C++ clk_register_fixed_rate函数代码示例

void __init vexpress_clk_init(void __iomem *sp810_base)
{
    struct clk *clk;
    int i;

    clk = clk_register_fixed_rate(NULL, "dummy_apb_pclk", NULL,
                                  CLK_IS_ROOT, 0);
    WARN_ON(clk_register_clkdev(clk, "apb_pclk", NULL));

    clk = clk_register_fixed_rate(NULL, "v2m:clk_24mhz", NULL,
                                  CLK_IS_ROOT, 24000000);
    for (i = 0; i < ARRAY_SIZE(vexpress_clk_24mhz_periphs); i++)
        WARN_ON(clk_register_clkdev(clk, NULL,
                                    vexpress_clk_24mhz_periphs[i]));

    clk = clk_register_fixed_rate(NULL, "v2m:refclk32khz", NULL,
                                  CLK_IS_ROOT, 32768);
    WARN_ON(clk_register_clkdev(clk, NULL, "v2m:wdt"));

    clk = clk_register_fixed_rate(NULL, "v2m:refclk1mhz", NULL,
                                  CLK_IS_ROOT, 1000000);

    vexpress_sp810_init(sp810_base);

    for (i = 0; i < ARRAY_SIZE(vexpress_sp810_timerclken); i++)
        WARN_ON(clk_set_parent(vexpress_sp810_timerclken[i], clk));

    WARN_ON(clk_register_clkdev(vexpress_sp810_timerclken[0],
                                "v2m-timer0", "sp804"));
    WARN_ON(clk_register_clkdev(vexpress_sp810_timerclken[1],
                                "v2m-timer1", "sp804"));
}

static void __init atlas6_clk_init(struct device_node *np)
{
	struct device_node *rscnp;
	int i;

	rscnp = of_find_compatible_node(NULL, NULL, "sirf,prima2-rsc");
	sirfsoc_rsc_vbase = of_iomap(rscnp, 0);
	if (!sirfsoc_rsc_vbase)
		panic("unable to map rsc registers\n");
	of_node_put(rscnp);

	sirfsoc_clk_vbase = of_iomap(np, 0);
	if (!sirfsoc_clk_vbase)
		panic("unable to map clkc registers\n");

	/* These are always available (RTC and 26MHz OSC)*/
	atlas6_clks[rtc] = clk_register_fixed_rate(NULL, "rtc", NULL,
		CLK_IS_ROOT, 32768);
	atlas6_clks[osc] = clk_register_fixed_rate(NULL, "osc", NULL,
		CLK_IS_ROOT, 26000000);

	for (i = pll1; i < maxclk; i++) {
		atlas6_clks[i] = clk_register(NULL, atlas6_clk_hw_array[i]);
		BUG_ON(!atlas6_clks[i]);
	}
	clk_register_clkdev(atlas6_clks[cpu], NULL, "cpu");
	clk_register_clkdev(atlas6_clks[io],  NULL, "io");
	clk_register_clkdev(atlas6_clks[mem],  NULL, "mem");
	clk_register_clkdev(atlas6_clks[mem],  NULL, "osc");

	clk_data.clks = atlas6_clks;
	clk_data.clk_num = maxclk;

	of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data);
}

static void __init v2m_clk_init(void)
{
	struct clk *clk;
	int i;

	clk = clk_register_fixed_rate(NULL, "dummy_apb_pclk", NULL,
			CLK_IS_ROOT, 0);
	WARN_ON(clk_register_clkdev(clk, "apb_pclk", NULL));

	clk = clk_register_fixed_rate(NULL, "mb:ref_clk", NULL,
			CLK_IS_ROOT, 32768);
	for (i = 0; i < ARRAY_SIZE(v2m_ref_clk_periphs); i++)
		WARN_ON(clk_register_clkdev(clk, NULL, v2m_ref_clk_periphs[i]));

	clk = clk_register_fixed_rate(NULL, "mb:sp804_clk", NULL,
			CLK_IS_ROOT, 1000000);
	WARN_ON(clk_register_clkdev(clk, "v2m-timer0", "sp804"));
	WARN_ON(clk_register_clkdev(clk, "v2m-timer1", "sp804"));

	clk = v2m_osc_register("mb:osc1", &v2m_mb_osc1);
	for (i = 0; i < ARRAY_SIZE(v2m_osc1_periphs); i++)
		WARN_ON(clk_register_clkdev(clk, NULL, v2m_osc1_periphs[i]));

	clk = clk_register_fixed_rate(NULL, "mb:osc2", NULL,
			CLK_IS_ROOT, 24000000);
	for (i = 0; i < ARRAY_SIZE(v2m_osc2_periphs); i++)
		WARN_ON(clk_register_clkdev(clk, NULL, v2m_osc2_periphs[i]));
}

/*
 * These are fixed clocks. They're probably not all root clocks and it may
 * be possible to turn them on and off but until this is mapped out better
 * it's the only way they can be used.
 */
void __init bcm2835_init_clocks(void)
{
	struct clk *clk;
	int ret;

	clk = clk_register_fixed_rate(NULL, "apb_pclk", NULL, CLK_IS_ROOT,
					126000000);
	if (IS_ERR(clk))
		pr_err("apb_pclk not registered\n");

	clk = clk_register_fixed_rate(NULL, "uart0_pclk", NULL, CLK_IS_ROOT,
					3000000);
	if (IS_ERR(clk))
		pr_err("uart0_pclk not registered\n");
	ret = clk_register_clkdev(clk, NULL, "20201000.uart");
	if (ret)
		pr_err("uart0_pclk alias not registered\n");

	clk = clk_register_fixed_rate(NULL, "uart1_pclk", NULL, CLK_IS_ROOT,
					125000000);
	if (IS_ERR(clk))
		pr_err("uart1_pclk not registered\n");
	ret = clk_register_clkdev(clk, NULL, "20215000.uart");
	if (ret)
		pr_err("uart1_pclk alias not registered\n");
}

void __init mvebu_coreclk_setup(struct device_node *np,
				const struct coreclk_soc_desc *desc)
{
	const char *tclk_name = "tclk";
	const char *cpuclk_name = "cpuclk";
	void __iomem *base;
	unsigned long rate;
	int n;

	base = of_iomap(np, 0);
	if (WARN_ON(!base))
		return;

	/* Allocate struct for TCLK, cpu clk, and core ratio clocks */
	clk_data.clk_num = 2 + desc->num_ratios;
	clk_data.clks = kzalloc(clk_data.clk_num * sizeof(struct clk *),
				GFP_KERNEL);
	if (WARN_ON(!clk_data.clks)) {
		iounmap(base);
		return;
	}

	/* Register TCLK */
	of_property_read_string_index(np, "clock-output-names", 0,
				      &tclk_name);
	rate = desc->get_tclk_freq(base);
	clk_data.clks[0] = clk_register_fixed_rate(NULL, tclk_name, NULL,
						   CLK_IS_ROOT, rate);
	WARN_ON(IS_ERR(clk_data.clks[0]));

	/* Register CPU clock */
	of_property_read_string_index(np, "clock-output-names", 1,
				      &cpuclk_name);
	rate = desc->get_cpu_freq(base);
	clk_data.clks[1] = clk_register_fixed_rate(NULL, cpuclk_name, NULL,
						   CLK_IS_ROOT, rate);
	WARN_ON(IS_ERR(clk_data.clks[1]));

	/* Register fixed-factor clocks derived from CPU clock */
	for (n = 0; n < desc->num_ratios; n++) {
		const char *rclk_name = desc->ratios[n].name;
		int mult, div;

		of_property_read_string_index(np, "clock-output-names",
					      2+n, &rclk_name);
		desc->get_clk_ratio(base, desc->ratios[n].id, &mult, &div);
		clk_data.clks[2+n] = clk_register_fixed_factor(NULL, rclk_name,
				       cpuclk_name, 0, mult, div);
		WARN_ON(IS_ERR(clk_data.clks[2+n]));
	};

	/* SAR register isn't needed anymore */
	iounmap(base);

	of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data);
}

/*
 * realview_clk_init() - set up the RealView clock tree
 */
void __init realview_clk_init(void *sysbase, bool is_pb1176)
{
	struct clk *clk;

	/* APB clock dummy */
	clk = clk_register_fixed_rate(NULL, "apb_pclk", NULL, CLK_IS_ROOT, 0);
	clk_register_clkdev(clk, "apb_pclk", NULL);

	/* 24 MHz clock */
	clk = clk_register_fixed_rate(NULL, "clk24mhz", NULL, CLK_IS_ROOT,
				24000000);
	clk_register_clkdev(clk, NULL, "dev:uart0");
	clk_register_clkdev(clk, NULL, "dev:uart1");
	clk_register_clkdev(clk, NULL, "dev:uart2");
	clk_register_clkdev(clk, NULL, "fpga:kmi0");
	clk_register_clkdev(clk, NULL, "fpga:kmi1");
	clk_register_clkdev(clk, NULL, "fpga:mmc0");
	clk_register_clkdev(clk, NULL, "dev:ssp0");
	if (is_pb1176) {
		/*
		 * UART3 is on the dev chip in PB1176
		 * UART4 only exists in PB1176
		 */
		clk_register_clkdev(clk, NULL, "dev:uart3");
		clk_register_clkdev(clk, NULL, "dev:uart4");
	} else
		clk_register_clkdev(clk, NULL, "fpga:uart3");

	/* FIXME: Dummy clocks to force match with device tree node names */
	clk_register_clkdev(clk, NULL, "kmi0");
	clk_register_clkdev(clk, NULL, "kmi1");

	/* 1 MHz clock */
	clk = clk_register_fixed_rate(NULL, "clk1mhz", NULL, CLK_IS_ROOT,
				      1000000);
	clk_register_clkdev(clk, NULL, "sp804");

	/* ICST VCO clock */
	if (is_pb1176)
		clk = icst_clk_register(NULL, &realview_osc0_desc, sysbase);
	else
		clk = icst_clk_register(NULL, &realview_osc4_desc, sysbase);

	clk_register_clkdev(clk, NULL, "dev:clcd");
	clk_register_clkdev(clk, NULL, "issp:clcd");

	/* FIXME: Dummy clocks to force match with device tree node names */
	clk_register_clkdev(clk, NULL, "clcd");
}

int hisi_clk_register_fixed_rate(const struct hisi_fixed_rate_clock *clks,
					 int nums, struct hisi_clock_data *data)
{
	struct clk *clk;
	int i;

	for (i = 0; i < nums; i++) {
		clk = clk_register_fixed_rate(NULL, clks[i].name,
					      clks[i].parent_name,
					      clks[i].flags,
					      clks[i].fixed_rate);
		if (IS_ERR(clk)) {
			pr_err("%s: failed to register clock %s\n",
			       __func__, clks[i].name);
			goto err;
		}
		data->clk_data.clks[clks[i].id] = clk;
	}

	return 0;

err:
	while (i--)
		clk_unregister_fixed_rate(data->clk_data.clks[clks[i].id]);

	return PTR_ERR(clk);
}

/**
 * of_fixed_clk_setup() - Setup function for simple fixed rate clock
 */
void of_fixed_clk_setup(struct device_node *node)
{
	struct clk *clk;
	const char *clk_name = node->name;
	u32 rate = 0;

	if (of_property_read_u32(node, "clock-frequency", &rate)) {
		pr_err("%s Fixed rate clock <%s> must have a clock rate property\n",
			__func__, node->name);
		return;
	}

	if (of_property_read_string(node, "clock-output-names", &clk_name)) {
		pr_err("%s Fixed rate clock <%s> must have a clock name property\n",
			__func__, node->name);
		return;
	}

	clk = clk_register_fixed_rate(NULL, clk_name, NULL, CLK_IS_ROOT, rate);
	if (!IS_ERR(clk))
		of_clk_add_provider(node, of_clk_src_simple_get, clk);
#ifdef CONFIG_HI3630_CLK
	clk_register_clkdev(clk, clk_name, NULL);
#endif
}

/*
 * ccu_osc_clk_init
 * ccu is in same PCI device with PMU. CCU address is at offset 0x800.
 * ccu's inialization is called from PMU init.
 */
int ccu_osc_clk_init(void __iomem *ccubase)
{
	struct clk *clk;
	int i, ret;
	char name[12];

	pr_debug("%s entry\n", __func__);

	clk = clk_register_fixed_rate(NULL, "clk-osc", NULL,
			CLK_IS_ROOT, OSC_CLOCK_RATE);
	if (IS_ERR(clk)) {
		pr_err("%s:clk register fail.\n", __func__);
		return -1;
	}
	clk_register_clkdev(clk, "clk-osc", NULL);

	for (i = 0; i < OSC_CLOCK_COUNT; i++) {
		memset(name, 0, sizeof(name));
		sprintf(name, "osc.%d", i);
		clk = ccu_osc_clk_register(name, "clk-osc", ccubase
				+ CCU_OSC_CTL_OFF + i * 4, i);
		if (!IS_ERR(clk))
			ret = clk_register_clkdev(clk, name, NULL);
	}

	return 0;
}

void __init clk_init(void)
{
	tclk = clk_register_fixed_rate(NULL, "tclk", NULL, CLK_IS_ROOT,
				       orion5x_tclk);

	orion_clkdev_init(tclk);
}

static struct clk * __init
meson_clk_register_fixed_rate(const struct clk_conf *clk_conf,
			      void __iomem *clk_base)
{
	struct clk *clk;
	const struct fixed_rate_conf *fixed_rate_conf;
	const struct parm *r;
	unsigned long rate;
	u32 reg;

	fixed_rate_conf = &clk_conf->conf.fixed_rate;
	rate = fixed_rate_conf->rate;

	if (!rate) {
		r = &fixed_rate_conf->rate_parm;
		reg = readl(clk_base + clk_conf->reg_off + r->reg_off);
		rate = PARM_GET(r->width, r->shift, reg);
	}

	rate *= 1000000;

	clk = clk_register_fixed_rate(NULL,
			clk_conf->clk_name,
			clk_conf->num_parents
				? clk_conf->clks_parent[0] : NULL,
			clk_conf->flags, rate);

	return clk;
}

/* register a list of fixed clocks */
void __init amlogic_clk_register_fixed_rate(
		struct amlogic_fixed_rate_clock *list, unsigned int nr_clk)
{
	struct clk *clk;
	unsigned int idx, ret;

	for (idx = 0; idx < nr_clk; idx++, list++) {
		clk = clk_register_fixed_rate(NULL, list->name,
			list->parent_name, list->flags, list->fixed_rate);
		if (IS_ERR(clk)) {
			pr_err("%s: failed to register clock %s\n", __func__,
				list->name);
			continue;
		}

		amlogic_clk_add_lookup(clk, list->id);

		/*
		 * Unconditionally add a clock lookup for the fixed rate clocks.
		 * There are not many of these on any of Amlogic platforms.
		 */
		ret = clk_register_clkdev(clk, list->name, NULL);
		if (ret)
			pr_err("%s: failed to register clock lookup for %s",
				__func__, list->name);
	}
}

static int dw_i2c_acpi_configure(struct platform_device *pdev)
{
	struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
	const struct acpi_device_id *id;

	dev->adapter.nr = -1;
	dev->tx_fifo_depth = 32;
	dev->rx_fifo_depth = 32;

	/*
	 * Try to get SDA hold time and *CNT values from an ACPI method if
	 * it exists for both supported speed modes.
	 */
	dw_i2c_acpi_params(pdev, "SSCN", &dev->ss_hcnt, &dev->ss_lcnt, NULL);
	dw_i2c_acpi_params(pdev, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt,
			   &dev->sda_hold_time);

	/*
	 * Provide a way for Designware I2C host controllers that are not
	 * based on Intel LPSS to specify their input clock frequency via
	 * id->driver_data.
	 */
	id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);
	if (id && id->driver_data)
		clk_register_fixed_rate(&pdev->dev, dev_name(&pdev->dev), NULL,
					CLK_IS_ROOT, id->driver_data);

	return 0;
}

void __init socfpga_init_clocks(void)
{
	struct clk *clk;

	clk = clk_register_fixed_rate(NULL, "osc1_clk", NULL, CLK_IS_ROOT, SOCFPGA_OSC1_CLK);
	clk_register_clkdev(clk, "osc1_clk", NULL);

	clk = clk_register_fixed_rate(NULL, "mpu_clk", NULL, CLK_IS_ROOT, SOCFPGA_MPU_CLK);
	clk_register_clkdev(clk, "mpu_clk", NULL);

	clk = clk_register_fixed_rate(NULL, "main_clk", NULL, CLK_IS_ROOT, SOCFPGA_MPU_CLK/2);
	clk_register_clkdev(clk, "main_clk", NULL);

	clk = clk_register_fixed_rate(NULL, "dbg_base_clk", NULL, CLK_IS_ROOT, SOCFPGA_MPU_CLK/2);
	clk_register_clkdev(clk, "dbg_base_clk", NULL);

	clk = clk_register_fixed_rate(NULL, "main_qspi_clk", NULL, CLK_IS_ROOT, SOCFPGA_MAIN_QSPI_CLK);
	clk_register_clkdev(clk, "main_qspi_clk", NULL);

	clk = clk_register_fixed_rate(NULL, "main_nand_sdmmc_clk", NULL, CLK_IS_ROOT, SOCFPGA_MAIN_NAND_SDMMC_CLK);
	clk_register_clkdev(clk, "main_nand_sdmmc_clk", NULL);

	clk = clk_register_fixed_rate(NULL, "s2f_usr_clk", NULL, CLK_IS_ROOT, SOCFPGA_S2F_USR_CLK);
	clk_register_clkdev(clk, "s2f_usr_clk", NULL);
}

static struct clk *sysclk_from_fixed(struct device_node *node, const char *name)
{
	u32 rate;

	if (of_property_read_u32(node, "clock-frequency", &rate))
		return ERR_PTR(-ENODEV);

	return clk_register_fixed_rate(NULL, name, NULL, CLK_IS_ROOT, rate);
}