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-rw-r--r--drivers/mailbox/Kconfig10
-rw-r--r--drivers/mailbox/Makefile2
-rw-r--r--drivers/mailbox/mtk-gpueb-mailbox.c319
3 files changed, 331 insertions, 0 deletions
diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
index 02432d4a5ccd..2016defda1fa 100644
--- a/drivers/mailbox/Kconfig
+++ b/drivers/mailbox/Kconfig
@@ -294,6 +294,16 @@ config MTK_CMDQ_MBOX
critical time limitation, such as updating display configuration
during the vblank.
+config MTK_GPUEB_MBOX
+ tristate "MediaTek GPUEB Mailbox Support"
+ depends on ARCH_MEDIATEK || COMPILE_TEST
+ help
+ The MediaTek GPUEB mailbox is used to communicate with the embedded
+ controller in charge of GPU frequency and power management on some
+ MediaTek SoCs, such as the MT8196.
+ Say Y or m here if you want to support the MT8196 SoC in your kernel
+ build.
+
config ZYNQMP_IPI_MBOX
tristate "Xilinx ZynqMP IPI Mailbox"
depends on ARCH_ZYNQMP && OF
diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
index 98a68f838486..564d06e71313 100644
--- a/drivers/mailbox/Makefile
+++ b/drivers/mailbox/Makefile
@@ -63,6 +63,8 @@ obj-$(CONFIG_MTK_ADSP_MBOX) += mtk-adsp-mailbox.o
obj-$(CONFIG_MTK_CMDQ_MBOX) += mtk-cmdq-mailbox.o
+obj-$(CONFIG_MTK_GPUEB_MBOX) += mtk-gpueb-mailbox.o
+
obj-$(CONFIG_ZYNQMP_IPI_MBOX) += zynqmp-ipi-mailbox.o
obj-$(CONFIG_SUN6I_MSGBOX) += sun6i-msgbox.o
diff --git a/drivers/mailbox/mtk-gpueb-mailbox.c b/drivers/mailbox/mtk-gpueb-mailbox.c
new file mode 100644
index 000000000000..925bcf21f650
--- /dev/null
+++ b/drivers/mailbox/mtk-gpueb-mailbox.c
@@ -0,0 +1,319 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * MediaTek GPUEB mailbox driver for SoCs such as the MT8196
+ *
+ * Copyright (C) 2025, Collabora Ltd.
+ *
+ * Developers harmed in the making of this driver:
+ * - Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
+ */
+
+#include <linux/atomic.h>
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/mailbox_controller.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+
+#define GPUEB_MBOX_CTL_TX_STS 0x00
+#define GPUEB_MBOX_CTL_IRQ_SET 0x04
+#define GPUEB_MBOX_CTL_IRQ_CLR 0x74
+#define GPUEB_MBOX_CTL_RX_STS 0x78
+
+#define GPUEB_MBOX_FULL BIT(0) /* i.e. we've received data */
+#define GPUEB_MBOX_BLOCKED BIT(1) /* i.e. the channel is shutdown */
+
+#define GPUEB_MBOX_MAX_RX_SIZE 32 /* in bytes */
+
+struct mtk_gpueb_mbox {
+ struct device *dev;
+ struct clk *clk;
+ void __iomem *mbox_mmio;
+ void __iomem *mbox_ctl;
+ struct mbox_controller mbox;
+ struct mtk_gpueb_mbox_chan *ch;
+ int irq;
+ const struct mtk_gpueb_mbox_variant *v;
+};
+
+/**
+ * struct mtk_gpueb_mbox_chan - per-channel runtime data
+ * @ebm: pointer to the parent &struct mtk_gpueb_mbox mailbox
+ * @full_name: descriptive name of channel for IRQ subsystem
+ * @num: channel number, starting at 0
+ * @rx_status: signifies whether channel reception is turned off, or full
+ * @c: pointer to the constant &struct mtk_gpueb_mbox_chan_desc channel data
+ */
+struct mtk_gpueb_mbox_chan {
+ struct mtk_gpueb_mbox *ebm;
+ char *full_name;
+ u8 num;
+ atomic_t rx_status;
+ const struct mtk_gpueb_mbox_chan_desc *c;
+};
+
+/**
+ * struct mtk_gpueb_mbox_chan_desc - per-channel constant data
+ * @name: name of this channel
+ * @num: index of this channel, starting at 0
+ * @tx_offset: byte offset measured from mmio base for outgoing data
+ * @tx_len: size, in bytes, of the outgoing data on this channel
+ * @rx_offset: bytes offset measured from mmio base for incoming data
+ * @rx_len: size, in bytes, of the incoming data on this channel
+ */
+struct mtk_gpueb_mbox_chan_desc {
+ const char *name;
+ const u8 num;
+ const u16 tx_offset;
+ const u8 tx_len;
+ const u16 rx_offset;
+ const u8 rx_len;
+};
+
+struct mtk_gpueb_mbox_variant {
+ const u8 num_channels;
+ const struct mtk_gpueb_mbox_chan_desc channels[] __counted_by(num_channels);
+};
+
+/**
+ * mtk_gpueb_mbox_read_rx - read RX buffer from MMIO into channel's RX buffer
+ * @buf: buffer to read into
+ * @chan: pointer to the channel to read
+ */
+static void mtk_gpueb_mbox_read_rx(void *buf, struct mtk_gpueb_mbox_chan *chan)
+{
+ memcpy_fromio(buf, chan->ebm->mbox_mmio + chan->c->rx_offset, chan->c->rx_len);
+}
+
+static irqreturn_t mtk_gpueb_mbox_isr(int irq, void *data)
+{
+ struct mtk_gpueb_mbox_chan *ch = data;
+ u32 rx_sts;
+
+ rx_sts = readl(ch->ebm->mbox_ctl + GPUEB_MBOX_CTL_RX_STS);
+
+ if (rx_sts & BIT(ch->num)) {
+ if (!atomic_cmpxchg(&ch->rx_status, 0, GPUEB_MBOX_FULL | GPUEB_MBOX_BLOCKED))
+ return IRQ_WAKE_THREAD;
+ }
+
+ return IRQ_NONE;
+}
+
+static irqreturn_t mtk_gpueb_mbox_thread(int irq, void *data)
+{
+ struct mtk_gpueb_mbox_chan *ch = data;
+ int status;
+
+ status = atomic_cmpxchg(&ch->rx_status, GPUEB_MBOX_FULL | GPUEB_MBOX_BLOCKED,
+ GPUEB_MBOX_FULL);
+ if (status == (GPUEB_MBOX_FULL | GPUEB_MBOX_BLOCKED)) {
+ u8 buf[GPUEB_MBOX_MAX_RX_SIZE] = {};
+
+ mtk_gpueb_mbox_read_rx(buf, ch);
+ writel(BIT(ch->num), ch->ebm->mbox_ctl + GPUEB_MBOX_CTL_IRQ_CLR);
+ mbox_chan_received_data(&ch->ebm->mbox.chans[ch->num], buf);
+ atomic_set(&ch->rx_status, 0);
+ return IRQ_HANDLED;
+ }
+
+ return IRQ_NONE;
+}
+
+static int mtk_gpueb_mbox_send_data(struct mbox_chan *chan, void *data)
+{
+ struct mtk_gpueb_mbox_chan *ch = chan->con_priv;
+ u32 *values = data;
+ int i;
+
+ if (atomic_read(&ch->rx_status))
+ return -EBUSY;
+
+ /*
+ * We don't want any fancy nonsense, just write the 32-bit values in
+ * order. memcpy_toio/__iowrite32_copy don't work here, as they may use
+ * writes of different sizes or memory ordering characteristics depending
+ * on the architecture, alignment and the current phase of the moon.
+ */
+ for (i = 0; i < ch->c->tx_len; i += 4)
+ writel(values[i / 4], ch->ebm->mbox_mmio + ch->c->tx_offset + i);
+
+ writel(BIT(ch->num), ch->ebm->mbox_ctl + GPUEB_MBOX_CTL_IRQ_SET);
+
+ return 0;
+}
+
+static int mtk_gpueb_mbox_startup(struct mbox_chan *chan)
+{
+ struct mtk_gpueb_mbox_chan *ch = chan->con_priv;
+ int ret;
+
+ atomic_set(&ch->rx_status, 0);
+
+ ret = clk_enable(ch->ebm->clk);
+ if (ret) {
+ dev_err(ch->ebm->dev, "Failed to enable EB clock: %pe\n",
+ ERR_PTR(ret));
+ goto err_block;
+ }
+
+ writel(BIT(ch->num), ch->ebm->mbox_ctl + GPUEB_MBOX_CTL_IRQ_CLR);
+
+ ret = devm_request_threaded_irq(ch->ebm->dev, ch->ebm->irq, mtk_gpueb_mbox_isr,
+ mtk_gpueb_mbox_thread, IRQF_SHARED | IRQF_ONESHOT,
+ ch->full_name, ch);
+ if (ret) {
+ dev_err(ch->ebm->dev, "Failed to request IRQ: %pe\n",
+ ERR_PTR(ret));
+ goto err_unclk;
+ }
+
+ return 0;
+
+err_unclk:
+ clk_disable(ch->ebm->clk);
+err_block:
+ atomic_set(&ch->rx_status, GPUEB_MBOX_BLOCKED);
+
+ return ret;
+}
+
+static void mtk_gpueb_mbox_shutdown(struct mbox_chan *chan)
+{
+ struct mtk_gpueb_mbox_chan *ch = chan->con_priv;
+
+ atomic_set(&ch->rx_status, GPUEB_MBOX_BLOCKED);
+
+ devm_free_irq(ch->ebm->dev, ch->ebm->irq, ch);
+
+ clk_disable(ch->ebm->clk);
+}
+
+static bool mtk_gpueb_mbox_last_tx_done(struct mbox_chan *chan)
+{
+ struct mtk_gpueb_mbox_chan *ch = chan->con_priv;
+
+ return !(readl(ch->ebm->mbox_ctl + GPUEB_MBOX_CTL_TX_STS) & BIT(ch->num));
+}
+
+const struct mbox_chan_ops mtk_gpueb_mbox_ops = {
+ .send_data = mtk_gpueb_mbox_send_data,
+ .startup = mtk_gpueb_mbox_startup,
+ .shutdown = mtk_gpueb_mbox_shutdown,
+ .last_tx_done = mtk_gpueb_mbox_last_tx_done,
+};
+
+static int mtk_gpueb_mbox_probe(struct platform_device *pdev)
+{
+ struct mtk_gpueb_mbox_chan *ch;
+ struct mtk_gpueb_mbox *ebm;
+ unsigned int i;
+
+ ebm = devm_kzalloc(&pdev->dev, sizeof(*ebm), GFP_KERNEL);
+ if (!ebm)
+ return -ENOMEM;
+
+ ebm->dev = &pdev->dev;
+ ebm->v = of_device_get_match_data(ebm->dev);
+
+ ebm->irq = platform_get_irq(pdev, 0);
+ if (ebm->irq < 0)
+ return ebm->irq;
+
+ ebm->clk = devm_clk_get_prepared(ebm->dev, NULL);
+ if (IS_ERR(ebm->clk))
+ return dev_err_probe(ebm->dev, PTR_ERR(ebm->clk),
+ "Failed to get 'eb' clock\n");
+
+ ebm->mbox_mmio = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(ebm->mbox_mmio))
+ return dev_err_probe(ebm->dev, PTR_ERR(ebm->mbox_mmio),
+ "Couldn't map mailbox data registers\n");
+
+ ebm->mbox_ctl = devm_platform_ioremap_resource(pdev, 1);
+ if (IS_ERR(ebm->mbox_ctl))
+ return dev_err_probe(
+ ebm->dev, PTR_ERR(ebm->mbox_ctl),
+ "Couldn't map mailbox control registers\n");
+
+ ebm->ch = devm_kmalloc_array(ebm->dev, ebm->v->num_channels,
+ sizeof(*ebm->ch), GFP_KERNEL);
+ if (!ebm->ch)
+ return -ENOMEM;
+
+ ebm->mbox.chans = devm_kcalloc(ebm->dev, ebm->v->num_channels,
+ sizeof(struct mbox_chan), GFP_KERNEL);
+ if (!ebm->mbox.chans)
+ return -ENOMEM;
+
+ for (i = 0; i < ebm->v->num_channels; i++) {
+ ch = &ebm->ch[i];
+ ch->c = &ebm->v->channels[i];
+ if (ch->c->rx_len > GPUEB_MBOX_MAX_RX_SIZE) {
+ dev_err(ebm->dev, "Channel %s RX size (%d) too large\n",
+ ch->c->name, ch->c->rx_len);
+ return -EINVAL;
+ }
+ ch->full_name = devm_kasprintf(ebm->dev, GFP_KERNEL, "%s:%s",
+ dev_name(ebm->dev), ch->c->name);
+ if (!ch->full_name)
+ return -ENOMEM;
+
+ ch->ebm = ebm;
+ ch->num = i;
+ spin_lock_init(&ebm->mbox.chans[i].lock);
+ ebm->mbox.chans[i].con_priv = ch;
+ atomic_set(&ch->rx_status, GPUEB_MBOX_BLOCKED);
+ }
+
+ ebm->mbox.dev = ebm->dev;
+ ebm->mbox.num_chans = ebm->v->num_channels;
+ ebm->mbox.txdone_poll = true;
+ ebm->mbox.txpoll_period = 0; /* minimum hrtimer interval */
+ ebm->mbox.ops = &mtk_gpueb_mbox_ops;
+
+ dev_set_drvdata(ebm->dev, ebm);
+
+ return devm_mbox_controller_register(ebm->dev, &ebm->mbox);
+}
+
+static const struct mtk_gpueb_mbox_variant mtk_gpueb_mbox_mt8196 = {
+ .num_channels = 12,
+ .channels = {
+ { "fast-dvfs-event", 0, 0x0000, 16, 0x00e0, 16 },
+ { "gpufreq", 1, 0x0010, 32, 0x00f0, 32 },
+ { "sleep", 2, 0x0030, 12, 0x0110, 4 },
+ { "timer", 3, 0x003c, 24, 0x0114, 4 },
+ { "fhctl", 4, 0x0054, 36, 0x0118, 4 },
+ { "ccf", 5, 0x0078, 16, 0x011c, 16 },
+ { "gpumpu", 6, 0x0088, 24, 0x012c, 4 },
+ { "fast-dvfs", 7, 0x00a0, 24, 0x0130, 24 },
+ { "ipir-c-met", 8, 0x00b8, 4, 0x0148, 16 },
+ { "ipis-c-met", 9, 0x00bc, 16, 0x0158, 4 },
+ { "brisket", 10, 0x00cc, 16, 0x015c, 16 },
+ { "ppb", 11, 0x00dc, 4, 0x016c, 4 },
+ },
+};
+
+static const struct of_device_id mtk_gpueb_mbox_of_ids[] = {
+ { .compatible = "mediatek,mt8196-gpueb-mbox", .data = &mtk_gpueb_mbox_mt8196 },
+ { /* Sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, mtk_gpueb_mbox_of_ids);
+
+static struct platform_driver mtk_gpueb_mbox_drv = {
+ .probe = mtk_gpueb_mbox_probe,
+ .driver = {
+ .name = "mtk-gpueb-mbox",
+ .of_match_table = mtk_gpueb_mbox_of_ids,
+ }
+};
+module_platform_driver(mtk_gpueb_mbox_drv);
+
+MODULE_AUTHOR("Nicolas Frattaroli <nicolas.frattaroli@collabora.com>");
+MODULE_DESCRIPTION("MediaTek GPUEB mailbox driver");
+MODULE_LICENSE("GPL");
generated by cgit (git 2.34.1) at 2025-10-09 20:23:24 +0000