ptp_qoriq: support automatic configuration for ptp timer (91305f28) · Commits · 戴 / test

drivers/ptp/ptp_qoriq.c

+108 −3

Original line number	Diff line number	Diff line
		@@ -29,6 +29,7 @@
		#include <linux/of_platform.h>
		#include <linux/timex.h>
		#include <linux/slab.h>
		#include <linux/clk.h>

		#include <linux/fsl/ptp_qoriq.h>

		@@ -317,6 +318,105 @@ static const struct ptp_clock_info ptp_qoriq_caps = {
		.enable = ptp_qoriq_enable,
		};

		/**
		* qoriq_ptp_nominal_freq - calculate nominal frequency according to
		* reference clock frequency
		*
		* @clk_src: reference clock frequency
		*
		* The nominal frequency is the desired clock frequency.
		* It should be less than the reference clock frequency.
		* It should be a factor of 1000MHz.
		*
		* Return the nominal frequency
		*/
		static u32 qoriq_ptp_nominal_freq(u32 clk_src)
		{
		u32 remainder = 0;

		clk_src /= 1000000;
		remainder = clk_src % 100;
		if (remainder) {
		clk_src -= remainder;
		clk_src += 100;
		}

		do {
		clk_src -= 100;

		} while (1000 % clk_src);

		return clk_src * 1000000;
		}

		/**
		* qoriq_ptp_auto_config - calculate a set of default configurations
		*
		* @qoriq_ptp: pointer to qoriq_ptp
		* @node: pointer to device_node
		*
		* If below dts properties are not provided, this function will be
		* called to calculate a set of default configurations for them.
		* "fsl,tclk-period"
		* "fsl,tmr-prsc"
		* "fsl,tmr-add"
		* "fsl,tmr-fiper1"
		* "fsl,tmr-fiper2"
		* "fsl,max-adj"
		*
		* Return 0 if success
		*/
		static int qoriq_ptp_auto_config(struct qoriq_ptp *qoriq_ptp,
		struct device_node *node)
		{
		struct clk *clk;
		u64 freq_comp;
		u64 max_adj;
		u32 nominal_freq;
		u32 clk_src = 0;

		qoriq_ptp->cksel = DEFAULT_CKSEL;

		clk = of_clk_get(node, 0);
		if (!IS_ERR(clk)) {
		clk_src = clk_get_rate(clk);
		clk_put(clk);
		}

		if (clk_src <= 100000000UL) {
		pr_err("error reference clock value, or lower than 100MHz\n");
		return -EINVAL;
		}

		nominal_freq = qoriq_ptp_nominal_freq(clk_src);
		if (!nominal_freq)
		return -EINVAL;

		qoriq_ptp->tclk_period = 1000000000UL / nominal_freq;
		qoriq_ptp->tmr_prsc = DEFAULT_TMR_PRSC;

		/* Calculate initial frequency compensation value for TMR_ADD register.
		* freq_comp = ceil(2^32 / freq_ratio)
		* freq_ratio = reference_clock_freq / nominal_freq
		*/
		freq_comp = ((u64)1 << 32) * nominal_freq;
		if (do_div(freq_comp, clk_src))
		freq_comp++;

		qoriq_ptp->tmr_add = freq_comp;
		qoriq_ptp->tmr_fiper1 = DEFAULT_FIPER1_PERIOD - qoriq_ptp->tclk_period;
		qoriq_ptp->tmr_fiper2 = DEFAULT_FIPER2_PERIOD - qoriq_ptp->tclk_period;

		/* max_adj = 1000000000 * (freq_ratio - 1.0) - 1
		* freq_ratio = reference_clock_freq / nominal_freq
		*/
		max_adj = 1000000000ULL * (clk_src - nominal_freq);
		max_adj = max_adj / nominal_freq - 1;
		qoriq_ptp->caps.max_adj = max_adj;

		return 0;
		}

		static int qoriq_ptp_probe(struct platform_device *dev)
		{
		struct device_node *node = dev->dev.of_node;
		@@ -332,7 +432,7 @@ static int qoriq_ptp_probe(struct platform_device *dev)
		if (!qoriq_ptp)
		goto no_memory;

		err = -ENODEV;
		err = -EINVAL;

		qoriq_ptp->caps = ptp_qoriq_caps;

		@@ -351,10 +451,14 @@ static int qoriq_ptp_probe(struct platform_device *dev)
		"fsl,tmr-fiper2", &qoriq_ptp->tmr_fiper2) \|\|
		of_property_read_u32(node,
		"fsl,max-adj", &qoriq_ptp->caps.max_adj)) {
		pr_err("device tree node missing required elements\n");
		goto no_node;
		pr_warn("device tree node missing required elements, try automatic configuration\n");

		if (qoriq_ptp_auto_config(qoriq_ptp, node))
		goto no_config;
		}

		err = -ENODEV;

		qoriq_ptp->irq = platform_get_irq(dev, 0);

		if (qoriq_ptp->irq < 0) {
		@@ -436,6 +540,7 @@ no_ioremap:
		release_resource(qoriq_ptp->rsrc);
		no_resource:
		free_irq(qoriq_ptp->irq, qoriq_ptp);
		no_config:
		no_node:
		kfree(qoriq_ptp);
		no_memory:

include/linux/fsl/ptp_qoriq.h

+5 −1

Original line number	Diff line number	Diff line
		@@ -127,9 +127,13 @@ struct qoriq_ptp_registers {


		#define DRIVER "ptp_qoriq"
		#define DEFAULT_CKSEL 1
		#define N_EXT_TS 2

		#define DEFAULT_CKSEL 1
		#define DEFAULT_TMR_PRSC 2
		#define DEFAULT_FIPER1_PERIOD 1000000000
		#define DEFAULT_FIPER2_PERIOD 100000

		struct qoriq_ptp {
		void __iomem *base;
		struct qoriq_ptp_registers regs;

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