Initial import

1 files changed, 368 insertions, 0 deletions

diff --git a/drivers/cpufreq/imx6q-cpufreq.c b/drivers/cpufreq/imx6q-cpufreq.c
new file mode 100644
index 000000000..380a90d3c
--- /dev/null
+++ b/drivers/cpufreq/imx6q-cpufreq.c
@@ -0,0 +1,368 @@
+/*
+ * Copyright (C) 2013 Freescale Semiconductor, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/clk.h>
+#include <linux/cpu.h>
+#include <linux/cpufreq.h>
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/pm_opp.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+
+#define PU_SOC_VOLTAGE_NORMAL	1250000
+#define PU_SOC_VOLTAGE_HIGH	1275000
+#define FREQ_1P2_GHZ		1200000000
+
+static struct regulator *arm_reg;
+static struct regulator *pu_reg;
+static struct regulator *soc_reg;
+
+static struct clk *arm_clk;
+static struct clk *pll1_sys_clk;
+static struct clk *pll1_sw_clk;
+static struct clk *step_clk;
+static struct clk *pll2_pfd2_396m_clk;
+
+static struct device *cpu_dev;
+static bool free_opp;
+static struct cpufreq_frequency_table *freq_table;
+static unsigned int transition_latency;
+
+static u32 *imx6_soc_volt;
+static u32 soc_opp_count;
+
+static int imx6q_set_target(struct cpufreq_policy *policy, unsigned int index)
+{
+	struct dev_pm_opp *opp;
+	unsigned long freq_hz, volt, volt_old;
+	unsigned int old_freq, new_freq;
+	int ret;
+
+	new_freq = freq_table[index].frequency;
+	freq_hz = new_freq * 1000;
+	old_freq = clk_get_rate(arm_clk) / 1000;
+
+	rcu_read_lock();
+	opp = dev_pm_opp_find_freq_ceil(cpu_dev, &freq_hz);
+	if (IS_ERR(opp)) {
+		rcu_read_unlock();
+		dev_err(cpu_dev, "failed to find OPP for %ld\n", freq_hz);
+		return PTR_ERR(opp);
+	}
+
+	volt = dev_pm_opp_get_voltage(opp);
+	rcu_read_unlock();
+	volt_old = regulator_get_voltage(arm_reg);
+
+	dev_dbg(cpu_dev, "%u MHz, %ld mV --> %u MHz, %ld mV\n",
+		old_freq / 1000, volt_old / 1000,
+		new_freq / 1000, volt / 1000);
+
+	/* scaling up?  scale voltage before frequency */
+	if (new_freq > old_freq) {
+		if (!IS_ERR(pu_reg)) {
+			ret = regulator_set_voltage_tol(pu_reg, imx6_soc_volt[index], 0);
+			if (ret) {
+				dev_err(cpu_dev, "failed to scale vddpu up: %d\n", ret);
+				return ret;
+			}
+		}
+		ret = regulator_set_voltage_tol(soc_reg, imx6_soc_volt[index], 0);
+		if (ret) {
+			dev_err(cpu_dev, "failed to scale vddsoc up: %d\n", ret);
+			return ret;
+		}
+		ret = regulator_set_voltage_tol(arm_reg, volt, 0);
+		if (ret) {
+			dev_err(cpu_dev,
+				"failed to scale vddarm up: %d\n", ret);
+			return ret;
+		}
+	}
+
+	/*
+	 * The setpoints are selected per PLL/PDF frequencies, so we need to
+	 * reprogram PLL for frequency scaling.  The procedure of reprogramming
+	 * PLL1 is as below.
+	 *
+	 *  - Enable pll2_pfd2_396m_clk and reparent pll1_sw_clk to it
+	 *  - Reprogram pll1_sys_clk and reparent pll1_sw_clk back to it
+	 *  - Disable pll2_pfd2_396m_clk
+	 */
+	clk_set_parent(step_clk, pll2_pfd2_396m_clk);
+	clk_set_parent(pll1_sw_clk, step_clk);
+	if (freq_hz > clk_get_rate(pll2_pfd2_396m_clk)) {
+		clk_set_rate(pll1_sys_clk, new_freq * 1000);
+		clk_set_parent(pll1_sw_clk, pll1_sys_clk);
+	}
+
+	/* Ensure the arm clock divider is what we expect */
+	ret = clk_set_rate(arm_clk, new_freq * 1000);
+	if (ret) {
+		dev_err(cpu_dev, "failed to set clock rate: %d\n", ret);
+		regulator_set_voltage_tol(arm_reg, volt_old, 0);
+		return ret;
+	}
+
+	/* scaling down?  scale voltage after frequency */
+	if (new_freq < old_freq) {
+		ret = regulator_set_voltage_tol(arm_reg, volt, 0);
+		if (ret) {
+			dev_warn(cpu_dev,
+				 "failed to scale vddarm down: %d\n", ret);
+			ret = 0;
+		}
+		ret = regulator_set_voltage_tol(soc_reg, imx6_soc_volt[index], 0);
+		if (ret) {
+			dev_warn(cpu_dev, "failed to scale vddsoc down: %d\n", ret);
+			ret = 0;
+		}
+		if (!IS_ERR(pu_reg)) {
+			ret = regulator_set_voltage_tol(pu_reg, imx6_soc_volt[index], 0);
+			if (ret) {
+				dev_warn(cpu_dev, "failed to scale vddpu down: %d\n", ret);
+				ret = 0;
+			}
+		}
+	}
+
+	return 0;
+}
+
+static int imx6q_cpufreq_init(struct cpufreq_policy *policy)
+{
+	policy->clk = arm_clk;
+	return cpufreq_generic_init(policy, freq_table, transition_latency);
+}
+
+static struct cpufreq_driver imx6q_cpufreq_driver = {
+	.flags = CPUFREQ_NEED_INITIAL_FREQ_CHECK,
+	.verify = cpufreq_generic_frequency_table_verify,
+	.target_index = imx6q_set_target,
+	.get = cpufreq_generic_get,
+	.init = imx6q_cpufreq_init,
+	.name = "imx6q-cpufreq",
+	.attr = cpufreq_generic_attr,
+};
+
+static int imx6q_cpufreq_probe(struct platform_device *pdev)
+{
+	struct device_node *np;
+	struct dev_pm_opp *opp;
+	unsigned long min_volt, max_volt;
+	int num, ret;
+	const struct property *prop;
+	const __be32 *val;
+	u32 nr, i, j;
+
+	cpu_dev = get_cpu_device(0);
+	if (!cpu_dev) {
+		pr_err("failed to get cpu0 device\n");
+		return -ENODEV;
+	}
+
+	np = of_node_get(cpu_dev->of_node);
+	if (!np) {
+		dev_err(cpu_dev, "failed to find cpu0 node\n");
+		return -ENOENT;
+	}
+
+	arm_clk = clk_get(cpu_dev, "arm");
+	pll1_sys_clk = clk_get(cpu_dev, "pll1_sys");
+	pll1_sw_clk = clk_get(cpu_dev, "pll1_sw");
+	step_clk = clk_get(cpu_dev, "step");
+	pll2_pfd2_396m_clk = clk_get(cpu_dev, "pll2_pfd2_396m");
+	if (IS_ERR(arm_clk) || IS_ERR(pll1_sys_clk) || IS_ERR(pll1_sw_clk) ||
+	    IS_ERR(step_clk) || IS_ERR(pll2_pfd2_396m_clk)) {
+		dev_err(cpu_dev, "failed to get clocks\n");
+		ret = -ENOENT;
+		goto put_clk;
+	}
+
+	arm_reg = regulator_get(cpu_dev, "arm");
+	pu_reg = regulator_get_optional(cpu_dev, "pu");
+	soc_reg = regulator_get(cpu_dev, "soc");
+	if (IS_ERR(arm_reg) || IS_ERR(soc_reg)) {
+		dev_err(cpu_dev, "failed to get regulators\n");
+		ret = -ENOENT;
+		goto put_reg;
+	}
+
+	/*
+	 * We expect an OPP table supplied by platform.
+	 * Just, incase the platform did not supply the OPP
+	 * table, it will try to get it.
+	 */
+	num = dev_pm_opp_get_opp_count(cpu_dev);
+	if (num < 0) {
+		ret = of_init_opp_table(cpu_dev);
+		if (ret < 0) {
+			dev_err(cpu_dev, "failed to init OPP table: %d\n", ret);
+			goto put_reg;
+		}
+
+		/* Because we have added the OPPs here, we must free them */
+		free_opp = true;
+
+		num = dev_pm_opp_get_opp_count(cpu_dev);
+		if (num < 0) {
+			ret = num;
+			dev_err(cpu_dev, "no OPP table is found: %d\n", ret);
+			goto out_free_opp;
+		}
+	}
+
+	ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table);
+	if (ret) {
+		dev_err(cpu_dev, "failed to init cpufreq table: %d\n", ret);
+		goto put_reg;
+	}
+
+	/* Make imx6_soc_volt array's size same as arm opp number */
+	imx6_soc_volt = devm_kzalloc(cpu_dev, sizeof(*imx6_soc_volt) * num, GFP_KERNEL);
+	if (imx6_soc_volt == NULL) {
+		ret = -ENOMEM;
+		goto free_freq_table;
+	}
+
+	prop = of_find_property(np, "fsl,soc-operating-points", NULL);
+	if (!prop || !prop->value)
+		goto soc_opp_out;
+
+	/*
+	 * Each OPP is a set of tuples consisting of frequency and
+	 * voltage like <freq-kHz vol-uV>.
+	 */
+	nr = prop->length / sizeof(u32);
+	if (nr % 2 || (nr / 2) < num)
+		goto soc_opp_out;
+
+	for (j = 0; j < num; j++) {
+		val = prop->value;
+		for (i = 0; i < nr / 2; i++) {
+			unsigned long freq = be32_to_cpup(val++);
+			unsigned long volt = be32_to_cpup(val++);
+			if (freq_table[j].frequency == freq) {
+				imx6_soc_volt[soc_opp_count++] = volt;
+				break;
+			}
+		}
+	}
+
+soc_opp_out:
+	/* use fixed soc opp volt if no valid soc opp info found in dtb */
+	if (soc_opp_count != num) {
+		dev_warn(cpu_dev, "can NOT find valid fsl,soc-operating-points property in dtb, use default value!\n");
+		for (j = 0; j < num; j++)
+			imx6_soc_volt[j] = PU_SOC_VOLTAGE_NORMAL;
+		if (freq_table[num - 1].frequency * 1000 == FREQ_1P2_GHZ)
+			imx6_soc_volt[num - 1] = PU_SOC_VOLTAGE_HIGH;
+	}
+
+	if (of_property_read_u32(np, "clock-latency", &transition_latency))
+		transition_latency = CPUFREQ_ETERNAL;
+
+	/*
+	 * Calculate the ramp time for max voltage change in the
+	 * VDDSOC and VDDPU regulators.
+	 */
+	ret = regulator_set_voltage_time(soc_reg, imx6_soc_volt[0], imx6_soc_volt[num - 1]);
+	if (ret > 0)
+		transition_latency += ret * 1000;
+	if (!IS_ERR(pu_reg)) {
+		ret = regulator_set_voltage_time(pu_reg, imx6_soc_volt[0], imx6_soc_volt[num - 1]);
+		if (ret > 0)
+			transition_latency += ret * 1000;
+	}
+
+	/*
+	 * OPP is maintained in order of increasing frequency, and
+	 * freq_table initialised from OPP is therefore sorted in the
+	 * same order.
+	 */
+	rcu_read_lock();
+	opp = dev_pm_opp_find_freq_exact(cpu_dev,
+				  freq_table[0].frequency * 1000, true);
+	min_volt = dev_pm_opp_get_voltage(opp);
+	opp = dev_pm_opp_find_freq_exact(cpu_dev,
+				  freq_table[--num].frequency * 1000, true);
+	max_volt = dev_pm_opp_get_voltage(opp);
+	rcu_read_unlock();
+	ret = regulator_set_voltage_time(arm_reg, min_volt, max_volt);
+	if (ret > 0)
+		transition_latency += ret * 1000;
+
+	ret = cpufreq_register_driver(&imx6q_cpufreq_driver);
+	if (ret) {
+		dev_err(cpu_dev, "failed register driver: %d\n", ret);
+		goto free_freq_table;
+	}
+
+	of_node_put(np);
+	return 0;
+
+free_freq_table:
+	dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table);
+out_free_opp:
+	if (free_opp)
+		of_free_opp_table(cpu_dev);
+put_reg:
+	if (!IS_ERR(arm_reg))
+		regulator_put(arm_reg);
+	if (!IS_ERR(pu_reg))
+		regulator_put(pu_reg);
+	if (!IS_ERR(soc_reg))
+		regulator_put(soc_reg);
+put_clk:
+	if (!IS_ERR(arm_clk))
+		clk_put(arm_clk);
+	if (!IS_ERR(pll1_sys_clk))
+		clk_put(pll1_sys_clk);
+	if (!IS_ERR(pll1_sw_clk))
+		clk_put(pll1_sw_clk);
+	if (!IS_ERR(step_clk))
+		clk_put(step_clk);
+	if (!IS_ERR(pll2_pfd2_396m_clk))
+		clk_put(pll2_pfd2_396m_clk);
+	of_node_put(np);
+	return ret;
+}
+
+static int imx6q_cpufreq_remove(struct platform_device *pdev)
+{
+	cpufreq_unregister_driver(&imx6q_cpufreq_driver);
+	dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table);
+	if (free_opp)
+		of_free_opp_table(cpu_dev);
+	regulator_put(arm_reg);
+	if (!IS_ERR(pu_reg))
+		regulator_put(pu_reg);
+	regulator_put(soc_reg);
+	clk_put(arm_clk);
+	clk_put(pll1_sys_clk);
+	clk_put(pll1_sw_clk);
+	clk_put(step_clk);
+	clk_put(pll2_pfd2_396m_clk);
+
+	return 0;
+}
+
+static struct platform_driver imx6q_cpufreq_platdrv = {
+	.driver = {
+		.name	= "imx6q-cpufreq",
+	},
+	.probe		= imx6q_cpufreq_probe,
+	.remove		= imx6q_cpufreq_remove,
+};
+module_platform_driver(imx6q_cpufreq_platdrv);
+
+MODULE_AUTHOR("Shawn Guo <shawn.guo@linaro.org>");
+MODULE_DESCRIPTION("Freescale i.MX6Q cpufreq driver");
+MODULE_LICENSE("GPL");