3-->i.mx287基于linux-2.6.35内核驱动之clk_get()函数用法

原文地址：http://blog.chinaunix.net/uid-27041925-id-3523517.html

clk_get(NULL,"lradc")用来获得lradc时钟，clk_get从一个时钟list链表中以字符id名称来查找一个时钟clk结构体。之后调用clk_enable()，能使能对应的外设时钟源。
clk_get(NULL,"lradc"),函数的第二个参数"lradc"是在内核2.6.35中的arch/arm/mach-mx28/clock.c文件中定义的:

static struct clk_lookup onchip_clocks[] = {
{
.con_id = "xtal.0",
.clk = &xtal_clk[0],
},
{
.con_id = "xtal.1",
.clk = &xtal_clk[1],
},
{
.con_id = "xtal.2",
.clk = &xtal_clk[2],
},
{
.con_id = "pll.0",
.clk = &pll_clk[0],
},
{
.con_id = "pll.1",
.clk = &pll_clk[1],
},
{
.con_id = "pll.2",
.clk = &pll_clk[2],
},
{
.con_id = "ref_xtal",
.clk = &ref_xtal_clk,
},
{
.con_id = "ref_cpu",
.clk = &ref_cpu_clk,
},
{
.con_id = "ref_emi",
.clk = &ref_emi_clk,
},
{
.con_id = "ref_io.0",
.clk = &ref_io_clk[0],
},
{
.con_id = "ref_io.1",
.clk = &ref_io_clk[1],
},
{
.con_id = "ref_pix",
.clk = &ref_pix_clk,
},
{
.con_id = "ref_hsadc",
.clk = &ref_hsadc_clk,
},
{
.con_id = "ref_gpmi",
.clk = &ref_gpmi_clk,
},
{
.con_id = "ana",
.clk = &ana_clk,
},
{
.con_id = "rtc",
.clk = &rtc_clk,
},
{
.con_id = "cpu",
.clk = &cpu_clk,
},
{
.con_id = "h",
.clk = &h_clk,
},
{
.con_id = "x",
.clk = &x_clk,
},
{
.con_id = "ocrom",
.clk = &ocrom_clk,
},
{
.con_id = "clk_32k",
.clk = &clk_32k,
},
{
.con_id = "uart",
.clk = &uart_clk,
},
{
.con_id = "pwm",
.clk = &pwm_clk,
},
{
.con_id = "lradc",
.clk = &lradc_clk,
},
{
.con_id = "ssp.0",
.clk = &ssp_clk[0],
},
{
.con_id = "ssp.1",
.clk = &ssp_clk[1],
},
{
.con_id = "ssp.2",
.clk = &ssp_clk[2],
},
{
.con_id = "ssp.3",
.clk = &ssp_clk[3],
},
{
.con_id = "gpmi",
.clk = &gpmi_clk,
},
{
.con_id = "spdif",
.clk = &pcmspdif_clk,
},
{
.con_id = "saif.0",
.clk = &saif_clk[0],
},
{
.con_id = "saif.1",
.clk = &saif_clk[1],
},
{
.con_id = "emi",
.clk = &emi_clk,
},
{
.con_id = "dis_lcdif",
.clk = &dis_lcdif_clk,
},
{
.con_id = "hsadc",
.clk = &hsadc_clk,
},
{
.con_id = "can_clk",
.dev_id = "FlexCAN.0",
.clk = &flexcan_clk[0],
},
{
.con_id = "can_clk",
.dev_id = "FlexCAN.1",
.clk = &flexcan_clk[1],
},
{
.con_id = "usb_clk0",
.clk = &usb_clk0,
},
{
.con_id = "usb_clk1",
.clk = &usb_clk1,
},
{
.con_id = "usb_phy_clk0",
.clk = &usb_phy_clk0,
},
{
.con_id = "usb_phy_clk1",
.clk = &usb_phy_clk1,
},
{
.con_id = "fec_clk",
.clk = &enet_out_clk,
},
{
.con_id = "saif_mclk.0",
.clk = &saif_mclk[0],
},
{
.con_id = "saif_mclk.1",
.clk = &saif_mclk[1],
}
};