <0 99 0>, <0 238 0>;
                spi-max-frequency = <19200000>;//最大传输波特率
                pinctrl-names = "spi_default", "spi_sleep";
                pinctrl-0 = <&spi1_default &spi1_cs0_active>;
                pinctrl-1 = <&spi1_sleep &spi1_cs0_sleep>;
                clocks = <&clock_gcc clk_gcc_blsp1_ahb_clk>,
                         <&clock_gcc clk_gcc_blsp1_qup5_spi_apps_clk>;
                clock-names = "iface_clk", "core_clk";
                qcom,infinite-mode = <0>;//qup初始模式
                qcom,use-bam;
                qcom,use-pinctrl;
                qcom,ver-reg-exists;
                /*
                bam-consumer-pipe-index:BLSP BAM pipes 见\SWDocument\BSP\Peripherals\BAM Table4-5
                bam-producer-pipe-index:BLSP BAM pipes 见\SWDocument\BSP\Peripherals\BAM Table4-5
                */
                qcom,bam-consumer-pipe-index = <18>;
                qcom,bam-producer-pipe-index = <19>;
                //BLSP bus master ID 见\SWDocument\BSP\Peripherals\BAM Table4-3
                qcom,master-id = <86>;
        };

//msm8909-pinctrl.dtsi:
        spi1_active {
                /* MOSI, MISO, CLK */
                qcom,pins = <&gp 16>, <&gp 17>, <&gp 19>;
                qcom,num-grp-pins = <3>;//how many pins contains in all
                qcom,pin-func = <1>;//function pin
                label = "spi1-active";
                /* active state */
                spi1_default: spi1_default {
                        drive-strength = <12>; /* 12 MA */
                        bias-disable = <0>; /* No PULL */
                };
        };

        spi1_suspend {
                /* MOSI, MISO, CLK */
                qcom,pins = <&gp 16>, <&gp 17>, <&gp 19>;
                qcom,num-grp-pins = <3>;
                qcom,pin-func = <0>;
                label = "spi1-suspend";
                /* suspended state */
                spi1_sleep: spi1_sleep {
                        drive-strength = <2>; /* 2 MA */
                        bias-pull-down; /* pull down */
                };
        };

        spi1_cs0_active {
                /* CS */
                qcom,pins = <&gp 18>;
                qcom,num-grp-pins = <1>;
                qcom,pin-func = <1>;
                label = "spi1-cs0-active";
                spi1_cs0_active: cs0_active {
                        drive-strength = <2>;
                        bias-disable = <0>;
                };
        };


        spi1_cs0_suspend {
                /* CS */
                qcom,pins = <&gp 18>;
                qcom,num-grp-pins = <1>;
                qcom,pin-func = <0>;
                label = "spi1-cs0-suspend";
                spi1_cs0_sleep: cs0_sleep {
                        drive-strength = <2>;
                        bias-disable = <0>;
                };
        };

注意：

    如有GPIO重复使用，请屏蔽相关gpio和相关驱动（如I2C_5，因为I2C和SPI均被注册），
    tpiu_setb_4 中
        //qcom,pins = <&gp 16>;
    tpiu_setb_5 中
        //qcom,pins = <&gp 17>;
    tlmm_gpio_key 中
        //ZHANGLEI
        //qcom,pins = <&gp 16>, <&gp 17>, <&gp 92>; // 90 91

2. set up clocks

//此步骤不适用于msm8994之后的版本

Project_Root/drivers/clk/qcom/clock-gcc-8909.c:
//一部分cpu版本在kernel/arch/arm/mach-msm/下
添加时钟节点：
/* Clock lookup */
static struct clk_lookup msm_clocks_lookup[] = {
//Add node to BLSP1 AHB Clock

CLK_LIST(gcc_blsp1_ahb_clk),

/*
Add a node to QUP Core clock.
*/
CLK_LIST(blsp1_qup4_spi_apps_clk_src),

3. Set up the GPIO

//此步骤不适用于msm8994之后的版本

3.1 Project_Root/kernel/arch/arm/mach-msm/board--gpiomux.c

3.1.1 Create a configuration structure:

static struct gpiomux_setting gpio_blsp1_spi_config

3.1.2 Create a GPIO array：

static struct msm_gpiomux_config msm_blsp_configs[] __initdata

3.1.3 Register the GPIOs:

void __init msm_8974_init_gpiomux(void)

4. Configure the runtime GPIO:

//此步骤不适用于msm8994之后的版本

4.1 Project_Root/kernel/arch/arm/mach-msm/board--gpiomux.c

4.1.1 Create a suspend/active configuration structure:

static struct gpiomux_setting gpio_blsp1_spi_config
static struct gpiomux_setting gpio_blsp1_spi_suspend_config

4.1.2 Create a GPIO array

static struct msm_gpiomux_config msm_blsp_configs[] __initdata

4.1.3 Register the GPIOs

void __init msm_8974_init_gpiomux(void)

4.1.4 Add GPIO numbers to the device tree.

/kernel/arch/arm/boot/dts/-cdp.dts