new file mode 100644
@@ -0,0 +1,1085 @@
+/*
+ * System Control and Power Interface (SCPI) Message Protocol driver
+ *
+ * SCPI Message Protocol is used between the System Control Processor(SCP)
+ * and the Application Processors(AP). The Message Handling Unit(MHU)
+ * provides a mechanism for inter-processor communication between SCP's
+ * Cortex M3 and AP.
+ *
+ * SCP offers control and management of the core/cluster power states,
+ * various power domain DVFS including the core/cluster, certain system
+ * clocks configuration, thermal sensors and many others.
+ *
+ * Copyright (C) 2015 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/bitmap.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/export.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/mailbox_client.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/printk.h>
+#include <linux/pm_opp.h>
+#include <linux/scpi_protocol.h>
+#include <linux/slab.h>
+#include <linux/sort.h>
+#include <linux/spinlock.h>
+
+#define CMD_ID_SHIFT 0
+#define CMD_ID_MASK 0x7f
+#define CMD_TOKEN_ID_SHIFT 8
+#define CMD_TOKEN_ID_MASK 0xff
+#define CMD_DATA_SIZE_SHIFT 16
+#define CMD_DATA_SIZE_MASK 0x1ff
+#define CMD_LEGACY_DATA_SIZE_SHIFT 20
+#define CMD_LEGACY_DATA_SIZE_MASK 0x1ff
+#define PACK_SCPI_CMD(cmd_id, tx_sz) \
+ ((((cmd_id) & CMD_ID_MASK) << CMD_ID_SHIFT) | \
+ (((tx_sz) & CMD_DATA_SIZE_MASK) << CMD_DATA_SIZE_SHIFT))
+#define ADD_SCPI_TOKEN(cmd, token) \
+ ((cmd) |= (((token) & CMD_TOKEN_ID_MASK) << CMD_TOKEN_ID_SHIFT))
+#define PACK_LEGACY_SCPI_CMD(cmd_id, tx_sz) \
+ ((((cmd_id) & CMD_ID_MASK) << CMD_ID_SHIFT) | \
+ (((tx_sz) & CMD_LEGACY_DATA_SIZE_MASK) << CMD_LEGACY_DATA_SIZE_SHIFT))
+
+#define CMD_SIZE(cmd) (((cmd) >> CMD_DATA_SIZE_SHIFT) & CMD_DATA_SIZE_MASK)
+#define CMD_LEGACY_SIZE(cmd) (((cmd) >> CMD_LEGACY_DATA_SIZE_SHIFT) & \
+ CMD_LEGACY_DATA_SIZE_MASK)
+#define CMD_UNIQ_MASK (CMD_TOKEN_ID_MASK << CMD_TOKEN_ID_SHIFT | CMD_ID_MASK)
+#define CMD_XTRACT_UNIQ(cmd) ((cmd) & CMD_UNIQ_MASK)
+
+#define SCPI_SLOT 0
+
+#define MAX_DVFS_DOMAINS 8
+#define MAX_DVFS_OPPS 16
+#define DVFS_LATENCY(hdr) (le32_to_cpu(hdr) >> 16)
+#define DVFS_OPP_COUNT(hdr) ((le32_to_cpu(hdr) >> 8) & 0xff)
+
+#define PROTOCOL_REV_MINOR_BITS 16
+#define PROTOCOL_REV_MINOR_MASK ((1U << PROTOCOL_REV_MINOR_BITS) - 1)
+#define PROTOCOL_REV_MAJOR(x) ((x) >> PROTOCOL_REV_MINOR_BITS)
+#define PROTOCOL_REV_MINOR(x) ((x) & PROTOCOL_REV_MINOR_MASK)
+
+#define FW_REV_MAJOR_BITS 24
+#define FW_REV_MINOR_BITS 16
+#define FW_REV_PATCH_MASK ((1U << FW_REV_MINOR_BITS) - 1)
+#define FW_REV_MINOR_MASK ((1U << FW_REV_MAJOR_BITS) - 1)
+#define FW_REV_MAJOR(x) ((x) >> FW_REV_MAJOR_BITS)
+#define FW_REV_MINOR(x) (((x) & FW_REV_MINOR_MASK) >> FW_REV_MINOR_BITS)
+#define FW_REV_PATCH(x) ((x) & FW_REV_PATCH_MASK)
+
+#define MAX_RX_TIMEOUT (msecs_to_jiffies(30))
+
+enum scpi_error_codes {
+ SCPI_SUCCESS = 0, /* Success */
+ SCPI_ERR_PARAM = 1, /* Invalid parameter(s) */
+ SCPI_ERR_ALIGN = 2, /* Invalid alignment */
+ SCPI_ERR_SIZE = 3, /* Invalid size */
+ SCPI_ERR_HANDLER = 4, /* Invalid handler/callback */
+ SCPI_ERR_ACCESS = 5, /* Invalid access/permission denied */
+ SCPI_ERR_RANGE = 6, /* Value out of range */
+ SCPI_ERR_TIMEOUT = 7, /* Timeout has occurred */
+ SCPI_ERR_NOMEM = 8, /* Invalid memory area or pointer */
+ SCPI_ERR_PWRSTATE = 9, /* Invalid power state */
+ SCPI_ERR_SUPPORT = 10, /* Not supported or disabled */
+ SCPI_ERR_DEVICE = 11, /* Device error */
+ SCPI_ERR_BUSY = 12, /* Device busy */
+ SCPI_ERR_MAX
+};
+
+/* SCPI Standard commands */
+enum scpi_std_cmd {
+ SCPI_CMD_INVALID = 0x00,
+ SCPI_CMD_SCPI_READY = 0x01,
+ SCPI_CMD_SCPI_CAPABILITIES = 0x02,
+ SCPI_CMD_SET_CSS_PWR_STATE = 0x03,
+ SCPI_CMD_GET_CSS_PWR_STATE = 0x04,
+ SCPI_CMD_SET_SYS_PWR_STATE = 0x05,
+ SCPI_CMD_SET_CPU_TIMER = 0x06,
+ SCPI_CMD_CANCEL_CPU_TIMER = 0x07,
+ SCPI_CMD_DVFS_CAPABILITIES = 0x08,
+ SCPI_CMD_GET_DVFS_INFO = 0x09,
+ SCPI_CMD_SET_DVFS = 0x0a,
+ SCPI_CMD_GET_DVFS = 0x0b,
+ SCPI_CMD_GET_DVFS_STAT = 0x0c,
+ SCPI_CMD_CLOCK_CAPABILITIES = 0x0d,
+ SCPI_CMD_GET_CLOCK_INFO = 0x0e,
+ SCPI_CMD_SET_CLOCK_VALUE = 0x0f,
+ SCPI_CMD_GET_CLOCK_VALUE = 0x10,
+ SCPI_CMD_PSU_CAPABILITIES = 0x11,
+ SCPI_CMD_GET_PSU_INFO = 0x12,
+ SCPI_CMD_SET_PSU = 0x13,
+ SCPI_CMD_GET_PSU = 0x14,
+ SCPI_CMD_SENSOR_CAPABILITIES = 0x15,
+ SCPI_CMD_SENSOR_INFO = 0x16,
+ SCPI_CMD_SENSOR_VALUE = 0x17,
+ SCPI_CMD_SENSOR_CFG_PERIODIC = 0x18,
+ SCPI_CMD_SENSOR_CFG_BOUNDS = 0x19,
+ SCPI_CMD_SENSOR_ASYNC_VALUE = 0x1a,
+ SCPI_CMD_SET_DEVICE_PWR_STATE = 0x1b,
+ SCPI_CMD_GET_DEVICE_PWR_STATE = 0x1c,
+ SCPI_CMD_COUNT
+};
+
+/* SCPI Legacy Commands */
+enum legacy_scpi_std_cmd {
+ LEGACY_SCPI_CMD_INVALID = 0x00,
+ LEGACY_SCPI_CMD_SCPI_READY = 0x01,
+ LEGACY_SCPI_CMD_SCPI_CAPABILITIES = 0x02,
+ LEGACY_SCPI_CMD_EVENT = 0x03,
+ LEGACY_SCPI_CMD_SET_CSS_PWR_STATE = 0x04,
+ LEGACY_SCPI_CMD_GET_CSS_PWR_STATE = 0x05,
+ LEGACY_SCPI_CMD_CFG_PWR_STATE_STAT = 0x06,
+ LEGACY_SCPI_CMD_GET_PWR_STATE_STAT = 0x07,
+ LEGACY_SCPI_CMD_SYS_PWR_STATE = 0x08,
+ LEGACY_SCPI_CMD_L2_READY = 0x09,
+ LEGACY_SCPI_CMD_SET_AP_TIMER = 0x0a,
+ LEGACY_SCPI_CMD_CANCEL_AP_TIME = 0x0b,
+ LEGACY_SCPI_CMD_DVFS_CAPABILITIES = 0x0c,
+ LEGACY_SCPI_CMD_GET_DVFS_INFO = 0x0d,
+ LEGACY_SCPI_CMD_SET_DVFS = 0x0e,
+ LEGACY_SCPI_CMD_GET_DVFS = 0x0f,
+ LEGACY_SCPI_CMD_GET_DVFS_STAT = 0x10,
+ LEGACY_SCPI_CMD_SET_RTC = 0x11,
+ LEGACY_SCPI_CMD_GET_RTC = 0x12,
+ LEGACY_SCPI_CMD_CLOCK_CAPABILITIES = 0x13,
+ LEGACY_SCPI_CMD_SET_CLOCK_INDEX = 0x14,
+ LEGACY_SCPI_CMD_SET_CLOCK_VALUE = 0x15,
+ LEGACY_SCPI_CMD_GET_CLOCK_VALUE = 0x16,
+ LEGACY_SCPI_CMD_PSU_CAPABILITIES = 0x17,
+ LEGACY_SCPI_CMD_SET_PSU = 0x18,
+ LEGACY_SCPI_CMD_GET_PSU = 0x19,
+ LEGACY_SCPI_CMD_SENSOR_CAPABILITIES = 0x1a,
+ LEGACY_SCPI_CMD_SENSOR_INFO = 0x1b,
+ LEGACY_SCPI_CMD_SENSOR_VALUE = 0x1c,
+ LEGACY_SCPI_CMD_SENSOR_CFG_PERIODIC = 0x1d,
+ LEGACY_SCPI_CMD_SENSOR_CFG_BOUNDS = 0x1e,
+ LEGACY_SCPI_CMD_SENSOR_ASYNC_VALUE = 0x1f,
+ LEGACY_SCPI_CMD_COUNT
+};
+
+/* List all commands that are required to go through the high priority link */
+static int legacy_hpriority_cmds[] = {
+ LEGACY_SCPI_CMD_GET_CSS_PWR_STATE,
+ LEGACY_SCPI_CMD_CFG_PWR_STATE_STAT,
+ LEGACY_SCPI_CMD_GET_PWR_STATE_STAT,
+ LEGACY_SCPI_CMD_SET_DVFS,
+ LEGACY_SCPI_CMD_GET_DVFS,
+ LEGACY_SCPI_CMD_SET_RTC,
+ LEGACY_SCPI_CMD_GET_RTC,
+ LEGACY_SCPI_CMD_SET_CLOCK_INDEX,
+ LEGACY_SCPI_CMD_SET_CLOCK_VALUE,
+ LEGACY_SCPI_CMD_GET_CLOCK_VALUE,
+ LEGACY_SCPI_CMD_SET_PSU,
+ LEGACY_SCPI_CMD_GET_PSU,
+ LEGACY_SCPI_CMD_SENSOR_CFG_PERIODIC,
+ LEGACY_SCPI_CMD_SENSOR_CFG_BOUNDS,
+};
+
+/* List all commands used by this driver, used as indexes */
+enum scpi_drv_cmds {
+ CMD_SCPI_CAPABILITIES = 0,
+ CMD_GET_CLOCK_INFO,
+ CMD_GET_CLOCK_VALUE,
+ CMD_SET_CLOCK_VALUE,
+ CMD_GET_DVFS,
+ CMD_SET_DVFS,
+ CMD_GET_DVFS_INFO,
+ CMD_SENSOR_CAPABILITIES,
+ CMD_SENSOR_INFO,
+ CMD_SENSOR_VALUE,
+ CMD_SET_DEVICE_PWR_STATE,
+ CMD_GET_DEVICE_PWR_STATE,
+ CMD_MAX_COUNT,
+};
+
+static int scpi_std_commands[CMD_MAX_COUNT] = {
+ SCPI_CMD_SCPI_CAPABILITIES,
+ SCPI_CMD_GET_CLOCK_INFO,
+ SCPI_CMD_GET_CLOCK_VALUE,
+ SCPI_CMD_SET_CLOCK_VALUE,
+ SCPI_CMD_GET_DVFS,
+ SCPI_CMD_SET_DVFS,
+ SCPI_CMD_GET_DVFS_INFO,
+ SCPI_CMD_SENSOR_CAPABILITIES,
+ SCPI_CMD_SENSOR_INFO,
+ SCPI_CMD_SENSOR_VALUE,
+ SCPI_CMD_SET_DEVICE_PWR_STATE,
+ SCPI_CMD_GET_DEVICE_PWR_STATE,
+};
+
+static int scpi_legacy_commands[CMD_MAX_COUNT] = {
+ LEGACY_SCPI_CMD_SCPI_CAPABILITIES,
+ -1, /* GET_CLOCK_INFO */
+ LEGACY_SCPI_CMD_GET_CLOCK_VALUE,
+ LEGACY_SCPI_CMD_SET_CLOCK_VALUE,
+ LEGACY_SCPI_CMD_GET_DVFS,
+ LEGACY_SCPI_CMD_SET_DVFS,
+ LEGACY_SCPI_CMD_GET_DVFS_INFO,
+ LEGACY_SCPI_CMD_SENSOR_CAPABILITIES,
+ LEGACY_SCPI_CMD_SENSOR_INFO,
+ LEGACY_SCPI_CMD_SENSOR_VALUE,
+ -1, /* SET_DEVICE_PWR_STATE */
+ -1, /* GET_DEVICE_PWR_STATE */
+};
+
+struct scpi_xfer {
+ u32 slot; /* has to be first element */
+ u32 cmd;
+ u32 status;
+ const void *tx_buf;
+ void *rx_buf;
+ unsigned int tx_len;
+ unsigned int rx_len;
+ struct list_head node;
+ struct completion done;
+};
+
+struct scpi_chan {
+ struct mbox_client cl;
+ struct mbox_chan *chan;
+ void __iomem *tx_payload;
+ void __iomem *rx_payload;
+ struct list_head rx_pending;
+ struct list_head xfers_list;
+ struct scpi_xfer *xfers;
+ spinlock_t rx_lock; /* locking for the rx pending list */
+ struct mutex xfers_lock;
+ u8 token;
+};
+
+struct scpi_drvinfo {
+ u32 protocol_version;
+ u32 firmware_version;
+ bool is_legacy;
+ int num_chans;
+ int *commands;
+ DECLARE_BITMAP(cmd_priority, LEGACY_SCPI_CMD_COUNT);
+ atomic_t next_chan;
+ struct scpi_ops *scpi_ops;
+ struct scpi_chan *channels;
+ struct scpi_dvfs_info *dvfs[MAX_DVFS_DOMAINS];
+};
+
+/*
+ * The SCP firmware only executes in little-endian mode, so any buffers
+ * shared through SCPI should have their contents converted to little-endian
+ */
+struct scpi_shared_mem {
+ __le32 command;
+ __le32 status;
+ u8 payload[0];
+} __packed;
+
+struct legacy_scpi_shared_mem {
+ __le32 status;
+ u8 payload[0];
+} __packed;
+
+struct scp_capabilities {
+ __le32 protocol_version;
+ __le32 event_version;
+ __le32 platform_version;
+ __le32 commands[4];
+} __packed;
+
+struct clk_get_info {
+ __le16 id;
+ __le16 flags;
+ __le32 min_rate;
+ __le32 max_rate;
+ u8 name[20];
+} __packed;
+
+struct clk_get_value {
+ __le32 rate;
+} __packed;
+
+struct clk_set_value {
+ __le16 id;
+ __le16 reserved;
+ __le32 rate;
+} __packed;
+
+struct legacy_clk_set_value {
+ __le32 rate;
+ __le16 id;
+ __le16 reserved;
+} __packed;
+
+struct dvfs_info {
+ __le32 header;
+ struct {
+ __le32 freq;
+ __le32 m_volt;
+ } opps[MAX_DVFS_OPPS];
+} __packed;
+
+struct dvfs_set {
+ u8 domain;
+ u8 index;
+} __packed;
+
+struct sensor_capabilities {
+ __le16 sensors;
+} __packed;
+
+struct _scpi_sensor_info {
+ __le16 sensor_id;
+ u8 class;
+ u8 trigger_type;
+ char name[20];
+};
+
+struct sensor_value {
+ __le32 lo_val;
+ __le32 hi_val;
+} __packed;
+
+struct dev_pstate_set {
+ __le16 dev_id;
+ u8 pstate;
+} __packed;
+
+static struct scpi_drvinfo *scpi_info;
+
+static int scpi_linux_errmap[SCPI_ERR_MAX] = {
+ /* better than switch case as long as return value is continuous */
+ 0, /* SCPI_SUCCESS */
+ -EINVAL, /* SCPI_ERR_PARAM */
+ -ENOEXEC, /* SCPI_ERR_ALIGN */
+ -EMSGSIZE, /* SCPI_ERR_SIZE */
+ -EINVAL, /* SCPI_ERR_HANDLER */
+ -EACCES, /* SCPI_ERR_ACCESS */
+ -ERANGE, /* SCPI_ERR_RANGE */
+ -ETIMEDOUT, /* SCPI_ERR_TIMEOUT */
+ -ENOMEM, /* SCPI_ERR_NOMEM */
+ -EINVAL, /* SCPI_ERR_PWRSTATE */
+ -EOPNOTSUPP, /* SCPI_ERR_SUPPORT */
+ -EIO, /* SCPI_ERR_DEVICE */
+ -EBUSY, /* SCPI_ERR_BUSY */
+};
+
+static inline int scpi_to_linux_errno(int errno)
+{
+ if (errno >= SCPI_SUCCESS && errno < SCPI_ERR_MAX)
+ return scpi_linux_errmap[errno];
+ return -EIO;
+}
+
+static void scpi_process_cmd(struct scpi_chan *ch, u32 cmd)
+{
+ unsigned long flags;
+ struct scpi_xfer *t, *match = NULL;
+
+ spin_lock_irqsave(&ch->rx_lock, flags);
+ if (list_empty(&ch->rx_pending)) {
+ spin_unlock_irqrestore(&ch->rx_lock, flags);
+ return;
+ }
+
+ /* Command type is not replied by the SCP Firmware in legacy Mode
+ * We should consider that command is the head of pending RX commands
+ * if the list is not empty. In TX only mode, the list would be empty.
+ */
+ if (scpi_info->is_legacy) {
+ match = list_first_entry(&ch->rx_pending, struct scpi_xfer,
+ node);
+ list_del(&match->node);
+ } else {
+ list_for_each_entry(t, &ch->rx_pending, node)
+ if (CMD_XTRACT_UNIQ(t->cmd) == CMD_XTRACT_UNIQ(cmd)) {
+ list_del(&t->node);
+ match = t;
+ break;
+ }
+ }
+ /* check if wait_for_completion is in progress or timed-out */
+ if (match && !completion_done(&match->done)) {
+ unsigned int len;
+
+ if (scpi_info->is_legacy) {
+ struct legacy_scpi_shared_mem *mem = ch->rx_payload;
+
+ /* RX Length is not replied by the legacy Firmware */
+ len = match->rx_len;
+
+ match->status = le32_to_cpu(mem->status);
+ memcpy_fromio(match->rx_buf, mem->payload, len);
+ } else {
+ struct scpi_shared_mem *mem = ch->rx_payload;
+
+ len = min(match->rx_len, CMD_SIZE(cmd));
+
+ match->status = le32_to_cpu(mem->status);
+ memcpy_fromio(match->rx_buf, mem->payload, len);
+ }
+
+ if (match->rx_len > len)
+ memset(match->rx_buf + len, 0, match->rx_len - len);
+ complete(&match->done);
+ }
+ spin_unlock_irqrestore(&ch->rx_lock, flags);
+}
+
+static void scpi_handle_remote_msg(struct mbox_client *c, void *msg)
+{
+ struct scpi_chan *ch = container_of(c, struct scpi_chan, cl);
+ struct scpi_shared_mem *mem = ch->rx_payload;
+ u32 cmd = 0;
+
+ if (!scpi_info->is_legacy)
+ cmd = le32_to_cpu(mem->command);
+
+ scpi_process_cmd(ch, cmd);
+}
+
+static void scpi_tx_prepare(struct mbox_client *c, void *msg)
+{
+ unsigned long flags;
+ struct scpi_xfer *t = msg;
+ struct scpi_chan *ch = container_of(c, struct scpi_chan, cl);
+ struct scpi_shared_mem *mem = (struct scpi_shared_mem *)ch->tx_payload;
+
+ if (t->tx_buf) {
+ if (scpi_info->is_legacy)
+ memcpy_toio(ch->tx_payload, t->tx_buf, t->tx_len);
+ else
+ memcpy_toio(mem->payload, t->tx_buf, t->tx_len);
+ }
+
+ if (t->rx_buf) {
+ if (!(++ch->token))
+ ++ch->token;
+ ADD_SCPI_TOKEN(t->cmd, ch->token);
+ spin_lock_irqsave(&ch->rx_lock, flags);
+ list_add_tail(&t->node, &ch->rx_pending);
+ spin_unlock_irqrestore(&ch->rx_lock, flags);
+ }
+
+ if (!scpi_info->is_legacy)
+ mem->command = cpu_to_le32(t->cmd);
+}
+
+static struct scpi_xfer *get_scpi_xfer(struct scpi_chan *ch)
+{
+ struct scpi_xfer *t;
+
+ mutex_lock(&ch->xfers_lock);
+ if (list_empty(&ch->xfers_list)) {
+ mutex_unlock(&ch->xfers_lock);
+ return NULL;
+ }
+ t = list_first_entry(&ch->xfers_list, struct scpi_xfer, node);
+ list_del(&t->node);
+ mutex_unlock(&ch->xfers_lock);
+ return t;
+}
+
+static void put_scpi_xfer(struct scpi_xfer *t, struct scpi_chan *ch)
+{
+ mutex_lock(&ch->xfers_lock);
+ list_add_tail(&t->node, &ch->xfers_list);
+ mutex_unlock(&ch->xfers_lock);
+}
+
+static int scpi_send_message(u8 idx, void *tx_buf, unsigned int tx_len,
+ void *rx_buf, unsigned int rx_len)
+{
+ int ret;
+ u8 chan;
+ u8 cmd;
+ struct scpi_xfer *msg;
+ struct scpi_chan *scpi_chan;
+
+ if (scpi_info->commands[idx] < 0)
+ return -EOPNOTSUPP;
+
+ cmd = scpi_info->commands[idx];
+
+ if (scpi_info->is_legacy)
+ chan = test_bit(cmd, scpi_info->cmd_priority) ? 1 : 0;
+ else
+ chan = atomic_inc_return(&scpi_info->next_chan) %
+ scpi_info->num_chans;
+ scpi_chan = scpi_info->channels + chan;
+
+ msg = get_scpi_xfer(scpi_chan);
+ if (!msg)
+ return -ENOMEM;
+
+ if (scpi_info->is_legacy) {
+ msg->cmd = PACK_LEGACY_SCPI_CMD(cmd, tx_len);
+ msg->slot = msg->cmd;
+ } else {
+ msg->slot = BIT(SCPI_SLOT);
+ msg->cmd = PACK_SCPI_CMD(cmd, tx_len);
+ }
+ msg->tx_buf = tx_buf;
+ msg->tx_len = tx_len;
+ msg->rx_buf = rx_buf;
+ msg->rx_len = rx_len;
+ reinit_completion(&msg->done);
+
+ ret = mbox_send_message(scpi_chan->chan, msg);
+ if (ret < 0 || !rx_buf)
+ goto out;
+
+ if (!wait_for_completion_timeout(&msg->done, MAX_RX_TIMEOUT))
+ ret = -ETIMEDOUT;
+ else
+ /* first status word */
+ ret = msg->status;
+out:
+ if (ret < 0 && rx_buf) /* remove entry from the list if timed-out */
+ scpi_process_cmd(scpi_chan, msg->cmd);
+
+ put_scpi_xfer(msg, scpi_chan);
+ /* SCPI error codes > 0, translate them to Linux scale*/
+ return ret > 0 ? scpi_to_linux_errno(ret) : ret;
+}
+
+static u32 scpi_get_version(void)
+{
+ return scpi_info->protocol_version;
+}
+
+static int
+scpi_clk_get_range(u16 clk_id, unsigned long *min, unsigned long *max)
+{
+ int ret;
+ struct clk_get_info clk;
+ __le16 le_clk_id = cpu_to_le16(clk_id);
+
+ ret = scpi_send_message(CMD_GET_CLOCK_INFO, &le_clk_id,
+ sizeof(le_clk_id), &clk, sizeof(clk));
+ if (!ret) {
+ *min = le32_to_cpu(clk.min_rate);
+ *max = le32_to_cpu(clk.max_rate);
+ }
+ return ret;
+}
+
+static unsigned long scpi_clk_get_val(u16 clk_id)
+{
+ int ret;
+ struct clk_get_value clk;
+ __le16 le_clk_id = cpu_to_le16(clk_id);
+
+ ret = scpi_send_message(CMD_GET_CLOCK_VALUE, &le_clk_id,
+ sizeof(le_clk_id), &clk, sizeof(clk));
+
+ return ret ? ret : le32_to_cpu(clk.rate);
+}
+
+static int scpi_clk_set_val(u16 clk_id, unsigned long rate)
+{
+ int stat;
+ struct clk_set_value clk = {
+ .id = cpu_to_le16(clk_id),
+ .rate = cpu_to_le32(rate)
+ };
+
+ return scpi_send_message(CMD_SET_CLOCK_VALUE, &clk, sizeof(clk),
+ &stat, sizeof(stat));
+}
+
+static int legacy_scpi_clk_set_val(u16 clk_id, unsigned long rate)
+{
+ int stat;
+ struct legacy_clk_set_value clk = {
+ .id = cpu_to_le16(clk_id),
+ .rate = cpu_to_le32(rate)
+ };
+
+ return scpi_send_message(CMD_SET_CLOCK_VALUE, &clk, sizeof(clk),
+ &stat, sizeof(stat));
+}
+
+static int scpi_dvfs_get_idx(u8 domain)
+{
+ int ret;
+ u8 dvfs_idx;
+
+ ret = scpi_send_message(CMD_GET_DVFS, &domain, sizeof(domain),
+ &dvfs_idx, sizeof(dvfs_idx));
+
+ return ret ? ret : dvfs_idx;
+}
+
+static int scpi_dvfs_set_idx(u8 domain, u8 index)
+{
+ int stat;
+ struct dvfs_set dvfs = {domain, index};
+
+ return scpi_send_message(CMD_SET_DVFS, &dvfs, sizeof(dvfs),
+ &stat, sizeof(stat));
+}
+
+static int opp_cmp_func(const void *opp1, const void *opp2)
+{
+ const struct scpi_opp *t1 = opp1, *t2 = opp2;
+
+ return t1->freq - t2->freq;
+}
+
+static struct scpi_dvfs_info *scpi_dvfs_get_info(u8 domain)
+{
+ struct scpi_dvfs_info *info;
+ struct scpi_opp *opp;
+ struct dvfs_info buf;
+ int ret, i;
+
+ if (domain >= MAX_DVFS_DOMAINS)
+ return ERR_PTR(-EINVAL);
+
+ if (scpi_info->dvfs[domain]) /* data already populated */
+ return scpi_info->dvfs[domain];
+
+ ret = scpi_send_message(CMD_GET_DVFS_INFO, &domain, sizeof(domain),
+ &buf, sizeof(buf));
+ if (ret)
+ return ERR_PTR(ret);
+
+ info = kmalloc(sizeof(*info), GFP_KERNEL);
+ if (!info)
+ return ERR_PTR(-ENOMEM);
+
+ info->count = DVFS_OPP_COUNT(buf.header);
+ info->latency = DVFS_LATENCY(buf.header) * 1000; /* uS to nS */
+
+ info->opps = kcalloc(info->count, sizeof(*opp), GFP_KERNEL);
+ if (!info->opps) {
+ kfree(info);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ for (i = 0, opp = info->opps; i < info->count; i++, opp++) {
+ opp->freq = le32_to_cpu(buf.opps[i].freq);
+ opp->m_volt = le32_to_cpu(buf.opps[i].m_volt);
+ }
+
+ sort(info->opps, info->count, sizeof(*opp), opp_cmp_func, NULL);
+
+ scpi_info->dvfs[domain] = info;
+ return info;
+}
+
+static int scpi_dev_domain_id(struct device *dev)
+{
+ struct of_phandle_args clkspec;
+
+ if (of_parse_phandle_with_args(dev->of_node, "clocks", "#clock-cells",
+ 0, &clkspec))
+ return -EINVAL;
+
+ return clkspec.args[0];
+}
+
+static struct scpi_dvfs_info *scpi_dvfs_info(struct device *dev)
+{
+ int domain = scpi_dev_domain_id(dev);
+
+ if (domain < 0)
+ return ERR_PTR(domain);
+
+ return scpi_dvfs_get_info(domain);
+}
+
+static int scpi_dvfs_get_transition_latency(struct device *dev)
+{
+ struct scpi_dvfs_info *info = scpi_dvfs_info(dev);
+
+ if (IS_ERR(info))
+ return PTR_ERR(info);
+
+ if (!info->latency)
+ return 0;
+
+ return info->latency;
+}
+
+static int scpi_dvfs_add_opps_to_device(struct device *dev)
+{
+ int idx, ret;
+ struct scpi_opp *opp;
+ struct scpi_dvfs_info *info = scpi_dvfs_info(dev);
+
+ if (IS_ERR(info))
+ return PTR_ERR(info);
+
+ if (!info->opps)
+ return -EIO;
+
+ for (opp = info->opps, idx = 0; idx < info->count; idx++, opp++) {
+ ret = dev_pm_opp_add(dev, opp->freq, opp->m_volt * 1000);
+ if (ret) {
+ dev_warn(dev, "failed to add opp %uHz %umV\n",
+ opp->freq, opp->m_volt);
+ while (idx-- > 0)
+ dev_pm_opp_remove(dev, (--opp)->freq);
+ return ret;
+ }
+ }
+ return 0;
+}
+
+static int scpi_sensor_get_capability(u16 *sensors)
+{
+ struct sensor_capabilities cap_buf;
+ int ret;
+
+ ret = scpi_send_message(CMD_SENSOR_CAPABILITIES, NULL, 0, &cap_buf,
+ sizeof(cap_buf));
+ if (!ret)
+ *sensors = le16_to_cpu(cap_buf.sensors);
+
+ return ret;
+}
+
+static int scpi_sensor_get_info(u16 sensor_id, struct scpi_sensor_info *info)
+{
+ __le16 id = cpu_to_le16(sensor_id);
+ struct _scpi_sensor_info _info;
+ int ret;
+
+ ret = scpi_send_message(CMD_SENSOR_INFO, &id, sizeof(id),
+ &_info, sizeof(_info));
+ if (!ret) {
+ memcpy(info, &_info, sizeof(*info));
+ info->sensor_id = le16_to_cpu(_info.sensor_id);
+ }
+
+ return ret;
+}
+
+static int scpi_sensor_get_value(u16 sensor, u64 *val)
+{
+ __le16 id = cpu_to_le16(sensor);
+ struct sensor_value buf;
+ int ret;
+
+ ret = scpi_send_message(CMD_SENSOR_VALUE, &id, sizeof(id),
+ &buf, sizeof(buf));
+ if (ret)
+ return ret;
+
+ if (scpi_info->is_legacy)
+ /* only 32-bits supported, hi_val can be junk */
+ *val = le32_to_cpu(buf.lo_val);
+ else
+ *val = (u64)le32_to_cpu(buf.hi_val) << 32 |
+ le32_to_cpu(buf.lo_val);
+
+ return 0;
+}
+
+static int scpi_device_get_power_state(u16 dev_id)
+{
+ int ret;
+ u8 pstate;
+ __le16 id = cpu_to_le16(dev_id);
+
+ ret = scpi_send_message(CMD_GET_DEVICE_PWR_STATE, &id,
+ sizeof(id), &pstate, sizeof(pstate));
+ return ret ? ret : pstate;
+}
+
+static int scpi_device_set_power_state(u16 dev_id, u8 pstate)
+{
+ int stat;
+ struct dev_pstate_set dev_set = {
+ .dev_id = cpu_to_le16(dev_id),
+ .pstate = pstate,
+ };
+
+ return scpi_send_message(CMD_SET_DEVICE_PWR_STATE, &dev_set,
+ sizeof(dev_set), &stat, sizeof(stat));
+}
+
+static struct scpi_ops scpi_ops = {
+ .get_version = scpi_get_version,
+ .clk_get_range = scpi_clk_get_range,
+ .clk_get_val = scpi_clk_get_val,
+ .clk_set_val = scpi_clk_set_val,
+ .dvfs_get_idx = scpi_dvfs_get_idx,
+ .dvfs_set_idx = scpi_dvfs_set_idx,
+ .dvfs_get_info = scpi_dvfs_get_info,
+ .device_domain_id = scpi_dev_domain_id,
+ .get_transition_latency = scpi_dvfs_get_transition_latency,
+ .add_opps_to_device = scpi_dvfs_add_opps_to_device,
+ .sensor_get_capability = scpi_sensor_get_capability,
+ .sensor_get_info = scpi_sensor_get_info,
+ .sensor_get_value = scpi_sensor_get_value,
+ .device_get_power_state = scpi_device_get_power_state,
+ .device_set_power_state = scpi_device_set_power_state,
+};
+
+struct scpi_ops *get_scpi_ops(void)
+{
+ return scpi_info ? scpi_info->scpi_ops : NULL;
+}
+EXPORT_SYMBOL_GPL(get_scpi_ops);
+
+static int scpi_init_versions(struct scpi_drvinfo *info)
+{
+ int ret;
+ struct scp_capabilities caps;
+
+ ret = scpi_send_message(CMD_SCPI_CAPABILITIES, NULL, 0,
+ &caps, sizeof(caps));
+ if (!ret) {
+ info->protocol_version = le32_to_cpu(caps.protocol_version);
+ info->firmware_version = le32_to_cpu(caps.platform_version);
+ }
+ /* Ignore error if not implemented */
+ if (scpi_info->is_legacy && ret == -EOPNOTSUPP)
+ return 0;
+
+ return ret;
+}
+
+static ssize_t protocol_version_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct scpi_drvinfo *scpi_info = dev_get_drvdata(dev);
+
+ return sprintf(buf, "%d.%d\n",
+ PROTOCOL_REV_MAJOR(scpi_info->protocol_version),
+ PROTOCOL_REV_MINOR(scpi_info->protocol_version));
+}
+static DEVICE_ATTR_RO(protocol_version);
+
+static ssize_t firmware_version_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct scpi_drvinfo *scpi_info = dev_get_drvdata(dev);
+
+ return sprintf(buf, "%d.%d.%d\n",
+ FW_REV_MAJOR(scpi_info->firmware_version),
+ FW_REV_MINOR(scpi_info->firmware_version),
+ FW_REV_PATCH(scpi_info->firmware_version));
+}
+static DEVICE_ATTR_RO(firmware_version);
+
+static struct attribute *versions_attrs[] = {
+ &dev_attr_firmware_version.attr,
+ &dev_attr_protocol_version.attr,
+ NULL,
+};
+ATTRIBUTE_GROUPS(versions);
+
+static void
+scpi_free_channels(struct device *dev, struct scpi_chan *pchan, int count)
+{
+ int i;
+
+ for (i = 0; i < count && pchan->chan; i++, pchan++) {
+ mbox_free_channel(pchan->chan);
+ devm_kfree(dev, pchan->xfers);
+ devm_iounmap(dev, pchan->rx_payload);
+ }
+}
+
+static int scpi_remove(struct platform_device *pdev)
+{
+ int i;
+ struct device *dev = &pdev->dev;
+ struct scpi_drvinfo *info = platform_get_drvdata(pdev);
+
+ scpi_info = NULL; /* stop exporting SCPI ops through get_scpi_ops */
+
+ of_platform_depopulate(dev);
+ sysfs_remove_groups(&dev->kobj, versions_groups);
+ scpi_free_channels(dev, info->channels, info->num_chans);
+ platform_set_drvdata(pdev, NULL);
+
+ for (i = 0; i < MAX_DVFS_DOMAINS && info->dvfs[i]; i++) {
+ kfree(info->dvfs[i]->opps);
+ kfree(info->dvfs[i]);
+ }
+ devm_kfree(dev, info->channels);
+ devm_kfree(dev, info);
+
+ return 0;
+}
+
+#define MAX_SCPI_XFERS 10
+static int scpi_alloc_xfer_list(struct device *dev, struct scpi_chan *ch)
+{
+ int i;
+ struct scpi_xfer *xfers;
+
+ xfers = devm_kzalloc(dev, MAX_SCPI_XFERS * sizeof(*xfers), GFP_KERNEL);
+ if (!xfers)
+ return -ENOMEM;
+
+ ch->xfers = xfers;
+ for (i = 0; i < MAX_SCPI_XFERS; i++, xfers++) {
+ init_completion(&xfers->done);
+ list_add_tail(&xfers->node, &ch->xfers_list);
+ }
+
+ return 0;
+}
+
+static const struct of_device_id legacy_scpi_of_match[] = {
+ {.compatible = "arm,scpi-pre-1.0"},
+ {},
+};
+
+static int scpi_probe(struct platform_device *pdev)
+{
+ int count, idx, ret;
+ struct resource res;
+ struct scpi_chan *scpi_chan;
+ struct device *dev = &pdev->dev;
+ struct device_node *np = dev->of_node;
+
+ scpi_info = devm_kzalloc(dev, sizeof(*scpi_info), GFP_KERNEL);
+ if (!scpi_info)
+ return -ENOMEM;
+
+ if (of_match_device(legacy_scpi_of_match, &pdev->dev))
+ scpi_info->is_legacy = true;
+
+ count = of_count_phandle_with_args(np, "mboxes", "#mbox-cells");
+ if (count < 0) {
+ dev_err(dev, "no mboxes property in '%pOF'\n", np);
+ return -ENODEV;
+ }
+
+ scpi_chan = devm_kcalloc(dev, count, sizeof(*scpi_chan), GFP_KERNEL);
+ if (!scpi_chan)
+ return -ENOMEM;
+
+ for (idx = 0; idx < count; idx++) {
+ resource_size_t size;
+ struct scpi_chan *pchan = scpi_chan + idx;
+ struct mbox_client *cl = &pchan->cl;
+ struct device_node *shmem = of_parse_phandle(np, "shmem", idx);
+
+ ret = of_address_to_resource(shmem, 0, &res);
+ of_node_put(shmem);
+ if (ret) {
+ dev_err(dev, "failed to get SCPI payload mem resource\n");
+ goto err;
+ }
+
+ size = resource_size(&res);
+ pchan->rx_payload = devm_ioremap(dev, res.start, size);
+ if (!pchan->rx_payload) {
+ dev_err(dev, "failed to ioremap SCPI payload\n");
+ ret = -EADDRNOTAVAIL;
+ goto err;
+ }
+ pchan->tx_payload = pchan->rx_payload + (size >> 1);
+
+ cl->dev = dev;
+ cl->rx_callback = scpi_handle_remote_msg;
+ cl->tx_prepare = scpi_tx_prepare;
+ cl->tx_block = true;
+ cl->tx_tout = 20;
+ cl->knows_txdone = false; /* controller can't ack */
+
+ INIT_LIST_HEAD(&pchan->rx_pending);
+ INIT_LIST_HEAD(&pchan->xfers_list);
+ spin_lock_init(&pchan->rx_lock);
+ mutex_init(&pchan->xfers_lock);
+
+ ret = scpi_alloc_xfer_list(dev, pchan);
+ if (!ret) {
+ pchan->chan = mbox_request_channel(cl, idx);
+ if (!IS_ERR(pchan->chan))
+ continue;
+ ret = PTR_ERR(pchan->chan);
+ if (ret != -EPROBE_DEFER)
+ dev_err(dev, "failed to get channel%d err %d\n",
+ idx, ret);
+ }
+err:
+ scpi_free_channels(dev, scpi_chan, idx);
+ scpi_info = NULL;
+ return ret;
+ }
+
+ scpi_info->channels = scpi_chan;
+ scpi_info->num_chans = count;
+ scpi_info->commands = scpi_std_commands;
+
+ platform_set_drvdata(pdev, scpi_info);
+
+ if (scpi_info->is_legacy) {
+ /* Replace with legacy variants */
+ scpi_ops.clk_set_val = legacy_scpi_clk_set_val;
+ scpi_info->commands = scpi_legacy_commands;
+
+ /* Fill priority bitmap */
+ for (idx = 0; idx < ARRAY_SIZE(legacy_hpriority_cmds); idx++)
+ set_bit(legacy_hpriority_cmds[idx],
+ scpi_info->cmd_priority);
+ }
+
+ ret = scpi_init_versions(scpi_info);
+ if (ret) {
+ dev_err(dev, "incorrect or no SCP firmware found\n");
+ scpi_remove(pdev);
+ return ret;
+ }
+
+ _dev_info(dev, "SCP Protocol %d.%d Firmware %d.%d.%d version\n",
+ PROTOCOL_REV_MAJOR(scpi_info->protocol_version),
+ PROTOCOL_REV_MINOR(scpi_info->protocol_version),
+ FW_REV_MAJOR(scpi_info->firmware_version),
+ FW_REV_MINOR(scpi_info->firmware_version),
+ FW_REV_PATCH(scpi_info->firmware_version));
+ scpi_info->scpi_ops = &scpi_ops;
+
+ ret = sysfs_create_groups(&dev->kobj, versions_groups);
+ if (ret)
+ dev_err(dev, "unable to create sysfs version group\n");
+
+ return of_platform_populate(dev->of_node, NULL, NULL, dev);
+}
+
+static const struct of_device_id scpi_of_match[] = {
+ {.compatible = "arm,scpi"},
+ {.compatible = "arm,scpi-pre-1.0"},
+ {},
+};
+
+MODULE_DEVICE_TABLE(of, scpi_of_match);
+
+static struct platform_driver scpi_driver = {
+ .driver = {
+ .name = "scpi_protocol",
+ .of_match_table = scpi_of_match,
+ },
+ .probe = scpi_probe,
+ .remove = scpi_remove,
+};
+module_platform_driver(scpi_driver);
+
+MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
+MODULE_DESCRIPTION("ARM SCPI mailbox protocol driver");
+MODULE_LICENSE("GPL v2");
new file mode 100644
@@ -0,0 +1,84 @@
+/*
+ * SCPI Message Protocol driver header
+ *
+ * Copyright (C) 2014 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <linux/types.h>
+
+struct scpi_opp {
+ u32 freq;
+ u32 m_volt;
+} __packed;
+
+struct scpi_dvfs_info {
+ unsigned int count;
+ unsigned int latency; /* in nanoseconds */
+ struct scpi_opp *opps;
+};
+
+enum scpi_sensor_class {
+ TEMPERATURE,
+ VOLTAGE,
+ CURRENT,
+ POWER,
+ ENERGY,
+};
+
+struct scpi_sensor_info {
+ u16 sensor_id;
+ u8 class;
+ u8 trigger_type;
+ char name[20];
+} __packed;
+
+/**
+ * struct scpi_ops - represents the various operations provided
+ * by SCP through SCPI message protocol
+ * @get_version: returns the major and minor revision on the SCPI
+ * message protocol
+ * @clk_get_range: gets clock range limit(min - max in Hz)
+ * @clk_get_val: gets clock value(in Hz)
+ * @clk_set_val: sets the clock value, setting to 0 will disable the
+ * clock (if supported)
+ * @dvfs_get_idx: gets the Operating Point of the given power domain.
+ * OPP is an index to the list return by @dvfs_get_info
+ * @dvfs_set_idx: sets the Operating Point of the given power domain.
+ * OPP is an index to the list return by @dvfs_get_info
+ * @dvfs_get_info: returns the DVFS capabilities of the given power
+ * domain. It includes the OPP list and the latency information
+ */
+struct scpi_ops {
+ u32 (*get_version)(void);
+ int (*clk_get_range)(u16, unsigned long *, unsigned long *);
+ unsigned long (*clk_get_val)(u16);
+ int (*clk_set_val)(u16, unsigned long);
+ int (*dvfs_get_idx)(u8);
+ int (*dvfs_set_idx)(u8, u8);
+ struct scpi_dvfs_info *(*dvfs_get_info)(u8);
+ int (*device_domain_id)(struct device *);
+ int (*get_transition_latency)(struct device *);
+ int (*add_opps_to_device)(struct device *);
+ int (*sensor_get_capability)(u16 *sensors);
+ int (*sensor_get_info)(u16 sensor_id, struct scpi_sensor_info *);
+ int (*sensor_get_value)(u16, u64 *);
+ int (*device_get_power_state)(u16);
+ int (*device_set_power_state)(u16, u8);
+};
+
+#if IS_REACHABLE(CONFIG_ARM_SCPI_PROTOCOL)
+struct scpi_ops *get_scpi_ops(void);
+#else
+static inline struct scpi_ops *get_scpi_ops(void) { return NULL; }
+#endif