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path: root/drivers/cpufreq/brcmstb-avs-cpufreq.c
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Diffstat (limited to 'drivers/cpufreq/brcmstb-avs-cpufreq.c')
-rw-r--r--drivers/cpufreq/brcmstb-avs-cpufreq.c1057
1 files changed, 1057 insertions, 0 deletions
diff --git a/drivers/cpufreq/brcmstb-avs-cpufreq.c b/drivers/cpufreq/brcmstb-avs-cpufreq.c
new file mode 100644
index 000000000000..4fda623e55bb
--- /dev/null
+++ b/drivers/cpufreq/brcmstb-avs-cpufreq.c
@@ -0,0 +1,1057 @@
+/*
+ * 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/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/semaphore.h>
+
+#ifdef CONFIG_ARM_BRCMSTB_AVS_CPUFREQ_DEBUG
+#include <linux/ctype.h>
+#include <linux/debugfs.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#endif
+
+/* 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;
+#ifdef CONFIG_ARM_BRCMSTB_AVS_CPUFREQ_DEBUG
+ struct dentry *debugfs;
+#endif
+ struct completion done;
+ struct semaphore sem;
+ struct pmap pmap;
+};
+
+#ifdef CONFIG_ARM_BRCMSTB_AVS_CPUFREQ_DEBUG
+
+enum debugfs_format {
+ DEBUGFS_NORMAL,
+ DEBUGFS_FLOAT,
+ DEBUGFS_REV,
+};
+
+struct debugfs_data {
+ struct debugfs_entry *entry;
+ struct private_data *priv;
+};
+
+struct debugfs_entry {
+ char *name;
+ u32 offset;
+ fmode_t mode;
+ enum debugfs_format format;
+};
+
+#define DEBUGFS_ENTRY(name, mode, format) { \
+ #name, AVS_MBOX_##name, mode, format \
+}
+
+/*
+ * These are used for debugfs only. Otherwise we use AVS_MBOX_PARAM() directly.
+ */
+#define AVS_MBOX_PARAM1 AVS_MBOX_PARAM(0)
+#define AVS_MBOX_PARAM2 AVS_MBOX_PARAM(1)
+#define AVS_MBOX_PARAM3 AVS_MBOX_PARAM(2)
+#define AVS_MBOX_PARAM4 AVS_MBOX_PARAM(3)
+
+/*
+ * This table stores the name, access permissions and offset for each hardware
+ * register and is used to generate debugfs entries.
+ */
+static struct debugfs_entry debugfs_entries[] = {
+ DEBUGFS_ENTRY(COMMAND, S_IWUSR, DEBUGFS_NORMAL),
+ DEBUGFS_ENTRY(STATUS, S_IWUSR, DEBUGFS_NORMAL),
+ DEBUGFS_ENTRY(VOLTAGE0, 0, DEBUGFS_FLOAT),
+ DEBUGFS_ENTRY(TEMP0, 0, DEBUGFS_FLOAT),
+ DEBUGFS_ENTRY(PV0, 0, DEBUGFS_FLOAT),
+ DEBUGFS_ENTRY(MV0, 0, DEBUGFS_FLOAT),
+ DEBUGFS_ENTRY(PARAM1, S_IWUSR, DEBUGFS_NORMAL),
+ DEBUGFS_ENTRY(PARAM2, S_IWUSR, DEBUGFS_NORMAL),
+ DEBUGFS_ENTRY(PARAM3, S_IWUSR, DEBUGFS_NORMAL),
+ DEBUGFS_ENTRY(PARAM4, S_IWUSR, DEBUGFS_NORMAL),
+ DEBUGFS_ENTRY(REVISION, 0, DEBUGFS_REV),
+ DEBUGFS_ENTRY(PSTATE, 0, DEBUGFS_NORMAL),
+ DEBUGFS_ENTRY(HEARTBEAT, 0, DEBUGFS_NORMAL),
+ DEBUGFS_ENTRY(MAGIC, S_IWUSR, DEBUGFS_NORMAL),
+ DEBUGFS_ENTRY(SIGMA_HVT, 0, DEBUGFS_NORMAL),
+ DEBUGFS_ENTRY(SIGMA_SVT, 0, DEBUGFS_NORMAL),
+ DEBUGFS_ENTRY(VOLTAGE1, 0, DEBUGFS_FLOAT),
+ DEBUGFS_ENTRY(TEMP1, 0, DEBUGFS_FLOAT),
+ DEBUGFS_ENTRY(PV1, 0, DEBUGFS_FLOAT),
+ DEBUGFS_ENTRY(MV1, 0, DEBUGFS_FLOAT),
+ DEBUGFS_ENTRY(FREQUENCY, 0, DEBUGFS_NORMAL),
+};
+
+static int brcm_avs_target_index(struct cpufreq_policy *, unsigned int);
+
+static char *__strtolower(char *s)
+{
+ char *p;
+
+ for (p = s; *p; p++)
+ *p = tolower(*p);
+
+ return s;
+}
+
+#endif /* CONFIG_ARM_BRCMSTB_AVS_CPUFREQ_DEBUG */
+
+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 int __issue_avs_command(struct private_data *priv, int cmd, bool is_send,
+ u32 args[])
+{
+ unsigned long time_left = msecs_to_jiffies(AVS_TIMEOUT);
+ void __iomem *base = priv->base;
+ 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);
+
+ /* We need to send arguments for this command. */
+ if (args && is_send) {
+ for (i = 0; i < AVS_MAX_CMD_ARGS; 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_completion_timeout(&priv->done, time_left);
+
+ /*
+ * 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;
+ }
+
+ /* This command returned arguments, so we read them back. */
+ if (args && !is_send) {
+ for (i = 0; i < AVS_MAX_CMD_ARGS; 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, false, 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, true, 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, false, 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, true, args);
+}
+
+static unsigned long brcm_avs_get_voltage(void __iomem *base)
+{
+ return readl(base + AVS_MBOX_VOLTAGE1);
+}
+
+static unsigned long 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);
+
+ table = devm_kzalloc(dev, (AVS_PSTATE_MAX + 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;
+}
+
+#ifdef CONFIG_ARM_BRCMSTB_AVS_CPUFREQ_DEBUG
+
+#define MANT(x) (unsigned int)(abs((x)) / 1000)
+#define FRAC(x) (unsigned int)(abs((x)) - abs((x)) / 1000 * 1000)
+
+static int brcm_avs_debug_show(struct seq_file *s, void *data)
+{
+ struct debugfs_data *dbgfs = s->private;
+ void __iomem *base;
+ u32 val, offset;
+
+ if (!dbgfs) {
+ seq_puts(s, "No device pointer\n");
+ return 0;
+ }
+
+ base = dbgfs->priv->base;
+ offset = dbgfs->entry->offset;
+ val = readl(base + offset);
+ switch (dbgfs->entry->format) {
+ case DEBUGFS_NORMAL:
+ seq_printf(s, "%u\n", val);
+ break;
+ case DEBUGFS_FLOAT:
+ seq_printf(s, "%d.%03d\n", MANT(val), FRAC(val));
+ break;
+ case DEBUGFS_REV:
+ seq_printf(s, "%c.%c.%c.%c\n", (val >> 24 & 0xff),
+ (val >> 16 & 0xff), (val >> 8 & 0xff),
+ val & 0xff);
+ break;
+ }
+ seq_printf(s, "0x%08x\n", val);
+
+ return 0;
+}
+
+#undef MANT
+#undef FRAC
+
+static ssize_t brcm_avs_seq_write(struct file *file, const char __user *buf,
+ size_t size, loff_t *ppos)
+{
+ struct seq_file *s = file->private_data;
+ struct debugfs_data *dbgfs = s->private;
+ struct private_data *priv = dbgfs->priv;
+ void __iomem *base, *avs_intr_base;
+ bool use_issue_command = false;
+ unsigned long val, offset;
+ char str[128];
+ int ret;
+ char *str_ptr = str;
+
+ if (size >= sizeof(str))
+ return -E2BIG;
+
+ memset(str, 0, sizeof(str));
+ ret = copy_from_user(str, buf, size);
+ if (ret)
+ return ret;
+
+ base = priv->base;
+ avs_intr_base = priv->avs_intr_base;
+ offset = dbgfs->entry->offset;
+ /*
+ * Special case writing to "command" entry only: if the string starts
+ * with a 'c', we use the driver's __issue_avs_command() function.
+ * Otherwise, we perform a raw write. This should allow testing of raw
+ * access as well as using the higher level function. (Raw access
+ * doesn't clear the firmware return status after issuing the command.)
+ */
+ if (str_ptr[0] == 'c' && offset == AVS_MBOX_COMMAND) {
+ use_issue_command = true;
+ str_ptr++;
+ }
+ if (kstrtoul(str_ptr, 0, &val) != 0)
+ return -EINVAL;
+
+ /*
+ * Setting the P-state is a special case. We need to update the CPU
+ * frequency we report.
+ */
+ if (val == AVS_CMD_SET_PSTATE) {
+ struct cpufreq_policy *policy;
+ unsigned int pstate;
+
+ policy = cpufreq_cpu_get(smp_processor_id());
+ /* Read back the P-state we are about to set */
+ pstate = readl(base + AVS_MBOX_PARAM(0));
+ if (use_issue_command) {
+ ret = brcm_avs_target_index(policy, pstate);
+ return ret ? ret : size;
+ }
+ policy->cur = policy->freq_table[pstate].frequency;
+ }
+
+ if (use_issue_command) {
+ ret = __issue_avs_command(priv, val, false, NULL);
+ } else {
+ /* Locking here is not perfect, but is only for debug. */
+ ret = down_interruptible(&priv->sem);
+ if (ret)
+ return ret;
+
+ writel(val, base + offset);
+ /* We have to wake up the firmware to process a command. */
+ if (offset == AVS_MBOX_COMMAND)
+ writel(AVS_CPU_L2_INT_MASK,
+ avs_intr_base + AVS_CPU_L2_SET0);
+ up(&priv->sem);
+ }
+
+ return ret ? ret : size;
+}
+
+static struct debugfs_entry *__find_debugfs_entry(const char *name)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(debugfs_entries); i++)
+ if (strcasecmp(debugfs_entries[i].name, name) == 0)
+ return &debugfs_entries[i];
+
+ return NULL;
+}
+
+static int brcm_avs_debug_open(struct inode *inode, struct file *file)
+{
+ struct debugfs_data *data;
+ fmode_t fmode;
+ int ret;
+
+ /*
+ * seq_open(), which is called by single_open(), clears "write" access.
+ * We need write access to some files, so we preserve our access mode
+ * and restore it.
+ */
+ fmode = file->f_mode;
+ /*
+ * Check access permissions even for root. We don't want to be writing
+ * to read-only registers. Access for regular users has already been
+ * checked by the VFS layer.
+ */
+ if ((fmode & FMODE_WRITER) && !(inode->i_mode & S_IWUSR))
+ return -EACCES;
+
+ data = kmalloc(sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+ /*
+ * We use the same file system operations for all our debug files. To
+ * produce specific output, we look up the file name upon opening a
+ * debugfs entry and map it to a memory offset. This offset is then used
+ * in the generic "show" function to read a specific register.
+ */
+ data->entry = __find_debugfs_entry(file->f_path.dentry->d_iname);
+ data->priv = inode->i_private;
+
+ ret = single_open(file, brcm_avs_debug_show, data);
+ if (ret)
+ kfree(data);
+ file->f_mode = fmode;
+
+ return ret;
+}
+
+static int brcm_avs_debug_release(struct inode *inode, struct file *file)
+{
+ struct seq_file *seq_priv = file->private_data;
+ struct debugfs_data *data = seq_priv->private;
+
+ kfree(data);
+ return single_release(inode, file);
+}
+
+static const struct file_operations brcm_avs_debug_ops = {
+ .open = brcm_avs_debug_open,
+ .read = seq_read,
+ .write = brcm_avs_seq_write,
+ .llseek = seq_lseek,
+ .release = brcm_avs_debug_release,
+};
+
+static void brcm_avs_cpufreq_debug_init(struct platform_device *pdev)
+{
+ struct private_data *priv = platform_get_drvdata(pdev);
+ struct dentry *dir;
+ int i;
+
+ if (!priv)
+ return;
+
+ dir = debugfs_create_dir(BRCM_AVS_CPUFREQ_NAME, NULL);
+ if (IS_ERR_OR_NULL(dir))
+ return;
+ priv->debugfs = dir;
+
+ for (i = 0; i < ARRAY_SIZE(debugfs_entries); i++) {
+ /*
+ * The DEBUGFS_ENTRY macro generates uppercase strings. We
+ * convert them to lowercase before creating the debugfs
+ * entries.
+ */
+ char *entry = __strtolower(debugfs_entries[i].name);
+ fmode_t mode = debugfs_entries[i].mode;
+
+ if (!debugfs_create_file(entry, S_IFREG | S_IRUGO | mode,
+ dir, priv, &brcm_avs_debug_ops)) {
+ priv->debugfs = NULL;
+ debugfs_remove_recursive(dir);
+ break;
+ }
+ }
+}
+
+static void brcm_avs_cpufreq_debug_exit(struct platform_device *pdev)
+{
+ struct private_data *priv = platform_get_drvdata(pdev);
+
+ if (priv && priv->debugfs) {
+ debugfs_remove_recursive(priv->debugfs);
+ priv->debugfs = NULL;
+ }
+}
+
+#else
+
+static void brcm_avs_cpufreq_debug_init(struct platform_device *pdev) {}
+static void brcm_avs_cpufreq_debug_exit(struct platform_device *pdev) {}
+
+#endif /* CONFIG_ARM_BRCMSTB_AVS_CPUFREQ_DEBUG */
+
+/*
+ * 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;
+
+ 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;
+
+ return brcm_avs_get_pmap(priv, &priv->pmap);
+}
+
+static int brcm_avs_resume(struct cpufreq_policy *policy)
+{
+ struct private_data *priv = policy->driver_data;
+ int ret;
+
+ 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 host_irq, 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;
+ }
+
+ host_irq = platform_get_irq_byname(pdev, BRCM_AVS_HOST_INTR);
+ if (host_irq < 0) {
+ dev_err(dev, "Couldn't find interrupt %s -- %d\n",
+ BRCM_AVS_HOST_INTR, host_irq);
+ ret = host_irq;
+ goto unmap_intr_base;
+ }
+
+ ret = devm_request_irq(dev, host_irq, irq_handler, IRQF_TRIGGER_RISING,
+ BRCM_AVS_HOST_INTR, priv);
+ if (ret) {
+ dev_err(dev, "IRQ request failed: %s (%d) -- %d\n",
+ BRCM_AVS_HOST_INTR, 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);
+ platform_set_drvdata(pdev, NULL);
+
+ return ret;
+}
+
+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;
+ }
+
+ ret = cpufreq_table_validate_and_show(policy, freq_table);
+ if (ret) {
+ dev_err(dev, "invalid frequency table: %d\n", ret);
+ return ret;
+ }
+
+ /* All cores share the same clock and thus the same policy. */
+ cpumask_setall(policy->cpus);
+
+ ret = __issue_avs_command(priv, AVS_CMD_ENABLE, false, 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\n",
+ pmap.p1, pmap.p2, ndiv, pdiv, mdiv_p0, mdiv_p1, mdiv_p2,
+ mdiv_p3, mdiv_p4);
+}
+
+static ssize_t show_brcm_avs_voltage(struct cpufreq_policy *policy, char *buf)
+{
+ struct private_data *priv = policy->driver_data;
+
+ return sprintf(buf, "0x%08lx\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%08lx\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_cpufreq_debug_init(pdev);
+
+ return ret;
+}
+
+static int brcm_avs_cpufreq_remove(struct platform_device *pdev)
+{
+ struct private_data *priv;
+ int ret;
+
+ ret = cpufreq_unregister_driver(&brcm_avs_driver);
+ if (ret)
+ return ret;
+
+ brcm_avs_cpufreq_debug_exit(pdev);
+
+ priv = platform_get_drvdata(pdev);
+ iounmap(priv->base);
+ iounmap(priv->avs_intr_base);
+ platform_set_drvdata(pdev, NULL);
+
+ return 0;
+}
+
+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 = 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");