From: Samuel Holland <samuel@sholland.org>
To: Maxime Ripard <maxime.ripard@bootlin.com>,
Chen-Yu Tsai <wens@csie.org>,
Jassi Brar <jassisinghbrar@gmail.com>,
Michael Turquette <mturquette@baylibre.com>,
Stephen Boyd <sboyd@kernel.org>, Rob Herring <robh+dt@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Corentin Labbe <clabbe.montjoie@gmail.com>,
Vasily Khoruzhick <anarsoul@gmail.com>
Cc: devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-sunxi@googlegroups.com,
Samuel Holland <samuel@sholland.org>
Subject: [PATCH v4 04/10] mailbox: sunxi-msgbox: Add a new mailbox driver
Date: Mon, 19 Aug 2019 22:23:05 -0500 [thread overview]
Message-ID: <20190820032311.6506-5-samuel@sholland.org> (raw)
In-Reply-To: <20190820032311.6506-1-samuel@sholland.org>
Allwinner sun8i, sun9i, and sun50i SoCs contain a hardware message box
used for communication between the ARM CPUs and the ARISC management
coprocessor. The hardware contains 8 unidirectional 4-message FIFOs.
Add a driver for it, so it can be used for SCPI or other communication
protocols.
Signed-off-by: Samuel Holland <samuel@sholland.org>
---
drivers/mailbox/Kconfig | 10 +
drivers/mailbox/Makefile | 2 +
drivers/mailbox/sunxi-msgbox.c | 323 +++++++++++++++++++++++++++++++++
3 files changed, 335 insertions(+)
create mode 100644 drivers/mailbox/sunxi-msgbox.c
diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
index ab4eb750bbdd..57d12936175e 100644
--- a/drivers/mailbox/Kconfig
+++ b/drivers/mailbox/Kconfig
@@ -227,4 +227,14 @@ config ZYNQMP_IPI_MBOX
message to the IPI buffer and will access the IPI control
registers to kick the other processor or enquire status.
+config SUNXI_MSGBOX
+ tristate "Allwinner sunxi Message Box"
+ depends on ARCH_SUNXI || COMPILE_TEST
+ default ARCH_SUNXI
+ help
+ Mailbox implementation for the hardware message box present in
+ Allwinner sun8i, sun9i, and sun50i SoCs. The hardware message box is
+ used for communication between the application CPUs and the power
+ management coprocessor.
+
endif
diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
index c22fad6f696b..bec2d50b0976 100644
--- a/drivers/mailbox/Makefile
+++ b/drivers/mailbox/Makefile
@@ -48,3 +48,5 @@ obj-$(CONFIG_STM32_IPCC) += stm32-ipcc.o
obj-$(CONFIG_MTK_CMDQ_MBOX) += mtk-cmdq-mailbox.o
obj-$(CONFIG_ZYNQMP_IPI_MBOX) += zynqmp-ipi-mailbox.o
+
+obj-$(CONFIG_SUNXI_MSGBOX) += sunxi-msgbox.o
diff --git a/drivers/mailbox/sunxi-msgbox.c b/drivers/mailbox/sunxi-msgbox.c
new file mode 100644
index 000000000000..29a5101a5390
--- /dev/null
+++ b/drivers/mailbox/sunxi-msgbox.c
@@ -0,0 +1,323 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Copyright (c) 2017-2019 Samuel Holland <samuel@sholland.org>
+
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/mailbox_controller.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+#include <linux/spinlock.h>
+
+#define NUM_CHANS 8
+
+#define CTRL_REG(n) (0x0000 + 0x4 * ((n) / 4))
+#define CTRL_RX(n) BIT(0 + 8 * ((n) % 4))
+#define CTRL_TX(n) BIT(4 + 8 * ((n) % 4))
+
+#define REMOTE_IRQ_EN_REG 0x0040
+#define REMOTE_IRQ_STAT_REG 0x0050
+#define LOCAL_IRQ_EN_REG 0x0060
+#define LOCAL_IRQ_STAT_REG 0x0070
+
+#define RX_IRQ(n) BIT(0 + 2 * (n))
+#define RX_IRQ_MASK 0x5555
+#define TX_IRQ(n) BIT(1 + 2 * (n))
+#define TX_IRQ_MASK 0xaaaa
+
+#define FIFO_STAT_REG(n) (0x0100 + 0x4 * (n))
+#define FIFO_STAT_MASK GENMASK(0, 0)
+
+#define MSG_STAT_REG(n) (0x0140 + 0x4 * (n))
+#define MSG_STAT_MASK GENMASK(2, 0)
+
+#define MSG_DATA_REG(n) (0x0180 + 0x4 * (n))
+
+#define mbox_dbg(mbox, ...) dev_dbg((mbox)->controller.dev, __VA_ARGS__)
+
+struct sunxi_msgbox {
+ struct mbox_controller controller;
+ struct clk *clk;
+ spinlock_t lock;
+ void __iomem *regs;
+};
+
+static bool sunxi_msgbox_last_tx_done(struct mbox_chan *chan);
+static bool sunxi_msgbox_peek_data(struct mbox_chan *chan);
+
+static inline int channel_number(struct mbox_chan *chan)
+{
+ return chan - chan->mbox->chans;
+}
+
+static inline struct sunxi_msgbox *channel_to_msgbox(struct mbox_chan *chan)
+{
+ return chan->con_priv;
+}
+
+static irqreturn_t sunxi_msgbox_irq(int irq, void *dev_id)
+{
+ struct sunxi_msgbox *mbox = dev_id;
+ uint32_t status;
+ int n;
+
+ /* Only examine channels that are currently enabled. */
+ status = readl(mbox->regs + LOCAL_IRQ_EN_REG) &
+ readl(mbox->regs + LOCAL_IRQ_STAT_REG);
+
+ if (!(status & RX_IRQ_MASK))
+ return IRQ_NONE;
+
+ for (n = 0; n < NUM_CHANS; ++n) {
+ struct mbox_chan *chan = &mbox->controller.chans[n];
+
+ if (!(status & RX_IRQ(n)))
+ continue;
+
+ while (sunxi_msgbox_peek_data(chan)) {
+ uint32_t msg = readl(mbox->regs + MSG_DATA_REG(n));
+
+ mbox_dbg(mbox, "Channel %d received 0x%08x\n", n, msg);
+ mbox_chan_received_data(chan, &msg);
+ }
+
+ /* The IRQ can be cleared only once the FIFO is empty. */
+ writel(RX_IRQ(n), mbox->regs + LOCAL_IRQ_STAT_REG);
+ }
+
+ return IRQ_HANDLED;
+}
+
+static int sunxi_msgbox_send_data(struct mbox_chan *chan, void *data)
+{
+ struct sunxi_msgbox *mbox = channel_to_msgbox(chan);
+ int n = channel_number(chan);
+ uint32_t msg = *(uint32_t *)data;
+
+ /* Using a channel backwards gets the hardware into a bad state. */
+ if (WARN_ON_ONCE(!(readl(mbox->regs + CTRL_REG(n)) & CTRL_TX(n))))
+ return 0;
+
+ /* We cannot post a new message if the FIFO is full. */
+ if (readl(mbox->regs + FIFO_STAT_REG(n)) & FIFO_STAT_MASK) {
+ mbox_dbg(mbox, "Channel %d busy sending 0x%08x\n", n, msg);
+ return -EBUSY;
+ }
+
+ writel(msg, mbox->regs + MSG_DATA_REG(n));
+ mbox_dbg(mbox, "Channel %d sent 0x%08x\n", n, msg);
+
+ return 0;
+}
+
+static int sunxi_msgbox_startup(struct mbox_chan *chan)
+{
+ struct sunxi_msgbox *mbox = channel_to_msgbox(chan);
+ int n = channel_number(chan);
+
+ /* The coprocessor is responsible for setting channel directions. */
+ if (readl(mbox->regs + CTRL_REG(n)) & CTRL_RX(n)) {
+ /* Flush the receive FIFO. */
+ while (sunxi_msgbox_peek_data(chan))
+ readl(mbox->regs + MSG_DATA_REG(n));
+ writel(RX_IRQ(n), mbox->regs + LOCAL_IRQ_STAT_REG);
+
+ /* Enable the receive IRQ. */
+ spin_lock(&mbox->lock);
+ writel(readl(mbox->regs + LOCAL_IRQ_EN_REG) | RX_IRQ(n),
+ mbox->regs + LOCAL_IRQ_EN_REG);
+ spin_unlock(&mbox->lock);
+ }
+
+ mbox_dbg(mbox, "Channel %d startup complete\n", n);
+
+ return 0;
+}
+
+static void sunxi_msgbox_shutdown(struct mbox_chan *chan)
+{
+ struct sunxi_msgbox *mbox = channel_to_msgbox(chan);
+ int n = channel_number(chan);
+
+ if (readl(mbox->regs + CTRL_REG(n)) & CTRL_RX(n)) {
+ /* Disable the receive IRQ. */
+ spin_lock(&mbox->lock);
+ writel(readl(mbox->regs + LOCAL_IRQ_EN_REG) & ~RX_IRQ(n),
+ mbox->regs + LOCAL_IRQ_EN_REG);
+ spin_unlock(&mbox->lock);
+
+ /* Attempt to flush the FIFO until the IRQ is cleared. */
+ do {
+ while (sunxi_msgbox_peek_data(chan))
+ readl(mbox->regs + MSG_DATA_REG(n));
+ writel(RX_IRQ(n), mbox->regs + LOCAL_IRQ_STAT_REG);
+ } while (readl(mbox->regs + LOCAL_IRQ_STAT_REG) & RX_IRQ(n));
+ }
+
+ mbox_dbg(mbox, "Channel %d shutdown complete\n", n);
+}
+
+static bool sunxi_msgbox_last_tx_done(struct mbox_chan *chan)
+{
+ struct sunxi_msgbox *mbox = channel_to_msgbox(chan);
+ int n = channel_number(chan);
+
+ /*
+ * The hardware allows snooping on the remote user's IRQ statuses.
+ * We consider a message to be acknowledged only once the receive IRQ
+ * for that channel is cleared. Since the receive IRQ for a channel
+ * cannot be cleared until the FIFO for that channel is empty, this
+ * ensures that the message has actually been read. It also gives the
+ * recipient an opportunity to perform minimal processing before
+ * acknowledging the message.
+ */
+ return !(readl(mbox->regs + REMOTE_IRQ_STAT_REG) & RX_IRQ(n));
+}
+
+static bool sunxi_msgbox_peek_data(struct mbox_chan *chan)
+{
+ struct sunxi_msgbox *mbox = channel_to_msgbox(chan);
+ int n = channel_number(chan);
+
+ return readl(mbox->regs + MSG_STAT_REG(n)) & MSG_STAT_MASK;
+}
+
+static const struct mbox_chan_ops sunxi_msgbox_chan_ops = {
+ .send_data = sunxi_msgbox_send_data,
+ .startup = sunxi_msgbox_startup,
+ .shutdown = sunxi_msgbox_shutdown,
+ .last_tx_done = sunxi_msgbox_last_tx_done,
+ .peek_data = sunxi_msgbox_peek_data,
+};
+
+static int sunxi_msgbox_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct mbox_chan *chans;
+ struct reset_control *reset;
+ struct resource *res;
+ struct sunxi_msgbox *mbox;
+ int i, ret;
+
+ mbox = devm_kzalloc(dev, sizeof(*mbox), GFP_KERNEL);
+ if (!mbox)
+ return -ENOMEM;
+
+ chans = devm_kcalloc(dev, NUM_CHANS, sizeof(*chans), GFP_KERNEL);
+ if (!chans)
+ return -ENOMEM;
+
+ for (i = 0; i < NUM_CHANS; ++i)
+ chans[i].con_priv = mbox;
+
+ mbox->clk = devm_clk_get(dev, NULL);
+ if (IS_ERR(mbox->clk)) {
+ ret = PTR_ERR(mbox->clk);
+ dev_err(dev, "Failed to get clock: %d\n", ret);
+ return ret;
+ }
+
+ ret = clk_prepare_enable(mbox->clk);
+ if (ret) {
+ dev_err(dev, "Failed to enable clock: %d\n", ret);
+ return ret;
+ }
+
+ reset = devm_reset_control_get(dev, NULL);
+ if (IS_ERR(reset)) {
+ ret = PTR_ERR(reset);
+ dev_err(dev, "Failed to get reset control: %d\n", ret);
+ goto err_disable_unprepare;
+ }
+
+ ret = reset_control_deassert(reset);
+ if (ret) {
+ dev_err(dev, "Failed to deassert reset: %d\n", ret);
+ goto err_disable_unprepare;
+ }
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ ret = -ENODEV;
+ goto err_disable_unprepare;
+ }
+
+ mbox->regs = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(mbox->regs)) {
+ ret = PTR_ERR(mbox->regs);
+ dev_err(dev, "Failed to map MMIO resource: %d\n", ret);
+ goto err_disable_unprepare;
+ }
+
+ /* Disable all IRQs for this end of the msgbox. */
+ writel(0, mbox->regs + LOCAL_IRQ_EN_REG);
+
+ ret = devm_request_irq(dev, irq_of_parse_and_map(dev->of_node, 0),
+ sunxi_msgbox_irq, 0, dev_name(dev), mbox);
+ if (ret) {
+ dev_err(dev, "Failed to register IRQ handler: %d\n", ret);
+ goto err_disable_unprepare;
+ }
+
+ mbox->controller.dev = dev;
+ mbox->controller.ops = &sunxi_msgbox_chan_ops;
+ mbox->controller.chans = chans;
+ mbox->controller.num_chans = NUM_CHANS;
+ mbox->controller.txdone_irq = false;
+ mbox->controller.txdone_poll = true;
+ mbox->controller.txpoll_period = 5;
+
+ spin_lock_init(&mbox->lock);
+ platform_set_drvdata(pdev, mbox);
+
+ ret = mbox_controller_register(&mbox->controller);
+ if (ret) {
+ dev_err(dev, "Failed to register controller: %d\n", ret);
+ goto err_disable_unprepare;
+ }
+
+ return 0;
+
+err_disable_unprepare:
+ clk_disable_unprepare(mbox->clk);
+
+ return ret;
+}
+
+static int sunxi_msgbox_remove(struct platform_device *pdev)
+{
+ struct sunxi_msgbox *mbox = platform_get_drvdata(pdev);
+
+ mbox_controller_unregister(&mbox->controller);
+ clk_disable_unprepare(mbox->clk);
+
+ return 0;
+}
+
+static const struct of_device_id sunxi_msgbox_of_match[] = {
+ { .compatible = "allwinner,sun6i-a31-msgbox", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, sunxi_msgbox_of_match);
+
+static struct platform_driver sunxi_msgbox_driver = {
+ .driver = {
+ .name = "sunxi-msgbox",
+ .of_match_table = sunxi_msgbox_of_match,
+ },
+ .probe = sunxi_msgbox_probe,
+ .remove = sunxi_msgbox_remove,
+};
+module_platform_driver(sunxi_msgbox_driver);
+
+MODULE_AUTHOR("Samuel Holland <samuel@sholland.org>");
+MODULE_DESCRIPTION("Allwinner sunxi Message Box");
+MODULE_LICENSE("GPL v2");
--
2.21.0
next prev parent reply other threads:[~2019-08-20 3:23 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-20 3:23 [PATCH v4 00/10] Allwinner sunxi message box support Samuel Holland
2019-08-20 3:23 ` [PATCH v4 01/10] clk: sunxi-ng: Mark msgbox clocks as critical Samuel Holland
2019-08-20 3:23 ` [PATCH v4 02/10] clk: sunxi-ng: Mark AR100 " Samuel Holland
2019-08-20 7:11 ` Maxime Ripard
2019-08-20 13:02 ` Samuel Holland
2019-08-21 12:24 ` Maxime Ripard
2019-09-05 18:56 ` Stephen Boyd
2019-08-20 3:23 ` [PATCH v4 03/10] dt-bindings: mailbox: Add a sunxi message box binding Samuel Holland
2019-08-20 7:14 ` Maxime Ripard
2019-08-20 13:04 ` Samuel Holland
2019-08-21 12:07 ` Maxime Ripard
2019-08-20 3:23 ` Samuel Holland [this message]
2019-08-20 8:27 ` [PATCH v4 04/10] mailbox: sunxi-msgbox: Add a new mailbox driver Maxime Ripard
2019-08-20 11:18 ` Ondřej Jirman
2019-08-20 13:07 ` Samuel Holland
2019-08-20 13:34 ` Ondřej Jirman
2019-08-21 12:30 ` Maxime Ripard
2019-08-20 3:23 ` [PATCH v4 05/10] ARM: dts: sunxi: a80: Add msgbox node Samuel Holland
2019-08-20 8:15 ` Maxime Ripard
2019-08-20 13:17 ` Samuel Holland
2019-08-23 14:56 ` Maxime Ripard
2019-08-20 3:23 ` [PATCH v4 06/10] ARM: dts: sunxi: a83t: " Samuel Holland
2019-08-20 3:23 ` [PATCH v4 07/10] ARM: dts: sunxi: h3/h5: " Samuel Holland
2019-08-20 3:23 ` [PATCH v4 08/10] arm64: dts: allwinner: a64: " Samuel Holland
2019-08-20 3:23 ` [PATCH v4 09/10] arm64: dts: allwinner: h6: " Samuel Holland
2019-08-20 3:23 ` [PATCH v4 10/10] [DO NOT MERGE] drivers: firmware: msgbox demo Samuel Holland
2019-09-09 3:22 ` [PATCH v4 00/10] Allwinner sunxi message box support Ondřej Jirman
2019-09-09 3:54 ` Samuel Holland
2019-09-09 12:36 ` Ondřej Jirman
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190820032311.6506-5-samuel@sholland.org \
--to=samuel@sholland.org \
--cc=anarsoul@gmail.com \
--cc=clabbe.montjoie@gmail.com \
--cc=devicetree@vger.kernel.org \
--cc=jassisinghbrar@gmail.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-clk@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-sunxi@googlegroups.com \
--cc=mark.rutland@arm.com \
--cc=maxime.ripard@bootlin.com \
--cc=mturquette@baylibre.com \
--cc=robh+dt@kernel.org \
--cc=sboyd@kernel.org \
--cc=wens@csie.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).