Merge tag 'imx-drivers-4.20-2' of git://git.kernel.org/pub/scm/linux/kernel/git/shawnguo/linux into next/drivers

i.MX drivers change for 4.20, round 2:
 - A series from Aisheng Dong to add SCU firmware driver for i.MX8
   SoCs.  It implements IPC mechanism based on mailbox for message
   exchange between AP and SCU firmware, and a set of SCU IPC
   service APIs used by clients like i.MX8 power domain and clock
   drivers.

* tag 'imx-drivers-4.20-2' of git://git.kernel.org/pub/scm/linux/kernel/git/shawnguo/linux:
  MAINTAINERS: imx: include drivers/firmware/imx path
  firmware: imx: add misc svc support
  firmware: imx: add SCU firmware driver support
  dt-bindings: arm: fsl: add scu binding doc

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

6 files changed, 384 insertions, 0 deletions

diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
index 36344cba764e..7670e8dda829 100644
--- a/drivers/firmware/Kconfig
+++ b/drivers/firmware/Kconfig
@@ -289,6 +289,7 @@ config HAVE_ARM_SMCCC
 source "drivers/firmware/broadcom/Kconfig"
 source "drivers/firmware/google/Kconfig"
 source "drivers/firmware/efi/Kconfig"
+source "drivers/firmware/imx/Kconfig"
 source "drivers/firmware/meson/Kconfig"
 source "drivers/firmware/tegra/Kconfig"
 source "drivers/firmware/xilinx/Kconfig"
diff --git a/drivers/firmware/Makefile b/drivers/firmware/Makefile
index 99583d3df52f..13660a951437 100644
--- a/drivers/firmware/Makefile
+++ b/drivers/firmware/Makefile
@@ -31,5 +31,6 @@ obj-y				+= meson/
 obj-$(CONFIG_GOOGLE_FIRMWARE)   += google/
 obj-$(CONFIG_EFI)               += efi/
 obj-$(CONFIG_UEFI_CPER)         += efi/
+obj-y                           += imx/
 obj-y                           += tegra/
 obj-y                           += xilinx/
diff --git a/drivers/firmware/imx/Kconfig b/drivers/firmware/imx/Kconfig
new file mode 100644
index 000000000000..b170c2851e48
--- /dev/null
+++ b/drivers/firmware/imx/Kconfig
@@ -0,0 +1,11 @@
+config IMX_SCU
+        bool "IMX SCU Protocol driver"
+        depends on IMX_MBOX
+        help
+          The System Controller Firmware (SCFW) is a low-level system function
+          which runs on a dedicated Cortex-M core to provide power, clock, and
+          resource management. It exists on some i.MX8 processors. e.g. i.MX8QM
+          (QM, QP), and i.MX8QX (QXP, DX).
+
+          This driver manages the IPC interface between host CPU and the
+          SCU firmware running on M4.
diff --git a/drivers/firmware/imx/Makefile b/drivers/firmware/imx/Makefile
new file mode 100644
index 000000000000..0ac04dfda8d4
--- /dev/null
+++ b/drivers/firmware/imx/Makefile
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_IMX_SCU)   += imx-scu.o misc.o
diff --git a/drivers/firmware/imx/imx-scu.c b/drivers/firmware/imx/imx-scu.c
new file mode 100644
index 000000000000..2bb1a19c413f
--- /dev/null
+++ b/drivers/firmware/imx/imx-scu.c
@@ -0,0 +1,270 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2018 NXP
+ *  Author: Dong Aisheng <aisheng.dong@nxp.com>
+ *
+ * Implementation of the SCU IPC functions using MUs (client side).
+ *
+ */
+
+#include <linux/err.h>
+#include <linux/firmware/imx/types.h>
+#include <linux/firmware/imx/ipc.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/mailbox_client.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+
+#define SCU_MU_CHAN_NUM         8
+#define MAX_RX_TIMEOUT          (msecs_to_jiffies(30))
+
+struct imx_sc_chan {
+        struct imx_sc_ipc *sc_ipc;
+
+        struct mbox_client cl;
+        struct mbox_chan *ch;
+        int idx;
+};
+
+struct imx_sc_ipc {
+        /* SCU uses 4 Tx and 4 Rx channels */
+        struct imx_sc_chan chans[SCU_MU_CHAN_NUM];
+        struct device *dev;
+        struct mutex lock;
+        struct completion done;
+
+        /* temporarily store the SCU msg */
+        u32 *msg;
+        u8 rx_size;
+        u8 count;
+};
+
+/*
+ * This type is used to indicate error response for most functions.
+ */
+enum imx_sc_error_codes {
+        IMX_SC_ERR_NONE = 0,    /* Success */
+        IMX_SC_ERR_VERSION = 1, /* Incompatible API version */
+        IMX_SC_ERR_CONFIG = 2,  /* Configuration error */
+        IMX_SC_ERR_PARM = 3,    /* Bad parameter */
+        IMX_SC_ERR_NOACCESS = 4,        /* Permission error (no access) */
+        IMX_SC_ERR_LOCKED = 5,  /* Permission error (locked) */
+        IMX_SC_ERR_UNAVAILABLE = 6,     /* Unavailable (out of resources) */
+        IMX_SC_ERR_NOTFOUND = 7,        /* Not found */
+        IMX_SC_ERR_NOPOWER = 8, /* No power */
+        IMX_SC_ERR_IPC = 9,             /* Generic IPC error */
+        IMX_SC_ERR_BUSY = 10,   /* Resource is currently busy/active */
+        IMX_SC_ERR_FAIL = 11,   /* General I/O failure */
+        IMX_SC_ERR_LAST
+};
+
+static int imx_sc_linux_errmap[IMX_SC_ERR_LAST] = {
+        0,       /* IMX_SC_ERR_NONE */
+        -EINVAL, /* IMX_SC_ERR_VERSION */
+        -EINVAL, /* IMX_SC_ERR_CONFIG */
+        -EINVAL, /* IMX_SC_ERR_PARM */
+        -EACCES, /* IMX_SC_ERR_NOACCESS */
+        -EACCES, /* IMX_SC_ERR_LOCKED */
+        -ERANGE, /* IMX_SC_ERR_UNAVAILABLE */
+        -EEXIST, /* IMX_SC_ERR_NOTFOUND */
+        -EPERM,  /* IMX_SC_ERR_NOPOWER */
+        -EPIPE,  /* IMX_SC_ERR_IPC */
+        -EBUSY,  /* IMX_SC_ERR_BUSY */
+        -EIO,    /* IMX_SC_ERR_FAIL */
+};
+
+static struct imx_sc_ipc *imx_sc_ipc_handle;
+
+static inline int imx_sc_to_linux_errno(int errno)
+{
+        if (errno >= IMX_SC_ERR_NONE && errno < IMX_SC_ERR_LAST)
+                return imx_sc_linux_errmap[errno];
+        return -EIO;
+}
+
+/*
+ * Get the default handle used by SCU
+ */
+int imx_scu_get_handle(struct imx_sc_ipc **ipc)
+{
+        if (!imx_sc_ipc_handle)
+                return -EPROBE_DEFER;
+
+        *ipc = imx_sc_ipc_handle;
+        return 0;
+}
+EXPORT_SYMBOL(imx_scu_get_handle);
+
+static void imx_scu_rx_callback(struct mbox_client *c, void *msg)
+{
+        struct imx_sc_chan *sc_chan = container_of(c, struct imx_sc_chan, cl);
+        struct imx_sc_ipc *sc_ipc = sc_chan->sc_ipc;
+        struct imx_sc_rpc_msg *hdr;
+        u32 *data = msg;
+
+        if (sc_chan->idx == 0) {
+                hdr = msg;
+                sc_ipc->rx_size = hdr->size;
+                dev_dbg(sc_ipc->dev, "msg rx size %u\n", sc_ipc->rx_size);
+                if (sc_ipc->rx_size > 4)
+                        dev_warn(sc_ipc->dev, "RPC does not support receiving over 4 words: %u\n",
+                                 sc_ipc->rx_size);
+        }
+
+        sc_ipc->msg[sc_chan->idx] = *data;
+        sc_ipc->count++;
+
+        dev_dbg(sc_ipc->dev, "mu %u msg %u 0x%x\n", sc_chan->idx,
+                sc_ipc->count, *data);
+
+        if ((sc_ipc->rx_size != 0) && (sc_ipc->count == sc_ipc->rx_size))
+                complete(&sc_ipc->done);
+}
+
+static int imx_scu_ipc_write(struct imx_sc_ipc *sc_ipc, void *msg)
+{
+        struct imx_sc_rpc_msg *hdr = msg;
+        struct imx_sc_chan *sc_chan;
+        u32 *data = msg;
+        int ret;
+        int i;
+
+        /* Check size */
+        if (hdr->size > IMX_SC_RPC_MAX_MSG)
+                return -EINVAL;
+
+        dev_dbg(sc_ipc->dev, "RPC SVC %u FUNC %u SIZE %u\n", hdr->svc,
+                hdr->func, hdr->size);
+
+        for (i = 0; i < hdr->size; i++) {
+                sc_chan = &sc_ipc->chans[i % 4];
+                ret = mbox_send_message(sc_chan->ch, &data[i]);
+                if (ret < 0)
+                        return ret;
+        }
+
+        return 0;
+}
+
+/*
+ * RPC command/response
+ */
+int imx_scu_call_rpc(struct imx_sc_ipc *sc_ipc, void *msg, bool have_resp)
+{
+        struct imx_sc_rpc_msg *hdr;
+        int ret;
+
+        if (WARN_ON(!sc_ipc || !msg))
+                return -EINVAL;
+
+        mutex_lock(&sc_ipc->lock);
+        reinit_completion(&sc_ipc->done);
+
+        sc_ipc->msg = msg;
+        sc_ipc->count = 0;
+        ret = imx_scu_ipc_write(sc_ipc, msg);
+        if (ret < 0) {
+                dev_err(sc_ipc->dev, "RPC send msg failed: %d\n", ret);
+                goto out;
+        }
+
+        if (have_resp) {
+                if (!wait_for_completion_timeout(&sc_ipc->done,
+                                                 MAX_RX_TIMEOUT)) {
+                        dev_err(sc_ipc->dev, "RPC send msg timeout\n");
+                        mutex_unlock(&sc_ipc->lock);
+                        return -ETIMEDOUT;
+                }
+
+                /* response status is stored in hdr->func field */
+                hdr = msg;
+                ret = hdr->func;
+        }
+
+out:
+        mutex_unlock(&sc_ipc->lock);
+
+        dev_dbg(sc_ipc->dev, "RPC SVC done\n");
+
+        return imx_sc_to_linux_errno(ret);
+}
+EXPORT_SYMBOL(imx_scu_call_rpc);
+
+static int imx_scu_probe(struct platform_device *pdev)
+{
+        struct device *dev = &pdev->dev;
+        struct imx_sc_ipc *sc_ipc;
+        struct imx_sc_chan *sc_chan;
+        struct mbox_client *cl;
+        char *chan_name;
+        int ret;
+        int i;
+
+        sc_ipc = devm_kzalloc(dev, sizeof(*sc_ipc), GFP_KERNEL);
+        if (!sc_ipc)
+                return -ENOMEM;
+
+        for (i = 0; i < SCU_MU_CHAN_NUM; i++) {
+                if (i < 4)
+                        chan_name = kasprintf(GFP_KERNEL, "tx%d", i);
+                else
+                        chan_name = kasprintf(GFP_KERNEL, "rx%d", i - 4);
+
+                if (!chan_name)
+                        return -ENOMEM;
+
+                sc_chan = &sc_ipc->chans[i];
+                cl = &sc_chan->cl;
+                cl->dev = dev;
+                cl->tx_block = false;
+                cl->knows_txdone = true;
+                cl->rx_callback = imx_scu_rx_callback;
+
+                sc_chan->sc_ipc = sc_ipc;
+                sc_chan->idx = i % 4;
+                sc_chan->ch = mbox_request_channel_byname(cl, chan_name);
+                if (IS_ERR(sc_chan->ch)) {
+                        ret = PTR_ERR(sc_chan->ch);
+                        if (ret != -EPROBE_DEFER)
+                                dev_err(dev, "Failed to request mbox chan %s ret %d\n",
+                                        chan_name, ret);
+                        return ret;
+                }
+
+                dev_dbg(dev, "request mbox chan %s\n", chan_name);
+                /* chan_name is not used anymore by framework */
+                kfree(chan_name);
+        }
+
+        sc_ipc->dev = dev;
+        mutex_init(&sc_ipc->lock);
+        init_completion(&sc_ipc->done);
+
+        imx_sc_ipc_handle = sc_ipc;
+
+        dev_info(dev, "NXP i.MX SCU Initialized\n");
+
+        return devm_of_platform_populate(dev);
+}
+
+static const struct of_device_id imx_scu_match[] = {
+        { .compatible = "fsl,imx-scu", },
+        { /* Sentinel */ }
+};
+
+static struct platform_driver imx_scu_driver = {
+        .driver = {
+                .name = "imx-scu",
+                .of_match_table = imx_scu_match,
+        },
+        .probe = imx_scu_probe,
+};
+builtin_platform_driver(imx_scu_driver);
+
+MODULE_AUTHOR("Dong Aisheng <aisheng.dong@nxp.com>");
+MODULE_DESCRIPTION("IMX SCU firmware protocol driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/firmware/imx/misc.c b/drivers/firmware/imx/misc.c
new file mode 100644
index 000000000000..97f5424dbac9
--- /dev/null
+++ b/drivers/firmware/imx/misc.c
@@ -0,0 +1,99 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2016 Freescale Semiconductor, Inc.
+ * Copyright 2017~2018 NXP
+ *  Author: Dong Aisheng <aisheng.dong@nxp.com>
+ *
+ * File containing client-side RPC functions for the MISC service. These
+ * function are ported to clients that communicate to the SC.
+ *
+ */
+
+#include <linux/firmware/imx/svc/misc.h>
+
+struct imx_sc_msg_req_misc_set_ctrl {
+        struct imx_sc_rpc_msg hdr;
+        u32 ctrl;
+        u32 val;
+        u16 resource;
+} __packed;
+
+struct imx_sc_msg_req_misc_get_ctrl {
+        struct imx_sc_rpc_msg hdr;
+        u32 ctrl;
+        u16 resource;
+} __packed;
+
+struct imx_sc_msg_resp_misc_get_ctrl {
+        struct imx_sc_rpc_msg hdr;
+        u32 val;
+} __packed;
+
+/*
+ * This function sets a miscellaneous control value.
+ *
+ * @param[in]     ipc         IPC handle
+ * @param[in]     resource    resource the control is associated with
+ * @param[in]     ctrl        control to change
+ * @param[in]     val         value to apply to the control
+ *
+ * @return Returns 0 for success and < 0 for errors.
+ */
+
+int imx_sc_misc_set_control(struct imx_sc_ipc *ipc, u32 resource,
+                            u8 ctrl, u32 val)
+{
+        struct imx_sc_msg_req_misc_set_ctrl msg;
+        struct imx_sc_rpc_msg *hdr = &msg.hdr;
+
+        hdr->ver = IMX_SC_RPC_VERSION;
+        hdr->svc = (uint8_t)IMX_SC_RPC_SVC_MISC;
+        hdr->func = (uint8_t)IMX_SC_MISC_FUNC_SET_CONTROL;
+        hdr->size = 4;
+
+        msg.ctrl = ctrl;
+        msg.val = val;
+        msg.resource = resource;
+
+        return imx_scu_call_rpc(ipc, &msg, true);
+}
+EXPORT_SYMBOL(imx_sc_misc_set_control);
+
+/*
+ * This function gets a miscellaneous control value.
+ *
+ * @param[in]     ipc         IPC handle
+ * @param[in]     resource    resource the control is associated with
+ * @param[in]     ctrl        control to get
+ * @param[out]    val         pointer to return the control value
+ *
+ * @return Returns 0 for success and < 0 for errors.
+ */
+
+int imx_sc_misc_get_control(struct imx_sc_ipc *ipc, u32 resource,
+                            u8 ctrl, u32 *val)
+{
+        struct imx_sc_msg_req_misc_get_ctrl msg;
+        struct imx_sc_msg_resp_misc_get_ctrl *resp;
+        struct imx_sc_rpc_msg *hdr = &msg.hdr;
+        int ret;
+
+        hdr->ver = IMX_SC_RPC_VERSION;
+        hdr->svc = (uint8_t)IMX_SC_RPC_SVC_MISC;
+        hdr->func = (uint8_t)IMX_SC_MISC_FUNC_GET_CONTROL;
+        hdr->size = 3;
+
+        msg.ctrl = ctrl;
+        msg.resource = resource;
+
+        ret = imx_scu_call_rpc(ipc, &msg, true);
+        if (ret)
+                return ret;
+
+        resp = (struct imx_sc_msg_resp_misc_get_ctrl *)&msg;
+        if (val != NULL)
+                *val = resp->val;
+
+        return 0;
+}
+EXPORT_SYMBOL(imx_sc_misc_get_control);