@@ -9154,6 +9154,8 @@ M: Sudeep Holla <sudeep.holla@arm.com>
L: linux-arm-kernel@lists.infradead.org
S: Maintained
F: Documentation/devicetree/bindings/arm/arm,scpi.txt
+F: drivers/firmware/arm_scpi.c
+F: include/linux/scpi_protocol.h
SCSI CDROM DRIVER
M: Jens Axboe <axboe@kernel.dk>
@@ -139,6 +139,25 @@ config QCOM_SCM
bool
depends on ARM || ARM64
+config ARM_SCPI_PROTOCOL
+ tristate "ARM System Control and Power Interface (SCPI) Message Protocol"
+ depends on ARM_MHU
+ help
+ System Control and Power Interface (SCPI) Message Protocol is
+ defined for the purpose of communication between the Application
+ Cores(AP) and the System Control Processor(SCP). The MHU peripheral
+ provides a mechanism for inter-processor communication between SCP
+ and AP.
+
+ SCP controls most of the power managament on the Application
+ Processors. It 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.
+
+ This protocol library provides interface for all the client drivers
+ making use of the features offered by the SCP.
+
source "drivers/firmware/broadcom/Kconfig"
source "drivers/firmware/google/Kconfig"
source "drivers/firmware/efi/Kconfig"
@@ -2,6 +2,7 @@
# Makefile for the linux kernel.
#
obj-$(CONFIG_ARM_PSCI_FW) += psci.o
+obj-$(CONFIG_ARM_SCPI_PROTOCOL) += arm_scpi.o
obj-$(CONFIG_DMI) += dmi_scan.o
obj-$(CONFIG_DMI_SYSFS) += dmi-sysfs.o
obj-$(CONFIG_EDD) += edd.o
new file mode 100644
@@ -0,0 +1,711 @@
+/*
+ * 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/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 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 CMD_SIZE(cmd) (((cmd) >> CMD_DATA_SIZE_SHIFT) & CMD_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 8
+#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(20))
+
+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
+};
+
+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
+};
+
+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;
+ int num_chans;
+ 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 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 dvfs_info {
+ __le32 header;
+ struct {
+ __le32 freq;
+ __le32 m_volt;
+ } opps[MAX_DVFS_OPPS];
+} __packed;
+
+struct dvfs_get {
+ u8 index;
+} __packed;
+
+struct dvfs_set {
+ u8 domain;
+ u8 index;
+} __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;
+ }
+
+ 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)) {
+ struct scpi_shared_mem *mem = ch->rx_payload;
+ unsigned int 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 = 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)
+ 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);
+ }
+ 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 cmd, void *tx_buf, unsigned int tx_len,
+ void *rx_buf, unsigned int rx_len)
+{
+ int ret;
+ u8 chan;
+ struct scpi_xfer *msg;
+ struct scpi_chan *scpi_chan;
+
+ 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;
+
+ 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;
+ init_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 = le32_to_cpu(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(SCPI_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(SCPI_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(SCPI_CMD_SET_CLOCK_VALUE, &clk, sizeof(clk),
+ &stat, sizeof(stat));
+}
+
+static int scpi_dvfs_get_idx(u8 domain)
+{
+ int ret;
+ struct dvfs_get dvfs;
+
+ ret = scpi_send_message(SCPI_CMD_GET_DVFS, &domain, sizeof(domain),
+ &dvfs, sizeof(dvfs));
+ return ret ? ret : dvfs.index;
+}
+
+static int scpi_dvfs_set_idx(u8 domain, u8 index)
+{
+ int stat;
+ struct dvfs_set dvfs = {domain, index};
+
+ return scpi_send_message(SCPI_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(SCPI_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 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,
+};
+
+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(SCPI_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);
+ }
+ 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++)
+ list_add_tail(&xfers->node, &ch->xfers_list);
+ return 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;
+
+ count = of_count_phandle_with_args(np, "mboxes", "#mbox-cells");
+ if (count < 0) {
+ dev_err(dev, "no mboxes property in '%s'\n", np->full_name);
+ 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);
+
+ if (of_address_to_resource(shmem, 0, &res)) {
+ dev_err(dev, "failed to get SCPI payload mem resource\n");
+ ret = -EINVAL;
+ 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 = 50;
+ 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;
+ platform_set_drvdata(pdev, scpi_info);
+
+ 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"},
+ {},
+};
+
+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 +1,61 @@
+/*
+ * 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;
+};
+
+/**
+ * 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);
+};
+
+#if IS_ENABLED(CONFIG_ARM_SCPI_PROTOCOL)
+struct scpi_ops *get_scpi_ops(void);
+#else
+static inline struct scpi_ops *get_scpi_ops(void) { return NULL; }
+#endif