Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 781 insertions, 0 deletions

diff --git a/drivers/cpufreq/brcmstb-avs-cpufreq.c b/drivers/cpufreq/brcmstb-avs-cpufreq.c
new file mode 100644
index 0000000000..35fb3a559e
--- /dev/null
+++ b/drivers/cpufreq/brcmstb-avs-cpufreq.c
@@ -0,0 +1,781 @@
+/*
+ * CPU frequency scaling for Broadcom SoCs with AVS firmware that
+ * supports DVS or DVFS
+ *
+ * Copyright (c) 2016 Broadcom
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+/*
+ * "AVS" is the name of a firmware developed at Broadcom. It derives
+ * its name from the technique called "Adaptive Voltage Scaling".
+ * Adaptive voltage scaling was the original purpose of this firmware.
+ * The AVS firmware still supports "AVS mode", where all it does is
+ * adaptive voltage scaling. However, on some newer Broadcom SoCs, the
+ * AVS Firmware, despite its unchanged name, also supports DFS mode and
+ * DVFS mode.
+ *
+ * In the context of this document and the related driver, "AVS" by
+ * itself always means the Broadcom firmware and never refers to the
+ * technique called "Adaptive Voltage Scaling".
+ *
+ * The Broadcom STB AVS CPUfreq driver provides voltage and frequency
+ * scaling on Broadcom SoCs using AVS firmware with support for DFS and
+ * DVFS. The AVS firmware is running on its own co-processor. The
+ * driver supports both uniprocessor (UP) and symmetric multiprocessor
+ * (SMP) systems which share clock and voltage across all CPUs.
+ *
+ * Actual voltage and frequency scaling is done solely by the AVS
+ * firmware. This driver does not change frequency or voltage itself.
+ * It provides a standard CPUfreq interface to the rest of the kernel
+ * and to userland. It interfaces with the AVS firmware to effect the
+ * requested changes and to report back the current system status in a
+ * way that is expected by existing tools.
+ */
+
+#include <linux/cpufreq.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/semaphore.h>
+
+/* Max number of arguments AVS calls take */
+#define AVS_MAX_CMD_ARGS	4
+/*
+ * This macro is used to generate AVS parameter register offsets. For
+ * x >= AVS_MAX_CMD_ARGS, it returns 0 to protect against accidental memory
+ * access outside of the parameter range. (Offset 0 is the first parameter.)
+ */
+#define AVS_PARAM_MULT(x)	((x) < AVS_MAX_CMD_ARGS ? (x) : 0)
+
+/* AVS Mailbox Register offsets */
+#define AVS_MBOX_COMMAND	0x00
+#define AVS_MBOX_STATUS		0x04
+#define AVS_MBOX_VOLTAGE0	0x08
+#define AVS_MBOX_TEMP0		0x0c
+#define AVS_MBOX_PV0		0x10
+#define AVS_MBOX_MV0		0x14
+#define AVS_MBOX_PARAM(x)	(0x18 + AVS_PARAM_MULT(x) * sizeof(u32))
+#define AVS_MBOX_REVISION	0x28
+#define AVS_MBOX_PSTATE		0x2c
+#define AVS_MBOX_HEARTBEAT	0x30
+#define AVS_MBOX_MAGIC		0x34
+#define AVS_MBOX_SIGMA_HVT	0x38
+#define AVS_MBOX_SIGMA_SVT	0x3c
+#define AVS_MBOX_VOLTAGE1	0x40
+#define AVS_MBOX_TEMP1		0x44
+#define AVS_MBOX_PV1		0x48
+#define AVS_MBOX_MV1		0x4c
+#define AVS_MBOX_FREQUENCY	0x50
+
+/* AVS Commands */
+#define AVS_CMD_AVAILABLE	0x00
+#define AVS_CMD_DISABLE		0x10
+#define AVS_CMD_ENABLE		0x11
+#define AVS_CMD_S2_ENTER	0x12
+#define AVS_CMD_S2_EXIT		0x13
+#define AVS_CMD_BBM_ENTER	0x14
+#define AVS_CMD_BBM_EXIT	0x15
+#define AVS_CMD_S3_ENTER	0x16
+#define AVS_CMD_S3_EXIT		0x17
+#define AVS_CMD_BALANCE		0x18
+/* PMAP and P-STATE commands */
+#define AVS_CMD_GET_PMAP	0x30
+#define AVS_CMD_SET_PMAP	0x31
+#define AVS_CMD_GET_PSTATE	0x40
+#define AVS_CMD_SET_PSTATE	0x41
+
+/* Different modes AVS supports (for GET_PMAP/SET_PMAP) */
+#define AVS_MODE_AVS		0x0
+#define AVS_MODE_DFS		0x1
+#define AVS_MODE_DVS		0x2
+#define AVS_MODE_DVFS		0x3
+
+/*
+ * PMAP parameter p1
+ * unused:31-24, mdiv_p0:23-16, unused:15-14, pdiv:13-10 , ndiv_int:9-0
+ */
+#define NDIV_INT_SHIFT		0
+#define NDIV_INT_MASK		0x3ff
+#define PDIV_SHIFT		10
+#define PDIV_MASK		0xf
+#define MDIV_P0_SHIFT		16
+#define MDIV_P0_MASK		0xff
+/*
+ * PMAP parameter p2
+ * mdiv_p4:31-24, mdiv_p3:23-16, mdiv_p2:15:8, mdiv_p1:7:0
+ */
+#define MDIV_P1_SHIFT		0
+#define MDIV_P1_MASK		0xff
+#define MDIV_P2_SHIFT		8
+#define MDIV_P2_MASK		0xff
+#define MDIV_P3_SHIFT		16
+#define MDIV_P3_MASK		0xff
+#define MDIV_P4_SHIFT		24
+#define MDIV_P4_MASK		0xff
+
+/* Different P-STATES AVS supports (for GET_PSTATE/SET_PSTATE) */
+#define AVS_PSTATE_P0		0x0
+#define AVS_PSTATE_P1		0x1
+#define AVS_PSTATE_P2		0x2
+#define AVS_PSTATE_P3		0x3
+#define AVS_PSTATE_P4		0x4
+#define AVS_PSTATE_MAX		AVS_PSTATE_P4
+
+/* CPU L2 Interrupt Controller Registers */
+#define AVS_CPU_L2_SET0		0x04
+#define AVS_CPU_L2_INT_MASK	BIT(31)
+
+/* AVS Command Status Values */
+#define AVS_STATUS_CLEAR	0x00
+/* Command/notification accepted */
+#define AVS_STATUS_SUCCESS	0xf0
+/* Command/notification rejected */
+#define AVS_STATUS_FAILURE	0xff
+/* Invalid command/notification (unknown) */
+#define AVS_STATUS_INVALID	0xf1
+/* Non-AVS modes are not supported */
+#define AVS_STATUS_NO_SUPP	0xf2
+/* Cannot set P-State until P-Map supplied */
+#define AVS_STATUS_NO_MAP	0xf3
+/* Cannot change P-Map after initial P-Map set */
+#define AVS_STATUS_MAP_SET	0xf4
+/* Max AVS status; higher numbers are used for debugging */
+#define AVS_STATUS_MAX		0xff
+
+/* Other AVS related constants */
+#define AVS_LOOP_LIMIT		10000
+#define AVS_TIMEOUT		300 /* in ms; expected completion is < 10ms */
+#define AVS_FIRMWARE_MAGIC	0xa11600d1
+
+#define BRCM_AVS_CPUFREQ_PREFIX	"brcmstb-avs"
+#define BRCM_AVS_CPUFREQ_NAME	BRCM_AVS_CPUFREQ_PREFIX "-cpufreq"
+#define BRCM_AVS_CPU_DATA	"brcm,avs-cpu-data-mem"
+#define BRCM_AVS_CPU_INTR	"brcm,avs-cpu-l2-intr"
+#define BRCM_AVS_HOST_INTR	"sw_intr"
+
+struct pmap {
+	unsigned int mode;
+	unsigned int p1;
+	unsigned int p2;
+	unsigned int state;
+};
+
+struct private_data {
+	void __iomem *base;
+	void __iomem *avs_intr_base;
+	struct device *dev;
+	struct completion done;
+	struct semaphore sem;
+	struct pmap pmap;
+	int host_irq;
+};
+
+static void __iomem *__map_region(const char *name)
+{
+	struct device_node *np;
+	void __iomem *ptr;
+
+	np = of_find_compatible_node(NULL, NULL, name);
+	if (!np)
+		return NULL;
+
+	ptr = of_iomap(np, 0);
+	of_node_put(np);
+
+	return ptr;
+}
+
+static unsigned long wait_for_avs_command(struct private_data *priv,
+					  unsigned long timeout)
+{
+	unsigned long time_left = 0;
+	u32 val;
+
+	/* Event driven, wait for the command interrupt */
+	if (priv->host_irq >= 0)
+		return wait_for_completion_timeout(&priv->done,
+						   msecs_to_jiffies(timeout));
+
+	/* Polling for command completion */
+	do {
+		time_left = timeout;
+		val = readl(priv->base + AVS_MBOX_STATUS);
+		if (val)
+			break;
+
+		usleep_range(1000, 2000);
+	} while (--timeout);
+
+	return time_left;
+}
+
+static int __issue_avs_command(struct private_data *priv, unsigned int cmd,
+			       unsigned int num_in, unsigned int num_out,
+			       u32 args[])
+{
+	void __iomem *base = priv->base;
+	unsigned long time_left;
+	unsigned int i;
+	int ret;
+	u32 val;
+
+	ret = down_interruptible(&priv->sem);
+	if (ret)
+		return ret;
+
+	/*
+	 * Make sure no other command is currently running: cmd is 0 if AVS
+	 * co-processor is idle. Due to the guard above, we should almost never
+	 * have to wait here.
+	 */
+	for (i = 0, val = 1; val != 0 && i < AVS_LOOP_LIMIT; i++)
+		val = readl(base + AVS_MBOX_COMMAND);
+
+	/* Give the caller a chance to retry if AVS is busy. */
+	if (i == AVS_LOOP_LIMIT) {
+		ret = -EAGAIN;
+		goto out;
+	}
+
+	/* Clear status before we begin. */
+	writel(AVS_STATUS_CLEAR, base + AVS_MBOX_STATUS);
+
+	/* Provide input parameters */
+	for (i = 0; i < num_in; i++)
+		writel(args[i], base + AVS_MBOX_PARAM(i));
+
+	/* Protect from spurious interrupts. */
+	reinit_completion(&priv->done);
+
+	/* Now issue the command & tell firmware to wake up to process it. */
+	writel(cmd, base + AVS_MBOX_COMMAND);
+	writel(AVS_CPU_L2_INT_MASK, priv->avs_intr_base + AVS_CPU_L2_SET0);
+
+	/* Wait for AVS co-processor to finish processing the command. */
+	time_left = wait_for_avs_command(priv, AVS_TIMEOUT);
+
+	/*
+	 * If the AVS status is not in the expected range, it means AVS didn't
+	 * complete our command in time, and we return an error. Also, if there
+	 * is no "time left", we timed out waiting for the interrupt.
+	 */
+	val = readl(base + AVS_MBOX_STATUS);
+	if (time_left == 0 || val == 0 || val > AVS_STATUS_MAX) {
+		dev_err(priv->dev, "AVS command %#x didn't complete in time\n",
+			cmd);
+		dev_err(priv->dev, "    Time left: %u ms, AVS status: %#x\n",
+			jiffies_to_msecs(time_left), val);
+		ret = -ETIMEDOUT;
+		goto out;
+	}
+
+	/* Process returned values */
+	for (i = 0; i < num_out; i++)
+		args[i] = readl(base + AVS_MBOX_PARAM(i));
+
+	/* Clear status to tell AVS co-processor we are done. */
+	writel(AVS_STATUS_CLEAR, base + AVS_MBOX_STATUS);
+
+	/* Convert firmware errors to errno's as much as possible. */
+	switch (val) {
+	case AVS_STATUS_INVALID:
+		ret = -EINVAL;
+		break;
+	case AVS_STATUS_NO_SUPP:
+		ret = -ENOTSUPP;
+		break;
+	case AVS_STATUS_NO_MAP:
+		ret = -ENOENT;
+		break;
+	case AVS_STATUS_MAP_SET:
+		ret = -EEXIST;
+		break;
+	case AVS_STATUS_FAILURE:
+		ret = -EIO;
+		break;
+	}
+
+out:
+	up(&priv->sem);
+
+	return ret;
+}
+
+static irqreturn_t irq_handler(int irq, void *data)
+{
+	struct private_data *priv = data;
+
+	/* AVS command completed execution. Wake up __issue_avs_command(). */
+	complete(&priv->done);
+
+	return IRQ_HANDLED;
+}
+
+static char *brcm_avs_mode_to_string(unsigned int mode)
+{
+	switch (mode) {
+	case AVS_MODE_AVS:
+		return "AVS";
+	case AVS_MODE_DFS:
+		return "DFS";
+	case AVS_MODE_DVS:
+		return "DVS";
+	case AVS_MODE_DVFS:
+		return "DVFS";
+	}
+	return NULL;
+}
+
+static void brcm_avs_parse_p1(u32 p1, unsigned int *mdiv_p0, unsigned int *pdiv,
+			      unsigned int *ndiv)
+{
+	*mdiv_p0 = (p1 >> MDIV_P0_SHIFT) & MDIV_P0_MASK;
+	*pdiv = (p1 >> PDIV_SHIFT) & PDIV_MASK;
+	*ndiv = (p1 >> NDIV_INT_SHIFT) & NDIV_INT_MASK;
+}
+
+static void brcm_avs_parse_p2(u32 p2, unsigned int *mdiv_p1,
+			      unsigned int *mdiv_p2, unsigned int *mdiv_p3,
+			      unsigned int *mdiv_p4)
+{
+	*mdiv_p4 = (p2 >> MDIV_P4_SHIFT) & MDIV_P4_MASK;
+	*mdiv_p3 = (p2 >> MDIV_P3_SHIFT) & MDIV_P3_MASK;
+	*mdiv_p2 = (p2 >> MDIV_P2_SHIFT) & MDIV_P2_MASK;
+	*mdiv_p1 = (p2 >> MDIV_P1_SHIFT) & MDIV_P1_MASK;
+}
+
+static int brcm_avs_get_pmap(struct private_data *priv, struct pmap *pmap)
+{
+	u32 args[AVS_MAX_CMD_ARGS];
+	int ret;
+
+	ret = __issue_avs_command(priv, AVS_CMD_GET_PMAP, 0, 4, args);
+	if (ret || !pmap)
+		return ret;
+
+	pmap->mode = args[0];
+	pmap->p1 = args[1];
+	pmap->p2 = args[2];
+	pmap->state = args[3];
+
+	return 0;
+}
+
+static int brcm_avs_set_pmap(struct private_data *priv, struct pmap *pmap)
+{
+	u32 args[AVS_MAX_CMD_ARGS];
+
+	args[0] = pmap->mode;
+	args[1] = pmap->p1;
+	args[2] = pmap->p2;
+	args[3] = pmap->state;
+
+	return __issue_avs_command(priv, AVS_CMD_SET_PMAP, 4, 0, args);
+}
+
+static int brcm_avs_get_pstate(struct private_data *priv, unsigned int *pstate)
+{
+	u32 args[AVS_MAX_CMD_ARGS];
+	int ret;
+
+	ret = __issue_avs_command(priv, AVS_CMD_GET_PSTATE, 0, 1, args);
+	if (ret)
+		return ret;
+	*pstate = args[0];
+
+	return 0;
+}
+
+static int brcm_avs_set_pstate(struct private_data *priv, unsigned int pstate)
+{
+	u32 args[AVS_MAX_CMD_ARGS];
+
+	args[0] = pstate;
+
+	return __issue_avs_command(priv, AVS_CMD_SET_PSTATE, 1, 0, args);
+
+}
+
+static u32 brcm_avs_get_voltage(void __iomem *base)
+{
+	return readl(base + AVS_MBOX_VOLTAGE1);
+}
+
+static u32 brcm_avs_get_frequency(void __iomem *base)
+{
+	return readl(base + AVS_MBOX_FREQUENCY) * 1000;	/* in kHz */
+}
+
+/*
+ * We determine which frequencies are supported by cycling through all P-states
+ * and reading back what frequency we are running at for each P-state.
+ */
+static struct cpufreq_frequency_table *
+brcm_avs_get_freq_table(struct device *dev, struct private_data *priv)
+{
+	struct cpufreq_frequency_table *table;
+	unsigned int pstate;
+	int i, ret;
+
+	/* Remember P-state for later */
+	ret = brcm_avs_get_pstate(priv, &pstate);
+	if (ret)
+		return ERR_PTR(ret);
+
+	/*
+	 * We allocate space for the 5 different P-STATES AVS,
+	 * plus extra space for a terminating element.
+	 */
+	table = devm_kcalloc(dev, AVS_PSTATE_MAX + 1 + 1, sizeof(*table),
+			     GFP_KERNEL);
+	if (!table)
+		return ERR_PTR(-ENOMEM);
+
+	for (i = AVS_PSTATE_P0; i <= AVS_PSTATE_MAX; i++) {
+		ret = brcm_avs_set_pstate(priv, i);
+		if (ret)
+			return ERR_PTR(ret);
+		table[i].frequency = brcm_avs_get_frequency(priv->base);
+		table[i].driver_data = i;
+	}
+	table[i].frequency = CPUFREQ_TABLE_END;
+
+	/* Restore P-state */
+	ret = brcm_avs_set_pstate(priv, pstate);
+	if (ret)
+		return ERR_PTR(ret);
+
+	return table;
+}
+
+/*
+ * To ensure the right firmware is running we need to
+ *    - check the MAGIC matches what we expect
+ *    - brcm_avs_get_pmap() doesn't return -ENOTSUPP or -EINVAL
+ * We need to set up our interrupt handling before calling brcm_avs_get_pmap()!
+ */
+static bool brcm_avs_is_firmware_loaded(struct private_data *priv)
+{
+	u32 magic;
+	int rc;
+
+	rc = brcm_avs_get_pmap(priv, NULL);
+	magic = readl(priv->base + AVS_MBOX_MAGIC);
+
+	return (magic == AVS_FIRMWARE_MAGIC) && ((rc != -ENOTSUPP) ||
+		(rc != -EINVAL));
+}
+
+static unsigned int brcm_avs_cpufreq_get(unsigned int cpu)
+{
+	struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
+	struct private_data *priv = policy->driver_data;
+
+	cpufreq_cpu_put(policy);
+
+	return brcm_avs_get_frequency(priv->base);
+}
+
+static int brcm_avs_target_index(struct cpufreq_policy *policy,
+				 unsigned int index)
+{
+	return brcm_avs_set_pstate(policy->driver_data,
+				  policy->freq_table[index].driver_data);
+}
+
+static int brcm_avs_suspend(struct cpufreq_policy *policy)
+{
+	struct private_data *priv = policy->driver_data;
+	int ret;
+
+	ret = brcm_avs_get_pmap(priv, &priv->pmap);
+	if (ret)
+		return ret;
+
+	/*
+	 * We can't use the P-state returned by brcm_avs_get_pmap(), since
+	 * that's the initial P-state from when the P-map was downloaded to the
+	 * AVS co-processor, not necessarily the P-state we are running at now.
+	 * So, we get the current P-state explicitly.
+	 */
+	ret = brcm_avs_get_pstate(priv, &priv->pmap.state);
+	if (ret)
+		return ret;
+
+	/* This is best effort. Nothing to do if it fails. */
+	(void)__issue_avs_command(priv, AVS_CMD_S2_ENTER, 0, 0, NULL);
+
+	return 0;
+}
+
+static int brcm_avs_resume(struct cpufreq_policy *policy)
+{
+	struct private_data *priv = policy->driver_data;
+	int ret;
+
+	/* This is best effort. Nothing to do if it fails. */
+	(void)__issue_avs_command(priv, AVS_CMD_S2_EXIT, 0, 0, NULL);
+
+	ret = brcm_avs_set_pmap(priv, &priv->pmap);
+	if (ret == -EEXIST) {
+		struct platform_device *pdev  = cpufreq_get_driver_data();
+		struct device *dev = &pdev->dev;
+
+		dev_warn(dev, "PMAP was already set\n");
+		ret = 0;
+	}
+
+	return ret;
+}
+
+/*
+ * All initialization code that we only want to execute once goes here. Setup
+ * code that can be re-tried on every core (if it failed before) can go into
+ * brcm_avs_cpufreq_init().
+ */
+static int brcm_avs_prepare_init(struct platform_device *pdev)
+{
+	struct private_data *priv;
+	struct device *dev;
+	int ret;
+
+	dev = &pdev->dev;
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->dev = dev;
+	sema_init(&priv->sem, 1);
+	init_completion(&priv->done);
+	platform_set_drvdata(pdev, priv);
+
+	priv->base = __map_region(BRCM_AVS_CPU_DATA);
+	if (!priv->base) {
+		dev_err(dev, "Couldn't find property %s in device tree.\n",
+			BRCM_AVS_CPU_DATA);
+		return -ENOENT;
+	}
+
+	priv->avs_intr_base = __map_region(BRCM_AVS_CPU_INTR);
+	if (!priv->avs_intr_base) {
+		dev_err(dev, "Couldn't find property %s in device tree.\n",
+			BRCM_AVS_CPU_INTR);
+		ret = -ENOENT;
+		goto unmap_base;
+	}
+
+	priv->host_irq = platform_get_irq_byname(pdev, BRCM_AVS_HOST_INTR);
+
+	ret = devm_request_irq(dev, priv->host_irq, irq_handler,
+			       IRQF_TRIGGER_RISING,
+			       BRCM_AVS_HOST_INTR, priv);
+	if (ret && priv->host_irq >= 0) {
+		dev_err(dev, "IRQ request failed: %s (%d) -- %d\n",
+			BRCM_AVS_HOST_INTR, priv->host_irq, ret);
+		goto unmap_intr_base;
+	}
+
+	if (brcm_avs_is_firmware_loaded(priv))
+		return 0;
+
+	dev_err(dev, "AVS firmware is not loaded or doesn't support DVFS\n");
+	ret = -ENODEV;
+
+unmap_intr_base:
+	iounmap(priv->avs_intr_base);
+unmap_base:
+	iounmap(priv->base);
+
+	return ret;
+}
+
+static void brcm_avs_prepare_uninit(struct platform_device *pdev)
+{
+	struct private_data *priv;
+
+	priv = platform_get_drvdata(pdev);
+
+	iounmap(priv->avs_intr_base);
+	iounmap(priv->base);
+}
+
+static int brcm_avs_cpufreq_init(struct cpufreq_policy *policy)
+{
+	struct cpufreq_frequency_table *freq_table;
+	struct platform_device *pdev;
+	struct private_data *priv;
+	struct device *dev;
+	int ret;
+
+	pdev = cpufreq_get_driver_data();
+	priv = platform_get_drvdata(pdev);
+	policy->driver_data = priv;
+	dev = &pdev->dev;
+
+	freq_table = brcm_avs_get_freq_table(dev, priv);
+	if (IS_ERR(freq_table)) {
+		ret = PTR_ERR(freq_table);
+		dev_err(dev, "Couldn't determine frequency table (%d).\n", ret);
+		return ret;
+	}
+
+	policy->freq_table = freq_table;
+
+	/* All cores share the same clock and thus the same policy. */
+	cpumask_setall(policy->cpus);
+
+	ret = __issue_avs_command(priv, AVS_CMD_ENABLE, 0, 0, NULL);
+	if (!ret) {
+		unsigned int pstate;
+
+		ret = brcm_avs_get_pstate(priv, &pstate);
+		if (!ret) {
+			policy->cur = freq_table[pstate].frequency;
+			dev_info(dev, "registered\n");
+			return 0;
+		}
+	}
+
+	dev_err(dev, "couldn't initialize driver (%d)\n", ret);
+
+	return ret;
+}
+
+static ssize_t show_brcm_avs_pstate(struct cpufreq_policy *policy, char *buf)
+{
+	struct private_data *priv = policy->driver_data;
+	unsigned int pstate;
+
+	if (brcm_avs_get_pstate(priv, &pstate))
+		return sprintf(buf, "<unknown>\n");
+
+	return sprintf(buf, "%u\n", pstate);
+}
+
+static ssize_t show_brcm_avs_mode(struct cpufreq_policy *policy, char *buf)
+{
+	struct private_data *priv = policy->driver_data;
+	struct pmap pmap;
+
+	if (brcm_avs_get_pmap(priv, &pmap))
+		return sprintf(buf, "<unknown>\n");
+
+	return sprintf(buf, "%s %u\n", brcm_avs_mode_to_string(pmap.mode),
+		pmap.mode);
+}
+
+static ssize_t show_brcm_avs_pmap(struct cpufreq_policy *policy, char *buf)
+{
+	unsigned int mdiv_p0, mdiv_p1, mdiv_p2, mdiv_p3, mdiv_p4;
+	struct private_data *priv = policy->driver_data;
+	unsigned int ndiv, pdiv;
+	struct pmap pmap;
+
+	if (brcm_avs_get_pmap(priv, &pmap))
+		return sprintf(buf, "<unknown>\n");
+
+	brcm_avs_parse_p1(pmap.p1, &mdiv_p0, &pdiv, &ndiv);
+	brcm_avs_parse_p2(pmap.p2, &mdiv_p1, &mdiv_p2, &mdiv_p3, &mdiv_p4);
+
+	return sprintf(buf, "0x%08x 0x%08x %u %u %u %u %u %u %u %u %u\n",
+		pmap.p1, pmap.p2, ndiv, pdiv, mdiv_p0, mdiv_p1, mdiv_p2,
+		mdiv_p3, mdiv_p4, pmap.mode, pmap.state);
+}
+
+static ssize_t show_brcm_avs_voltage(struct cpufreq_policy *policy, char *buf)
+{
+	struct private_data *priv = policy->driver_data;
+
+	return sprintf(buf, "0x%08x\n", brcm_avs_get_voltage(priv->base));
+}
+
+static ssize_t show_brcm_avs_frequency(struct cpufreq_policy *policy, char *buf)
+{
+	struct private_data *priv = policy->driver_data;
+
+	return sprintf(buf, "0x%08x\n", brcm_avs_get_frequency(priv->base));
+}
+
+cpufreq_freq_attr_ro(brcm_avs_pstate);
+cpufreq_freq_attr_ro(brcm_avs_mode);
+cpufreq_freq_attr_ro(brcm_avs_pmap);
+cpufreq_freq_attr_ro(brcm_avs_voltage);
+cpufreq_freq_attr_ro(brcm_avs_frequency);
+
+static struct freq_attr *brcm_avs_cpufreq_attr[] = {
+	&cpufreq_freq_attr_scaling_available_freqs,
+	&brcm_avs_pstate,
+	&brcm_avs_mode,
+	&brcm_avs_pmap,
+	&brcm_avs_voltage,
+	&brcm_avs_frequency,
+	NULL
+};
+
+static struct cpufreq_driver brcm_avs_driver = {
+	.flags		= CPUFREQ_NEED_INITIAL_FREQ_CHECK,
+	.verify		= cpufreq_generic_frequency_table_verify,
+	.target_index	= brcm_avs_target_index,
+	.get		= brcm_avs_cpufreq_get,
+	.suspend	= brcm_avs_suspend,
+	.resume		= brcm_avs_resume,
+	.init		= brcm_avs_cpufreq_init,
+	.attr		= brcm_avs_cpufreq_attr,
+	.name		= BRCM_AVS_CPUFREQ_PREFIX,
+};
+
+static int brcm_avs_cpufreq_probe(struct platform_device *pdev)
+{
+	int ret;
+
+	ret = brcm_avs_prepare_init(pdev);
+	if (ret)
+		return ret;
+
+	brcm_avs_driver.driver_data = pdev;
+
+	ret = cpufreq_register_driver(&brcm_avs_driver);
+	if (ret)
+		brcm_avs_prepare_uninit(pdev);
+
+	return ret;
+}
+
+static void brcm_avs_cpufreq_remove(struct platform_device *pdev)
+{
+	cpufreq_unregister_driver(&brcm_avs_driver);
+
+	brcm_avs_prepare_uninit(pdev);
+}
+
+static const struct of_device_id brcm_avs_cpufreq_match[] = {
+	{ .compatible = BRCM_AVS_CPU_DATA },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, brcm_avs_cpufreq_match);
+
+static struct platform_driver brcm_avs_cpufreq_platdrv = {
+	.driver = {
+		.name	= BRCM_AVS_CPUFREQ_NAME,
+		.of_match_table = brcm_avs_cpufreq_match,
+	},
+	.probe		= brcm_avs_cpufreq_probe,
+	.remove_new	= brcm_avs_cpufreq_remove,
+};
+module_platform_driver(brcm_avs_cpufreq_platdrv);
+
+MODULE_AUTHOR("Markus Mayer <mmayer@broadcom.com>");
+MODULE_DESCRIPTION("CPUfreq driver for Broadcom STB AVS");
+MODULE_LICENSE("GPL");