mailbox: Add support for QTI CPUCP mailbox controller
authorSibi Sankar <quic_sibis@quicinc.com>
Wed, 12 Jun 2024 12:40:53 +0000 (18:10 +0530)
committerJassi Brar <jassisinghbrar@gmail.com>
Wed, 10 Jul 2024 18:24:55 +0000 (13:24 -0500)
Add support for CPUSS Control Processor (CPUCP) mailbox controller,
this driver enables communication between AP and CPUCP by acting as
a doorbell between them.

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Sibi Sankar <quic_sibis@quicinc.com>
Reviewed-by: Bjorn Andersson <andersson@kernel.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>
MAINTAINERS
drivers/mailbox/Kconfig
drivers/mailbox/Makefile
drivers/mailbox/qcom-cpucp-mbox.c [new file with mode: 0644]

index da5352d..b28f4c6 100644 (file)
@@ -18461,6 +18461,13 @@ S:     Maintained
 F:     Documentation/devicetree/bindings/power/avs/qcom,cpr.yaml
 F:     drivers/pmdomain/qcom/cpr.c
 
+QUALCOMM CPUCP MAILBOX DRIVER
+M:     Sibi Sankar <quic_sibis@quicinc.com>
+L:     linux-arm-msm@vger.kernel.org
+S:     Supported
+F:     Documentation/devicetree/bindings/mailbox/qcom,cpucp-mbox.yaml
+F:     drivers/mailbox/qcom-cpucp-mbox.c
+
 QUALCOMM CPUFREQ DRIVER MSM8996/APQ8096
 M:     Ilia Lin <ilia.lin@kernel.org>
 L:     linux-pm@vger.kernel.org
index 3b8842c..d1f6c75 100644 (file)
@@ -276,6 +276,14 @@ config SPRD_MBOX
          to send message between application processors and MCU. Say Y here if
          you want to build the Spreatrum mailbox controller driver.
 
+config QCOM_CPUCP_MBOX
+       tristate "Qualcomm Technologies, Inc. CPUCP mailbox driver"
+       depends on ARCH_QCOM || (COMPILE_TEST && 64BIT)
+       help
+         Qualcomm Technologies, Inc. CPUSS Control Processor (CPUCP) mailbox
+         controller driver enables communication between AP and CPUCP. Say
+         Y here if you want to build this driver.
+
 config QCOM_IPCC
        tristate "Qualcomm Technologies, Inc. IPCC driver"
        depends on ARCH_QCOM || COMPILE_TEST
index 5cf2f54..3c3c27d 100644 (file)
@@ -61,4 +61,6 @@ obj-$(CONFIG_SUN6I_MSGBOX)    += sun6i-msgbox.o
 
 obj-$(CONFIG_SPRD_MBOX)                += sprd-mailbox.o
 
+obj-$(CONFIG_QCOM_CPUCP_MBOX)  += qcom-cpucp-mbox.o
+
 obj-$(CONFIG_QCOM_IPCC)                += qcom-ipcc.o
diff --git a/drivers/mailbox/qcom-cpucp-mbox.c b/drivers/mailbox/qcom-cpucp-mbox.c
new file mode 100644 (file)
index 0000000..e5437c2
--- /dev/null
@@ -0,0 +1,187 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2024, Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#include <linux/bitops.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/mailbox_controller.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#define APSS_CPUCP_IPC_CHAN_SUPPORTED          3
+#define APSS_CPUCP_MBOX_CMD_OFF                        0x4
+
+/* Tx Registers */
+#define APSS_CPUCP_TX_MBOX_CMD(i)              (0x100 + ((i) * 8))
+
+/* Rx Registers */
+#define APSS_CPUCP_RX_MBOX_CMD(i)              (0x100 + ((i) * 8))
+#define APSS_CPUCP_RX_MBOX_MAP                 0x4000
+#define APSS_CPUCP_RX_MBOX_STAT                        0x4400
+#define APSS_CPUCP_RX_MBOX_CLEAR               0x4800
+#define APSS_CPUCP_RX_MBOX_EN                  0x4c00
+#define APSS_CPUCP_RX_MBOX_CMD_MASK            GENMASK_ULL(63, 0)
+
+/**
+ * struct qcom_cpucp_mbox - Holder for the mailbox driver
+ * @chans:                     The mailbox channel
+ * @mbox:                      The mailbox controller
+ * @tx_base:                   Base address of the CPUCP tx registers
+ * @rx_base:                   Base address of the CPUCP rx registers
+ */
+struct qcom_cpucp_mbox {
+       struct mbox_chan chans[APSS_CPUCP_IPC_CHAN_SUPPORTED];
+       struct mbox_controller mbox;
+       void __iomem *tx_base;
+       void __iomem *rx_base;
+};
+
+static inline int channel_number(struct mbox_chan *chan)
+{
+       return chan - chan->mbox->chans;
+}
+
+static irqreturn_t qcom_cpucp_mbox_irq_fn(int irq, void *data)
+{
+       struct qcom_cpucp_mbox *cpucp = data;
+       u64 status;
+       int i;
+
+       status = readq(cpucp->rx_base + APSS_CPUCP_RX_MBOX_STAT);
+
+       for_each_set_bit(i, (unsigned long *)&status, APSS_CPUCP_IPC_CHAN_SUPPORTED) {
+               u32 val = readl(cpucp->rx_base + APSS_CPUCP_RX_MBOX_CMD(i) + APSS_CPUCP_MBOX_CMD_OFF);
+               struct mbox_chan *chan = &cpucp->chans[i];
+               unsigned long flags;
+
+               /* Provide mutual exclusion with changes to chan->cl */
+               spin_lock_irqsave(&chan->lock, flags);
+               if (chan->cl)
+                       mbox_chan_received_data(chan, &val);
+               writeq(BIT(i), cpucp->rx_base + APSS_CPUCP_RX_MBOX_CLEAR);
+               spin_unlock_irqrestore(&chan->lock, flags);
+       }
+
+       return IRQ_HANDLED;
+}
+
+static int qcom_cpucp_mbox_startup(struct mbox_chan *chan)
+{
+       struct qcom_cpucp_mbox *cpucp = container_of(chan->mbox, struct qcom_cpucp_mbox, mbox);
+       unsigned long chan_id = channel_number(chan);
+       u64 val;
+
+       val = readq(cpucp->rx_base + APSS_CPUCP_RX_MBOX_EN);
+       val |= BIT(chan_id);
+       writeq(val, cpucp->rx_base + APSS_CPUCP_RX_MBOX_EN);
+
+       return 0;
+}
+
+static void qcom_cpucp_mbox_shutdown(struct mbox_chan *chan)
+{
+       struct qcom_cpucp_mbox *cpucp = container_of(chan->mbox, struct qcom_cpucp_mbox, mbox);
+       unsigned long chan_id = channel_number(chan);
+       u64 val;
+
+       val = readq(cpucp->rx_base + APSS_CPUCP_RX_MBOX_EN);
+       val &= ~BIT(chan_id);
+       writeq(val, cpucp->rx_base + APSS_CPUCP_RX_MBOX_EN);
+}
+
+static int qcom_cpucp_mbox_send_data(struct mbox_chan *chan, void *data)
+{
+       struct qcom_cpucp_mbox *cpucp = container_of(chan->mbox, struct qcom_cpucp_mbox, mbox);
+       unsigned long chan_id = channel_number(chan);
+       u32 *val = data;
+
+       writel(*val, cpucp->tx_base + APSS_CPUCP_TX_MBOX_CMD(chan_id) + APSS_CPUCP_MBOX_CMD_OFF);
+
+       return 0;
+}
+
+static const struct mbox_chan_ops qcom_cpucp_mbox_chan_ops = {
+       .startup = qcom_cpucp_mbox_startup,
+       .send_data = qcom_cpucp_mbox_send_data,
+       .shutdown = qcom_cpucp_mbox_shutdown
+};
+
+static int qcom_cpucp_mbox_probe(struct platform_device *pdev)
+{
+       struct device *dev = &pdev->dev;
+       struct qcom_cpucp_mbox *cpucp;
+       struct mbox_controller *mbox;
+       int irq, ret;
+
+       cpucp = devm_kzalloc(dev, sizeof(*cpucp), GFP_KERNEL);
+       if (!cpucp)
+               return -ENOMEM;
+
+       cpucp->rx_base = devm_of_iomap(dev, dev->of_node, 0, NULL);
+       if (IS_ERR(cpucp->rx_base))
+               return PTR_ERR(cpucp->rx_base);
+
+       cpucp->tx_base = devm_of_iomap(dev, dev->of_node, 1, NULL);
+       if (IS_ERR(cpucp->tx_base))
+               return PTR_ERR(cpucp->tx_base);
+
+       writeq(0, cpucp->rx_base + APSS_CPUCP_RX_MBOX_EN);
+       writeq(0, cpucp->rx_base + APSS_CPUCP_RX_MBOX_CLEAR);
+       writeq(0, cpucp->rx_base + APSS_CPUCP_RX_MBOX_MAP);
+
+       irq = platform_get_irq(pdev, 0);
+       if (irq < 0)
+               return irq;
+
+       ret = devm_request_irq(dev, irq, qcom_cpucp_mbox_irq_fn,
+                              IRQF_TRIGGER_HIGH, "apss_cpucp_mbox", cpucp);
+       if (ret < 0)
+               return dev_err_probe(dev, ret, "Failed to register irq: %d\n", irq);
+
+       writeq(APSS_CPUCP_RX_MBOX_CMD_MASK, cpucp->rx_base + APSS_CPUCP_RX_MBOX_MAP);
+
+       mbox = &cpucp->mbox;
+       mbox->dev = dev;
+       mbox->num_chans = APSS_CPUCP_IPC_CHAN_SUPPORTED;
+       mbox->chans = cpucp->chans;
+       mbox->ops = &qcom_cpucp_mbox_chan_ops;
+
+       ret = devm_mbox_controller_register(dev, mbox);
+       if (ret)
+               return dev_err_probe(dev, ret, "Failed to create mailbox\n");
+
+       return 0;
+}
+
+static const struct of_device_id qcom_cpucp_mbox_of_match[] = {
+       { .compatible = "qcom,x1e80100-cpucp-mbox" },
+       {}
+};
+MODULE_DEVICE_TABLE(of, qcom_cpucp_mbox_of_match);
+
+static struct platform_driver qcom_cpucp_mbox_driver = {
+       .probe = qcom_cpucp_mbox_probe,
+       .driver = {
+               .name = "qcom_cpucp_mbox",
+               .of_match_table = qcom_cpucp_mbox_of_match,
+       },
+};
+
+static int __init qcom_cpucp_mbox_init(void)
+{
+       return platform_driver_register(&qcom_cpucp_mbox_driver);
+}
+core_initcall(qcom_cpucp_mbox_init);
+
+static void __exit qcom_cpucp_mbox_exit(void)
+{
+       platform_driver_unregister(&qcom_cpucp_mbox_driver);
+}
+module_exit(qcom_cpucp_mbox_exit);
+
+MODULE_DESCRIPTION("QTI CPUCP MBOX Driver");
+MODULE_LICENSE("GPL");