@@ -12998,6 +12998,15 @@ F: Documentation/devicetree/bindings/mailbox/arm,mhuv2.yaml
F: drivers/mailbox/arm_mhuv2.c
F: include/linux/mailbox/arm_mhuv2_message.h
+MAILBOX ARM MHUv3
+M: Sudeep Holla <sudeep.holla@arm.com>
+M: Cristian Marussi <cristian.marussi@arm.com>
+L: linux-kernel@vger.kernel.org
+L: linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
+S: Maintained
+F: Documentation/devicetree/bindings/mailbox/arm,mhuv3.yaml
+F: drivers/mailbox/arm_mhuv3.c
+
MAN-PAGES: MANUAL PAGES FOR LINUX -- Sections 2, 3, 4, 5, and 7
M: Alejandro Colomar <alx@kernel.org>
L: linux-man@vger.kernel.org
@@ -23,6 +23,18 @@ config ARM_MHU_V2
Say Y here if you want to build the ARM MHUv2 controller driver,
which provides unidirectional mailboxes between processing elements.
+config ARM_MHU_V3
+ tristate "ARM MHUv3 Mailbox"
+ depends on HAS_IOMEM || COMPILE_TEST
+ depends on OF
+ help
+ Say Y here if you want to build the ARM MHUv3 controller driver,
+ which provides unidirectional mailboxes between processing elements.
+
+ ARM MHUv3 controllers can implement a varying number of extensions
+ that provides different means of transports: supported extensions
+ will be discovered and possibly managed at probe-time.
+
config IMX_MBOX
tristate "i.MX Mailbox"
depends on ARCH_MXC || COMPILE_TEST
@@ -9,6 +9,8 @@ obj-$(CONFIG_ARM_MHU) += arm_mhu.o arm_mhu_db.o
obj-$(CONFIG_ARM_MHU_V2) += arm_mhuv2.o
+obj-$(CONFIG_ARM_MHU_V3) += arm_mhuv3.o
+
obj-$(CONFIG_IMX_MBOX) += imx-mailbox.o
obj-$(CONFIG_ARMADA_37XX_RWTM_MBOX) += armada-37xx-rwtm-mailbox.o
new file mode 100644
@@ -0,0 +1,1103 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ARM Message Handling Unit Version 3 (MHUv3) driver.
+ *
+ * Copyright (C) 2024 ARM Ltd.
+ *
+ * Based on ARM MHUv2 driver.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/bits.h>
+#include <linux/cleanup.h>
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/mailbox_controller.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+#include <linux/sizes.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+/* ====== MHUv3 Registers ====== */
+
+/* Maximum number of Doorbell channel windows */
+#define MHUV3_DBCW_MAX 128
+/* Number of DBCH combined interrupt status registers */
+#define MHUV3_DBCH_CMB_INT_ST_REG_CNT 4
+
+/* Number of FFCH combined interrupt status registers */
+#define MHUV3_FFCH_CMB_INT_ST_REG_CNT 2
+
+#define MHUV3_FLAG_BITS 32
+
+/* Not a typo ... */
+#define MHUV3_MAJOR_VERSION 2
+
+enum {
+ MHUV3_MBOX_CELL_TYPE,
+ MHUV3_MBOX_CELL_CHWN,
+ MHUV3_MBOX_CELL_PARAM,
+ MHUV3_MBOX_CELLS
+};
+
+/* Padding bitfields/fields represents hole in the regs MMIO */
+
+/* CTRL_Page */
+struct blk_id {
+#define id GENMASK(3, 0)
+ u32 val;
+} __packed;
+
+struct feat_spt0 {
+#define dbe_spt GENMASK(3, 0)
+#define fe_spt GENMASK(7, 4)
+#define fce_spt GENMASK(11, 8)
+ u32 val;
+} __packed;
+
+struct feat_spt1 {
+#define auto_op_spt GENMASK(3, 0)
+ u32 val;
+} __packed;
+
+struct dbch_cfg0 {
+#define num_dbch GENMASK(7, 0)
+ u32 val;
+} __packed;
+
+struct ffch_cfg0 {
+#define num_ffch GENMASK(7, 0)
+#define x8ba_spt BIT(8)
+#define x16ba_spt BIT(9)
+#define x32ba_spt BIT(10)
+#define x64ba_spt BIT(11)
+#define ffch_depth GENMASK(25, 16)
+ u32 val;
+} __packed;
+
+struct fch_cfg0 {
+#define num_fch GENMASK(9, 0)
+#define fcgi_spt BIT(10) // MBX-only
+#define num_fcg GENMASK(15, 11)
+#define num_fch_per_grp GENMASK(20, 16)
+#define fch_ws GENMASK(28, 21)
+ u32 val;
+} __packed;
+
+struct ctrl {
+#define op_req BIT(0)
+#define ch_op_mask BIT(1)
+ u32 val;
+} __packed;
+
+struct fch_ctrl {
+#define _int_en BIT(2)
+ u32 val;
+} __packed;
+
+struct iidr {
+#define implementer GENMASK(11, 0)
+#define revision GENMASK(15, 12)
+#define variant GENMASK(19, 16)
+#define product_id GENMASK(31, 20)
+ u32 val;
+} __packed;
+
+struct aidr {
+#define arch_minor_rev GENMASK(3, 0)
+#define arch_major_rev GENMASK(7, 4)
+ u32 val;
+} __packed;
+
+struct ctrl_page {
+ struct blk_id blk_id;
+ u8 pad[12];
+ struct feat_spt0 feat_spt0;
+ struct feat_spt1 feat_spt1;
+ u8 pad1[8];
+ struct dbch_cfg0 dbch_cfg0;
+ u8 pad2[12];
+ struct ffch_cfg0 ffch_cfg0;
+ u8 pad3[12];
+ struct fch_cfg0 fch_cfg0;
+ u8 pad4[188];
+ struct ctrl x_ctrl;
+ /*-- MBX-only registers --*/
+ u8 pad5[60];
+ struct fch_ctrl fch_ctrl;
+ u32 fcg_int_en;
+ u8 pad6[696];
+ /*-- End of MBX-only ---- */
+ u32 dbch_int_st[MHUV3_DBCH_CMB_INT_ST_REG_CNT];
+ u32 ffch_int_st[MHUV3_FFCH_CMB_INT_ST_REG_CNT];
+ /*-- MBX-only registers --*/
+ u8 pad7[88];
+ u32 fcg_int_st;
+ u8 pad8[12];
+ u32 fcg_grp_int_st[32];
+ u8 pad9[2760];
+ /*-- End of MBX-only ---- */
+ struct iidr iidr;
+ struct aidr aidr;
+ u32 imp_def_id[12];
+} __packed;
+
+/* DBCW_Page */
+
+struct xbcw_ctrl {
+#define comb_en BIT(0)
+ u32 val;
+} __packed;
+
+struct pdbcw_int {
+#define tfr_ack BIT(0)
+ u32 val;
+} __packed;
+
+struct pdbcw_page {
+ u32 st;
+ u8 pad[8];
+ u32 set;
+ struct pdbcw_int int_st;
+ struct pdbcw_int int_clr;
+ struct pdbcw_int int_en;
+ struct xbcw_ctrl ctrl;
+} __packed;
+
+struct mdbcw_page {
+ u32 st;
+ u32 st_msk;
+ u32 clr;
+ u8 pad[4];
+ u32 msk_st;
+ u32 msk_set;
+ u32 msk_clr;
+ struct xbcw_ctrl ctrl;
+} __packed;
+
+struct dummy_page {
+ u8 pad[SZ_4K];
+} __packed;
+
+struct mhu3_pbx_frame_reg {
+ struct ctrl_page ctrl;
+ struct pdbcw_page dbcw[MHUV3_DBCW_MAX];
+ struct dummy_page ffcw;
+ struct dummy_page fcw;
+ u8 pad[SZ_4K * 11];
+ struct dummy_page impdef;
+} __packed;
+
+struct mhu3_mbx_frame_reg {
+ struct ctrl_page ctrl;
+ struct mdbcw_page dbcw[MHUV3_DBCW_MAX];
+ struct dummy_page ffcw;
+ struct dummy_page fcw;
+ u8 pad[SZ_4K * 11];
+ struct dummy_page impdef;
+} __packed;
+
+/* Macro for reading a bitmask within a physically mapped packed struct */
+#define readl_relaxed_bitmask(_regptr, _bitmask) \
+ ({ \
+ unsigned long _rval; \
+ _rval = readl_relaxed(_regptr); \
+ FIELD_GET(_bitmask, _rval); \
+ })
+
+/* Macro for writing a bitmask within a physically mapped packed struct */
+#define writel_relaxed_bitmask(_value, _regptr, _bitmask) \
+ ({ \
+ unsigned long _rval; \
+ typeof(_regptr) _rptr = _regptr; \
+ typeof(_bitmask) _bmask = _bitmask; \
+ _rval = readl_relaxed(_rptr); \
+ _rval &= ~(_bmask); \
+ _rval |= FIELD_PREP((unsigned long long)_bmask, _value);\
+ writel_relaxed(_rval, _rptr); \
+ })
+
+/* ====== MHUv3 data structures ====== */
+
+enum mhuv3_frame {
+ PBX_FRAME,
+ MBX_FRAME,
+};
+
+static char *mhuv3_str[] = {
+ "PBX",
+ "MBX"
+};
+
+enum mhuv3_extension_type {
+ DBE_EXT,
+ FCE_EXT,
+ FE_EXT,
+ NUM_EXT
+};
+
+static char *mhuv3_ext_str[] = {
+ "DBE",
+ "FCE",
+ "FE"
+};
+
+struct mhuv3;
+
+/**
+ * struct mhuv3_protocol_ops - MHUv3 operations
+ *
+ * @rx_startup: Receiver startup callback.
+ * @rx_shutdown: Receiver shutdown callback.
+ * @read_data: Read available Sender in-band LE data (if any).
+ * @rx_complete: Acknowledge data reception to the Sender. Any out-of-band data
+ * has to have been already retrieved before calling this.
+ * @tx_startup: Sender startup callback.
+ * @tx_shutdown: Sender shutdown callback.
+ * @last_tx_done: Report back to the Sender if the last transfer has completed.
+ * @send_data: Send data to the receiver.
+ *
+ * Each supported transport protocol provides its own implementation of
+ * these operations.
+ */
+struct mhuv3_protocol_ops {
+ int (*rx_startup)(struct mhuv3 *mhu, struct mbox_chan *chan);
+ void (*rx_shutdown)(struct mhuv3 *mhu, struct mbox_chan *chan);
+ void *(*read_data)(struct mhuv3 *mhu, struct mbox_chan *chan);
+ void (*rx_complete)(struct mhuv3 *mhu, struct mbox_chan *chan);
+ void (*tx_startup)(struct mhuv3 *mhu, struct mbox_chan *chan);
+ void (*tx_shutdown)(struct mhuv3 *mhu, struct mbox_chan *chan);
+ int (*last_tx_done)(struct mhuv3 *mhu, struct mbox_chan *chan);
+ int (*send_data)(struct mhuv3 *mhu, struct mbox_chan *chan, void *arg);
+};
+
+/**
+ * struct mhuv3_mbox_chan_priv - MHUv3 channel private information
+ *
+ * @ch_idx: Channel window index associated to this mailbox channel.
+ * @doorbell: Doorbell bit number within the @ch_idx window.
+ * Only relevant to Doorbell transport.
+ * @ops: Transport protocol specific operations for this channel.
+ *
+ * Transport specific data attached to mmailbox channel priv data.
+ */
+struct mhuv3_mbox_chan_priv {
+ u32 ch_idx;
+ u32 doorbell;
+ const struct mhuv3_protocol_ops *ops;
+};
+
+/**
+ * struct mhuv3_extension - MHUv3 extension descriptor
+ *
+ * @type: Type of extension
+ * @num_chans: Max number of channels found for this extension.
+ * @base_ch_idx: First channel number assigned to this extension, picked from
+ * the set of all mailbox channels descriptors created.
+ * @mbox_of_xlate: Extension specific helper to parse DT and lookup associated
+ * channel from the related 'mboxes' property.
+ * @combined_irq_setup: Extension specific helper to setup the combined irq.
+ * @channels_init: Extension specific helper to initialize channels.
+ * @chan_from_comb_irq_get: Extension specific helper to lookup which channel
+ * triggered the combined irq.
+ * @pending_db: Array of per-channel pending doorbells.
+ * @pending_lock: Protect access to pending_db.
+ */
+struct mhuv3_extension {
+ enum mhuv3_extension_type type;
+ unsigned int num_chans;
+ unsigned int base_ch_idx;
+ struct mbox_chan *(*mbox_of_xlate)(struct mhuv3 *mhu,
+ unsigned int channel,
+ unsigned int param);
+ void (*combined_irq_setup)(struct mhuv3 *mhu);
+ int (*channels_init)(struct mhuv3 *mhu);
+ struct mbox_chan *(*chan_from_comb_irq_get)(struct mhuv3 *mhu);
+ u32 pending_db[MHUV3_DBCW_MAX];
+ /* Protect access to pending_db */
+ spinlock_t pending_lock;
+};
+
+/**
+ * struct mhuv3 - MHUv3 mailbox controller data
+ *
+ * @frame: Frame type: MBX_FRAME or PBX_FRAME.
+ * @auto_op_full: Flag to indicate if the MHU supports AutoOp full mode.
+ * @major: MHUv3 controller architectural major version.
+ * @minor: MHUv3 controller architectural minor version.
+ * @implem: MHUv3 controller IIDR implementer.
+ * @rev: MHUv3 controller IIDR revision.
+ * @var: MHUv3 controller IIDR variant.
+ * @prod_id: MHUv3 controller IIDR product_id.
+ * @num_chans: The total number of channnels discovered across all extensions.
+ * @cmb_irq: Combined IRQ number if any found defined.
+ * @ctrl: A reference to the MHUv3 control page for this block.
+ * @pbx: Base address of the PBX register mapping region.
+ * @mbx: Base address of the MBX register mapping region.
+ * @ext: Array holding descriptors for any found implemented extension.
+ * @mbox: Mailbox controller belonging to the MHU frame.
+ */
+struct mhuv3 {
+ enum mhuv3_frame frame;
+ bool auto_op_full;
+ unsigned int major;
+ unsigned int minor;
+ unsigned int implem;
+ unsigned int rev;
+ unsigned int var;
+ unsigned int prod_id;
+ unsigned int num_chans;
+ int cmb_irq;
+ struct ctrl_page __iomem *ctrl;
+ union {
+ struct mhu3_pbx_frame_reg __iomem *pbx;
+ struct mhu3_mbx_frame_reg __iomem *mbx;
+ };
+ struct mhuv3_extension *ext[NUM_EXT];
+ struct mbox_controller mbox;
+};
+
+#define mhu_from_mbox(_mbox) container_of(_mbox, struct mhuv3, mbox)
+
+typedef int (*mhuv3_extension_initializer)(struct mhuv3 *mhu);
+
+/* =================== Doorbell transport protocol operations =============== */
+
+static void mhuv3_doorbell_tx_startup(struct mhuv3 *mhu, struct mbox_chan *chan)
+{
+ struct mhuv3_mbox_chan_priv *priv = chan->con_priv;
+
+ /* Enable Transfer Acknowledgment events */
+ writel_relaxed_bitmask(0x1, &mhu->pbx->dbcw[priv->ch_idx].int_en, tfr_ack);
+}
+
+static void mhuv3_doorbell_tx_shutdown(struct mhuv3 *mhu, struct mbox_chan *chan)
+{
+ struct mhuv3_mbox_chan_priv *priv = chan->con_priv;
+ struct mhuv3_extension *e = mhu->ext[DBE_EXT];
+ unsigned long flags;
+
+ /* Disable Channel Transfer Ack events */
+ writel_relaxed_bitmask(0x0, &mhu->pbx->dbcw[priv->ch_idx].int_en, tfr_ack);
+
+ /* Clear Channel Transfer Ack and pending doorbells */
+ writel_relaxed_bitmask(0x1, &mhu->pbx->dbcw[priv->ch_idx].int_clr, tfr_ack);
+ spin_lock_irqsave(&e->pending_lock, flags);
+ e->pending_db[priv->ch_idx] = 0;
+ spin_unlock_irqrestore(&e->pending_lock, flags);
+}
+
+static int mhuv3_doorbell_rx_startup(struct mhuv3 *mhu, struct mbox_chan *chan)
+{
+ struct mhuv3_mbox_chan_priv *priv = chan->con_priv;
+
+ /* Unmask Channel Transfer events */
+ writel_relaxed(BIT(priv->doorbell), &mhu->mbx->dbcw[priv->ch_idx].msk_clr);
+
+ return 0;
+}
+
+static void mhuv3_doorbell_rx_shutdown(struct mhuv3 *mhu,
+ struct mbox_chan *chan)
+{
+ struct mhuv3_mbox_chan_priv *priv = chan->con_priv;
+
+ /* Mask Channel Transfer events */
+ writel_relaxed(BIT(priv->doorbell), &mhu->mbx->dbcw[priv->ch_idx].msk_set);
+}
+
+static void mhuv3_doorbell_rx_complete(struct mhuv3 *mhu, struct mbox_chan *chan)
+{
+ struct mhuv3_mbox_chan_priv *priv = chan->con_priv;
+
+ /* Clearing the pending transfer generates the Channel Transfer Ack */
+ writel_relaxed(BIT(priv->doorbell), &mhu->mbx->dbcw[priv->ch_idx].clr);
+}
+
+static int mhuv3_doorbell_last_tx_done(struct mhuv3 *mhu,
+ struct mbox_chan *chan)
+{
+ struct mhuv3_mbox_chan_priv *priv = chan->con_priv;
+ int done;
+
+ done = !(readl_relaxed(&mhu->pbx->dbcw[priv->ch_idx].st) &
+ BIT(priv->doorbell));
+ if (done) {
+ struct mhuv3_extension *e = mhu->ext[DBE_EXT];
+ unsigned long flags;
+
+ /* Take care to clear the pending doorbell also when polling */
+ spin_lock_irqsave(&e->pending_lock, flags);
+ e->pending_db[priv->ch_idx] &= ~BIT(priv->doorbell);
+ spin_unlock_irqrestore(&e->pending_lock, flags);
+ }
+
+ return done;
+}
+
+static int mhuv3_doorbell_send_data(struct mhuv3 *mhu, struct mbox_chan *chan,
+ void *arg)
+{
+ struct mhuv3_mbox_chan_priv *priv = chan->con_priv;
+ struct mhuv3_extension *e = mhu->ext[DBE_EXT];
+
+ scoped_guard(spinlock_irqsave, &e->pending_lock) {
+ /* Only one in-flight Transfer is allowed per-doorbell */
+ if (e->pending_db[priv->ch_idx] & BIT(priv->doorbell))
+ return -EBUSY;
+
+ e->pending_db[priv->ch_idx] |= BIT(priv->doorbell);
+ }
+
+ writel_relaxed(BIT(priv->doorbell), &mhu->pbx->dbcw[priv->ch_idx].set);
+
+ return 0;
+}
+
+static const struct mhuv3_protocol_ops mhuv3_doorbell_ops = {
+ .tx_startup = mhuv3_doorbell_tx_startup,
+ .tx_shutdown = mhuv3_doorbell_tx_shutdown,
+ .rx_startup = mhuv3_doorbell_rx_startup,
+ .rx_shutdown = mhuv3_doorbell_rx_shutdown,
+ .rx_complete = mhuv3_doorbell_rx_complete,
+ .last_tx_done = mhuv3_doorbell_last_tx_done,
+ .send_data = mhuv3_doorbell_send_data,
+};
+
+/* Sender and receiver mailbox ops */
+static bool mhuv3_sender_last_tx_done(struct mbox_chan *chan)
+{
+ struct mhuv3_mbox_chan_priv *priv = chan->con_priv;
+ struct mhuv3 *mhu = mhu_from_mbox(chan->mbox);
+
+ return priv->ops->last_tx_done(mhu, chan);
+}
+
+static int mhuv3_sender_send_data(struct mbox_chan *chan, void *data)
+{
+ struct mhuv3_mbox_chan_priv *priv = chan->con_priv;
+ struct mhuv3 *mhu = mhu_from_mbox(chan->mbox);
+
+ if (!priv->ops->last_tx_done(mhu, chan))
+ return -EBUSY;
+
+ return priv->ops->send_data(mhu, chan, data);
+}
+
+static int mhuv3_sender_startup(struct mbox_chan *chan)
+{
+ struct mhuv3_mbox_chan_priv *priv = chan->con_priv;
+ struct mhuv3 *mhu = mhu_from_mbox(chan->mbox);
+
+ if (priv->ops->tx_startup)
+ priv->ops->tx_startup(mhu, chan);
+
+ return 0;
+}
+
+static void mhuv3_sender_shutdown(struct mbox_chan *chan)
+{
+ struct mhuv3_mbox_chan_priv *priv = chan->con_priv;
+ struct mhuv3 *mhu = mhu_from_mbox(chan->mbox);
+
+ if (priv->ops->tx_shutdown)
+ priv->ops->tx_shutdown(mhu, chan);
+}
+
+static const struct mbox_chan_ops mhuv3_sender_ops = {
+ .send_data = mhuv3_sender_send_data,
+ .startup = mhuv3_sender_startup,
+ .shutdown = mhuv3_sender_shutdown,
+ .last_tx_done = mhuv3_sender_last_tx_done,
+};
+
+static int mhuv3_receiver_startup(struct mbox_chan *chan)
+{
+ struct mhuv3_mbox_chan_priv *priv = chan->con_priv;
+ struct mhuv3 *mhu = mhu_from_mbox(chan->mbox);
+
+ return priv->ops->rx_startup(mhu, chan);
+}
+
+static void mhuv3_receiver_shutdown(struct mbox_chan *chan)
+{
+ struct mhuv3_mbox_chan_priv *priv = chan->con_priv;
+ struct mhuv3 *mhu = mhu_from_mbox(chan->mbox);
+
+ priv->ops->rx_shutdown(mhu, chan);
+}
+
+static int mhuv3_receiver_send_data(struct mbox_chan *chan, void *data)
+{
+ dev_err(chan->mbox->dev,
+ "Trying to transmit on a MBX MHUv3 frame\n");
+ return -EIO;
+}
+
+static bool mhuv3_receiver_last_tx_done(struct mbox_chan *chan)
+{
+ dev_err(chan->mbox->dev, "Trying to Tx poll on a MBX MHUv3 frame\n");
+ return true;
+}
+
+static const struct mbox_chan_ops mhuv3_receiver_ops = {
+ .send_data = mhuv3_receiver_send_data,
+ .startup = mhuv3_receiver_startup,
+ .shutdown = mhuv3_receiver_shutdown,
+ .last_tx_done = mhuv3_receiver_last_tx_done,
+};
+
+static struct mbox_chan *mhuv3_dbe_mbox_of_xlate(struct mhuv3 *mhu,
+ unsigned int channel,
+ unsigned int doorbell)
+{
+ struct mhuv3_extension *e = mhu->ext[DBE_EXT];
+ struct mbox_controller *mbox = &mhu->mbox;
+ struct mbox_chan *chans = mbox->chans;
+
+ if (channel >= e->num_chans || doorbell >= MHUV3_FLAG_BITS) {
+ dev_err(mbox->dev, "Couldn't xlate to a valid channel (%d: %d)\n",
+ channel, doorbell);
+ return ERR_PTR(-ENODEV);
+ }
+
+ return &chans[e->base_ch_idx + channel * MHUV3_FLAG_BITS + doorbell];
+}
+
+static void mhuv3_dbe_combined_irq_setup(struct mhuv3 *mhu)
+{
+ struct mhuv3_extension *e = mhu->ext[DBE_EXT];
+ int i;
+
+ if (mhu->frame == PBX_FRAME) {
+ struct pdbcw_page __iomem *dbcw = mhu->pbx->dbcw;
+
+ for (i = 0; i < e->num_chans; i++) {
+ writel_relaxed_bitmask(0x1, &dbcw[i].int_clr, tfr_ack);
+ writel_relaxed_bitmask(0x0, &dbcw[i].int_en, tfr_ack);
+ writel_relaxed_bitmask(0x1, &dbcw[i].ctrl, comb_en);
+ }
+ } else {
+ struct mdbcw_page __iomem *dbcw = mhu->mbx->dbcw;
+
+ for (i = 0; i < e->num_chans; i++) {
+ writel_relaxed(0xFFFFFFFF, &dbcw[i].clr);
+ writel_relaxed(0xFFFFFFFF, &dbcw[i].msk_set);
+ writel_relaxed_bitmask(0x1, &dbcw[i].ctrl, comb_en);
+ }
+ }
+}
+
+static int mhuv3_dbe_channels_init(struct mhuv3 *mhu)
+{
+ struct mhuv3_extension *e = mhu->ext[DBE_EXT];
+ struct mbox_controller *mbox = &mhu->mbox;
+ struct mbox_chan *chans;
+ int i;
+
+ chans = mbox->chans + mbox->num_chans;
+ e->base_ch_idx = mbox->num_chans;
+ for (i = 0; i < e->num_chans; i++) {
+ struct mhuv3_mbox_chan_priv *priv;
+ int k;
+
+ for (k = 0; k < MHUV3_FLAG_BITS; k++) {
+ priv = devm_kmalloc(mbox->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->ch_idx = i;
+ priv->ops = &mhuv3_doorbell_ops;
+ priv->doorbell = k;
+ chans++->con_priv = priv;
+ mbox->num_chans++;
+ }
+ }
+
+ spin_lock_init(&e->pending_lock);
+
+ return 0;
+}
+
+static bool mhuv3_dbe_doorbell_lookup(struct mhuv3 *mhu, unsigned int channel,
+ unsigned int *db)
+{
+ struct mhuv3_extension *e = mhu->ext[DBE_EXT];
+ struct device *dev = mhu->mbox.dev;
+ u32 st;
+
+ if (mhu->frame == PBX_FRAME) {
+ u32 active_dbs, fired_dbs;
+
+ st = readl_relaxed_bitmask(&mhu->pbx->dbcw[channel].int_st,
+ tfr_ack);
+ if (!st)
+ goto err_spurious;
+
+ active_dbs = readl_relaxed(&mhu->pbx->dbcw[channel].st);
+ scoped_guard(spinlock_irqsave, &e->pending_lock) {
+ fired_dbs = e->pending_db[channel] & ~active_dbs;
+ if (!fired_dbs)
+ goto err_spurious;
+
+ *db = __ffs(fired_dbs);
+ e->pending_db[channel] &= ~BIT(*db);
+ }
+ fired_dbs &= ~BIT(*db);
+ /* Clear TFR Ack if no more doorbells pending */
+ if (!fired_dbs)
+ writel_relaxed_bitmask(0x1,
+ &mhu->pbx->dbcw[channel].int_clr,
+ tfr_ack);
+ } else {
+ st = readl_relaxed(&mhu->mbx->dbcw[channel].st_msk);
+ if (!st)
+ goto err_spurious;
+
+ *db = __ffs(st);
+ }
+
+ return true;
+
+err_spurious:
+ dev_warn(dev, "Spurious IRQ on %s channel:%d\n",
+ mhuv3_str[mhu->frame], channel);
+
+ return false;
+}
+
+static struct mbox_chan *mhuv3_dbe_chan_from_comb_irq_get(struct mhuv3 *mhu)
+{
+ struct mhuv3_extension *e = mhu->ext[DBE_EXT];
+ struct device *dev = mhu->mbox.dev;
+ int i;
+
+ for (i = 0; i < MHUV3_DBCH_CMB_INT_ST_REG_CNT; i++) {
+ unsigned int channel, db;
+ u32 cmb_st;
+
+ cmb_st = readl_relaxed(&mhu->ctrl->dbch_int_st[i]);
+ if (!cmb_st)
+ continue;
+
+ channel = i * MHUV3_FLAG_BITS + __ffs(cmb_st);
+ if (channel >= e->num_chans) {
+ dev_err(dev, "Invalid %s channel:%d\n",
+ mhuv3_str[mhu->frame], channel);
+ return ERR_PTR(-EIO);
+ }
+
+ if (!mhuv3_dbe_doorbell_lookup(mhu, channel, &db))
+ continue;
+
+ dev_dbg(dev, "Found %s ch[%d]/db[%d]\n",
+ mhuv3_str[mhu->frame], channel, db);
+
+ return &mhu->mbox.chans[channel * MHUV3_FLAG_BITS + db];
+ }
+
+ return ERR_PTR(-EIO);
+}
+
+static int mhuv3_dbe_init(struct mhuv3 *mhu)
+{
+ struct device *dev = mhu->mbox.dev;
+ struct mhuv3_extension *e;
+
+ if (!readl_relaxed_bitmask(&mhu->ctrl->feat_spt0, dbe_spt))
+ return 0;
+
+ dev_dbg(dev, "%s: Initializing DBE Extension.\n", mhuv3_str[mhu->frame]);
+
+ e = devm_kzalloc(dev, sizeof(*e), GFP_KERNEL);
+ if (!e)
+ return -ENOMEM;
+
+ e->type = DBE_EXT;
+ /* Note that, by the spec, the number of channels is (num_dbch + 1) */
+ e->num_chans =
+ readl_relaxed_bitmask(&mhu->ctrl->dbch_cfg0, num_dbch) + 1;
+ e->mbox_of_xlate = mhuv3_dbe_mbox_of_xlate;
+ e->combined_irq_setup = mhuv3_dbe_combined_irq_setup;
+ e->channels_init = mhuv3_dbe_channels_init;
+ e->chan_from_comb_irq_get = mhuv3_dbe_chan_from_comb_irq_get;
+
+ mhu->num_chans += e->num_chans * MHUV3_FLAG_BITS;
+ mhu->ext[DBE_EXT] = e;
+
+ dev_dbg(dev, "%s: found %d DBE channels.\n",
+ mhuv3_str[mhu->frame], e->num_chans);
+
+ return 0;
+}
+
+static int mhuv3_fce_init(struct mhuv3 *mhu)
+{
+ struct device *dev = mhu->mbox.dev;
+
+ if (!readl_relaxed_bitmask(&mhu->ctrl->feat_spt0, fce_spt))
+ return 0;
+
+ dev_dbg(dev, "%s: FCE Extension not supported by driver.\n",
+ mhuv3_str[mhu->frame]);
+
+ return 0;
+}
+
+static int mhuv3_fe_init(struct mhuv3 *mhu)
+{
+ struct device *dev = mhu->mbox.dev;
+
+ if (!readl_relaxed_bitmask(&mhu->ctrl->feat_spt0, fe_spt))
+ return 0;
+
+ dev_dbg(dev, "%s: FE Extension not supported by driver.\n",
+ mhuv3_str[mhu->frame]);
+
+ return 0;
+}
+
+static mhuv3_extension_initializer mhuv3_extension_init[NUM_EXT] = {
+ mhuv3_dbe_init,
+ mhuv3_fce_init,
+ mhuv3_fe_init,
+};
+
+static int mhuv3_initialize_channels(struct device *dev, struct mhuv3 *mhu)
+{
+ struct mbox_controller *mbox = &mhu->mbox;
+ int i, ret = 0;
+
+ mbox->chans = devm_kcalloc(dev, mhu->num_chans,
+ sizeof(*mbox->chans), GFP_KERNEL);
+ if (!mbox->chans)
+ return dev_err_probe(dev, -ENOMEM,
+ "Failed to initialize channels\n");
+
+ for (i = 0; i < NUM_EXT && !ret; i++)
+ if (mhu->ext[i])
+ ret = mhu->ext[i]->channels_init(mhu);
+
+ return ret;
+}
+
+static struct mbox_chan *mhuv3_mbox_of_xlate(struct mbox_controller *mbox,
+ const struct of_phandle_args *pa)
+{
+ struct mhuv3 *mhu = mhu_from_mbox(mbox);
+ unsigned int type, channel, param;
+
+ if (pa->args_count != MHUV3_MBOX_CELLS)
+ return ERR_PTR(-EINVAL);
+
+ type = pa->args[MHUV3_MBOX_CELL_TYPE];
+ if (type >= NUM_EXT)
+ return ERR_PTR(-EINVAL);
+
+ channel = pa->args[MHUV3_MBOX_CELL_CHWN];
+ param = pa->args[MHUV3_MBOX_CELL_PARAM];
+
+ return mhu->ext[type]->mbox_of_xlate(mhu, channel, param);
+}
+
+static void mhu_frame_cleanup_actions(void *data)
+{
+ struct mhuv3 *mhu = data;
+
+ writel_relaxed_bitmask(0x0, &mhu->ctrl->x_ctrl, op_req);
+}
+
+static int mhuv3_frame_init(struct mhuv3 *mhu, void __iomem *regs)
+{
+ struct device *dev = mhu->mbox.dev;
+ int i;
+
+ mhu->ctrl = regs;
+ mhu->frame = readl_relaxed_bitmask(&mhu->ctrl->blk_id, id);
+ if (mhu->frame > MBX_FRAME)
+ return dev_err_probe(dev, -EINVAL,
+ "Invalid Frame type- %d\n", mhu->frame);
+
+ mhu->major = readl_relaxed_bitmask(&mhu->ctrl->aidr, arch_major_rev);
+ mhu->minor = readl_relaxed_bitmask(&mhu->ctrl->aidr, arch_minor_rev);
+ mhu->implem = readl_relaxed_bitmask(&mhu->ctrl->iidr, implementer);
+ mhu->rev = readl_relaxed_bitmask(&mhu->ctrl->iidr, revision);
+ mhu->var = readl_relaxed_bitmask(&mhu->ctrl->iidr, variant);
+ mhu->prod_id = readl_relaxed_bitmask(&mhu->ctrl->iidr, product_id);
+ if (mhu->major != MHUV3_MAJOR_VERSION)
+ return dev_err_probe(dev, -EINVAL,
+ "Unsupported MHU %s block - major:%d minor:%d\n",
+ mhuv3_str[mhu->frame], mhu->major,
+ mhu->minor);
+
+ mhu->auto_op_full =
+ !!readl_relaxed_bitmask(&mhu->ctrl->feat_spt1, auto_op_spt);
+ /* Request the PBX/MBX to remain operational */
+ if (mhu->auto_op_full) {
+ writel_relaxed_bitmask(0x1, &mhu->ctrl->x_ctrl, op_req);
+ devm_add_action_or_reset(dev, mhu_frame_cleanup_actions, mhu);
+ }
+
+ dev_dbg(dev,
+ "Found MHU %s block - major:%d minor:%d\n implem:0x%X rev:0x%X var:0x%X prod_id:0x%X",
+ mhuv3_str[mhu->frame], mhu->major, mhu->minor,
+ mhu->implem, mhu->rev, mhu->var, mhu->prod_id);
+
+ if (mhu->frame == PBX_FRAME)
+ mhu->pbx = regs;
+ else
+ mhu->mbx = regs;
+
+ for (i = 0; i < NUM_EXT; i++) {
+ int ret;
+
+ /*
+ * Note that extensions initialization fails only when such
+ * extension initialization routine fails and the extensions
+ * was found to be supported in hardware and in software.
+ */
+ ret = mhuv3_extension_init[i](mhu);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "Failed to initialize %s %s\n",
+ mhuv3_str[mhu->frame],
+ mhuv3_ext_str[i]);
+ }
+
+ return 0;
+}
+
+static irqreturn_t mhuv3_pbx_comb_interrupt(int irq, void *arg)
+{
+ unsigned int i, found = 0;
+ struct mhuv3 *mhu = arg;
+ struct mbox_chan *chan;
+ struct device *dev;
+ int ret = IRQ_NONE;
+
+ dev = mhu->mbox.dev;
+ for (i = 0; i < NUM_EXT; i++) {
+ struct mhuv3_mbox_chan_priv *priv;
+
+ /* FCE does not participate to the PBX combined */
+ if (i == FCE_EXT || !mhu->ext[i])
+ continue;
+
+ chan = mhu->ext[i]->chan_from_comb_irq_get(mhu);
+ if (IS_ERR(chan))
+ continue;
+
+ found++;
+ priv = chan->con_priv;
+ if (!chan->cl) {
+ dev_warn(dev, "TX Ack on UNBOUND channel (%u)\n",
+ priv->ch_idx);
+ continue;
+ }
+
+ mbox_chan_txdone(chan, 0);
+ ret = IRQ_HANDLED;
+ }
+
+ if (found == 0)
+ dev_warn_once(dev, "Failed to find channel for the TX interrupt\n");
+
+ return ret;
+}
+
+static irqreturn_t mhuv3_mbx_comb_interrupt(int irq, void *arg)
+{
+ unsigned int i, found = 0;
+ struct mhuv3 *mhu = arg;
+ struct mbox_chan *chan;
+ struct device *dev;
+ int ret = IRQ_NONE;
+
+ dev = mhu->mbox.dev;
+ for (i = 0; i < NUM_EXT; i++) {
+ struct mhuv3_mbox_chan_priv *priv;
+ void *data __free(kfree) = NULL;
+
+ if (!mhu->ext[i])
+ continue;
+
+ /* Process any extension which could be source of the IRQ */
+ chan = mhu->ext[i]->chan_from_comb_irq_get(mhu);
+ if (IS_ERR(chan))
+ continue;
+
+ found++;
+ /* From here on we need to call rx_complete even on error */
+ priv = chan->con_priv;
+ if (!chan->cl) {
+ dev_warn(dev, "RX Data on UNBOUND channel (%u)\n",
+ priv->ch_idx);
+ goto rx_ack;
+ }
+
+ /* Read optional in-band LE data first. */
+ if (priv->ops->read_data) {
+ data = priv->ops->read_data(mhu, chan);
+ if (IS_ERR(data)) {
+ dev_err(dev,
+ "Failed to read in-band data. err:%ld\n",
+ PTR_ERR(no_free_ptr(data)));
+ goto rx_ack;
+ }
+ }
+
+ mbox_chan_received_data(chan, data);
+ ret = IRQ_HANDLED;
+
+ /*
+ * Acknowledge transfer after any possible optional
+ * out-of-band data has also been retrieved via
+ * mbox_chan_received_data().
+ */
+rx_ack:
+ if (priv->ops->rx_complete)
+ priv->ops->rx_complete(mhu, chan);
+ }
+
+ if (found == 0)
+ dev_warn_once(dev, "Failed to find channel for the RX interrupt\n");
+
+ return ret;
+}
+
+static int mhuv3_setup_pbx(struct mhuv3 *mhu)
+{
+ struct device *dev = mhu->mbox.dev;
+
+ mhu->mbox.ops = &mhuv3_sender_ops;
+
+ if (mhu->cmb_irq > 0) {
+ int ret, i;
+
+ ret = devm_request_threaded_irq(dev, mhu->cmb_irq, NULL,
+ mhuv3_pbx_comb_interrupt,
+ IRQF_ONESHOT, "mhuv3-pbx", mhu);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "Failed to request PBX IRQ\n");
+
+ mhu->mbox.txdone_irq = true;
+ mhu->mbox.txdone_poll = false;
+
+ for (i = 0; i < NUM_EXT; i++)
+ if (mhu->ext[i])
+ mhu->ext[i]->combined_irq_setup(mhu);
+
+ dev_dbg(dev, "MHUv3 PBX IRQs initialized.\n");
+
+ return 0;
+ }
+
+ dev_info(dev, "Using PBX in Tx polling mode.\n");
+ mhu->mbox.txdone_irq = false;
+ mhu->mbox.txdone_poll = true;
+ mhu->mbox.txpoll_period = 1;
+
+ return 0;
+}
+
+static int mhuv3_setup_mbx(struct mhuv3 *mhu)
+{
+ struct device *dev = mhu->mbox.dev;
+ int ret, i;
+
+ mhu->mbox.ops = &mhuv3_receiver_ops;
+
+ if (mhu->cmb_irq <= 0)
+ return dev_err_probe(dev, -EINVAL,
+ "MBX combined IRQ is missing !\n");
+
+ ret = devm_request_threaded_irq(dev, mhu->cmb_irq, NULL,
+ mhuv3_mbx_comb_interrupt, IRQF_ONESHOT,
+ "mhuv3-mbx", mhu);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to request MBX IRQ\n");
+
+ for (i = 0; i < NUM_EXT; i++)
+ if (mhu->ext[i])
+ mhu->ext[i]->combined_irq_setup(mhu);
+
+ dev_dbg(dev, "MHUv3 MBX IRQs initialized.\n");
+
+ return ret;
+}
+
+static int mhuv3_irqs_init(struct mhuv3 *mhu, struct platform_device *pdev)
+{
+ dev_dbg(mhu->mbox.dev, "Initializing %s block.\n",
+ mhuv3_str[mhu->frame]);
+
+ if (mhu->frame == PBX_FRAME) {
+ mhu->cmb_irq =
+ platform_get_irq_byname_optional(pdev, "combined");
+ return mhuv3_setup_pbx(mhu);
+ }
+
+ mhu->cmb_irq = platform_get_irq_byname(pdev, "combined");
+ return mhuv3_setup_mbx(mhu);
+}
+
+static int mhuv3_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ void __iomem *regs;
+ struct mhuv3 *mhu;
+ int ret;
+
+ mhu = devm_kzalloc(dev, sizeof(*mhu), GFP_KERNEL);
+ if (!mhu)
+ return -ENOMEM;
+
+ regs = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(regs))
+ return PTR_ERR(regs);
+
+ mhu->mbox.dev = dev;
+ ret = mhuv3_frame_init(mhu, regs);
+ if (ret)
+ return ret;
+
+ ret = mhuv3_irqs_init(mhu, pdev);
+ if (ret)
+ return ret;
+
+ mhu->mbox.of_xlate = mhuv3_mbox_of_xlate;
+ ret = mhuv3_initialize_channels(dev, mhu);
+ if (ret)
+ return ret;
+
+ ret = devm_mbox_controller_register(dev, &mhu->mbox);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "Failed to register ARM MHUv3 driver\n");
+
+ return ret;
+}
+
+static const struct of_device_id mhuv3_of_match[] = {
+ { .compatible = "arm,mhuv3", .data = NULL },
+ {}
+};
+MODULE_DEVICE_TABLE(of, mhuv3_of_match);
+
+static struct platform_driver mhuv3_driver = {
+ .driver = {
+ .name = "arm-mhuv3-mailbox",
+ .of_match_table = mhuv3_of_match,
+ },
+ .probe = mhuv3_probe,
+};
+module_platform_driver(mhuv3_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("ARM MHUv3 Driver");
+MODULE_AUTHOR("Cristian Marussi <cristian.marussi@arm.com>");
Add support for ARM MHUv3 mailbox controller. Support is limited to the MHUv3 Doorbell extension using only the PBX/MBX combined interrupts. Signed-off-by: Cristian Marussi <cristian.marussi@arm.com> --- v4 -> v5 - changed Kconfig depends on to just need oF && HAS_IOMEM - fixed LLVM warnings on FIELD_PREP as reported-by <lkp@intel.com> v3 -> v4 - avoid magic numbers for padding holes - renaming various enums terminators to count_ instead of max_ - using scoped_guards for spinlock_save - dropping FIRST_EXT naming for 0-indexed enum - less indentation by using early returns or continue on failure-paths - use dev_err_probe where appropriate - less noisy with dev_dbg - refactored mhuv3_mbx_comb_interrupt using __free cleanups for .read_data - refactored doorbell lookups with scoped_guards - fail on IRQ request failures: not carrying-on best effort - drop usage of platform_set_drvdata and .remove in favour of devm_add_action_or_reset - review failures handling on extensions initialization - removed name clashes - more comments on regs decorations - decreasing line-lengths definitions - use __ffs instead of __builtin_ctz - dropped used of bitfields in favour of bitmasks - reading implementer/revision/variant/product_id - fixed misspellings v1 -> v2 - fixed checkpatch warnings about side-effects - fixed sparse errors as reported | Reported-by: kernel test robot <lkp@intel.com> | Closes: https://lore.kernel.org/oe-kbuild-all/202403290015.tCLXudqC-lkp@intel.com/ --- MAINTAINERS | 9 + drivers/mailbox/Kconfig | 12 + drivers/mailbox/Makefile | 2 + drivers/mailbox/arm_mhuv3.c | 1103 +++++++++++++++++++++++++++++++++++ 4 files changed, 1126 insertions(+) create mode 100644 drivers/mailbox/arm_mhuv3.c