Re: [PATCH v2 2/3] mailbox: Add support for Qualcomm IPCC

Bjorn Andersson
2020-05-12T22:14:27Z

On Fri 08 May 11:27 PDT 2020, Manivannan Sadhasivam wrote:

> Add support for the Inter-Processor Communication Controller (IPCC)
> block from Qualcomm that coordinates the interrupts (inbound & outbound)
> for Multiprocessor (MPROC), COMPUTE-Level0 (COMPUTE-L0) & COMPUTE-Level1
> (COMPUTE-L1) protocols for the Application Processor Subsystem (APSS).
>
> This driver is modeled as an irqchip+mailbox driver. The irqchip part
> helps in receiving the interrupts from the IPCC clients such as modems,
> DSPs, PCI-E etc... and forwards them to respective entities in APSS.
>
> On the other hand, the mailbox part is used to send interrupts to the IPCC
> clients from the entities of APSS.
>
> Signed-off-by: Raghavendra Rao Ananta <rananta@codeaurora.org>
> Signed-off-by: Venkata Narendra Kumar Gutta <vnkgutta@codeaurora.org>
> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> [mani: moved to mailbox, added static mbox channels and cleanups]
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

This looks nice now!

Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>

Regards,
Bjorn

> ---
> drivers/mailbox/Kconfig | 10 ++
> drivers/mailbox/Makefile | 2 +
> drivers/mailbox/qcom-ipcc.c | 286 ++++++++++++++++++++++++++++++++++++
> 3 files changed, 298 insertions(+)
> create mode 100644 drivers/mailbox/qcom-ipcc.c
>
> diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
> index 5a577a6734cf..8e1ebdbf8eab 100644
> --- a/drivers/mailbox/Kconfig
> +++ b/drivers/mailbox/Kconfig
> @@ -236,4 +236,14 @@ config SUN6I_MSGBOX
> various Allwinner SoCs. This mailbox is used for communication
> between the application CPUs and the power management coprocessor.
>
> +config QCOM_IPCC
> + bool "Qualcomm Technologies, Inc. IPCC driver"
> + depends on ARCH_QCOM || COMPILE_TEST
> + help
> + Qualcomm Technologies, Inc. Inter-Processor Communication Controller
> + (IPCC) driver for MSM devices. The driver provides mailbox support for
> + sending interrupts to the clients. On the other hand, the driver also
> + acts as an interrupt controller for receiving interrupts from clients.
> + Say Y here if you want to build this driver.
> +
> endif
> diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
> index 2e4364ef5c47..20b66b2219aa 100644
> --- a/drivers/mailbox/Makefile
> +++ b/drivers/mailbox/Makefile
> @@ -50,3 +50,5 @@ obj-$(CONFIG_MTK_CMDQ_MBOX) += mtk-cmdq-mailbox.o
> obj-$(CONFIG_ZYNQMP_IPI_MBOX) += zynqmp-ipi-mailbox.o
>
> obj-$(CONFIG_SUN6I_MSGBOX) += sun6i-msgbox.o
> +
> +obj-$(CONFIG_QCOM_IPCC) += qcom-ipcc.o
> diff --git a/drivers/mailbox/qcom-ipcc.c b/drivers/mailbox/qcom-ipcc.c
> new file mode 100644
> index 000000000000..2d13c72944c6
> --- /dev/null
> +++ b/drivers/mailbox/qcom-ipcc.c
> @@ -0,0 +1,286 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2018-2020, The Linux Foundation. All rights reserved.
> + */
> +
> +#include <linux/bitfield.h>
> +#include <linux/interrupt.h>
> +#include <linux/irq.h>
> +#include <linux/irqdomain.h>
> +#include <linux/mailbox_controller.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +
> +#include <dt-bindings/mailbox/qcom-ipcc.h>
> +
> +#define IPCC_MBOX_MAX_CHAN 48
> +
> +/* IPCC Register offsets */
> +#define IPCC_REG_SEND_ID 0x0c
> +#define IPCC_REG_RECV_ID 0x10
> +#define IPCC_REG_RECV_SIGNAL_ENABLE 0x14
> +#define IPCC_REG_RECV_SIGNAL_DISABLE 0x18
> +#define IPCC_REG_RECV_SIGNAL_CLEAR 0x1c
> +#define IPCC_REG_CLIENT_CLEAR 0x38
> +
> +#define IPCC_SIGNAL_ID_MASK GENMASK(15, 0)
> +#define IPCC_CLIENT_ID_MASK GENMASK(31, 16)
> +
> +#define IPCC_NO_PENDING_IRQ GENMASK(31, 0)
> +
> +/**
> + * struct qcom_ipcc_chan_info - Per-mailbox-channel info
> + * @client_id: The client-id to which the interrupt has to be triggered
> + * @signal_id: The signal-id to which the interrupt has to be triggered
> + */
> +struct qcom_ipcc_chan_info {
> + u16 client_id;
> + u16 signal_id;
> +};
> +
> +/**
> + * struct qcom_ipcc - Holder for the mailbox driver
> + * @dev: Device associated with this instance
> + * @base: Base address of the IPCC frame associated to APSS
> + * @irq_domain: The irq_domain associated with this instance
> + * @chan: The mailbox channels array
> + * @mchan: The per-mailbox channel info array
> + * @mbox: The mailbox controller
> + * @irq: Summary irq
> + */
> +struct qcom_ipcc {
> + struct device *dev;
> + void __iomem *base;
> + struct irq_domain *irq_domain;
> + struct mbox_chan chan[IPCC_MBOX_MAX_CHAN];
> + struct qcom_ipcc_chan_info mchan[IPCC_MBOX_MAX_CHAN];
> + struct mbox_controller mbox;
> + int irq;
> +};
> +
> +static inline struct qcom_ipcc *to_qcom_ipcc(struct mbox_controller *mbox)
> +{
> + return container_of(mbox, struct qcom_ipcc, mbox);
> +}
> +
> +static inline u32 qcom_ipcc_get_hwirq(u16 client_id, u16 signal_id)
> +{
> + return FIELD_PREP(IPCC_CLIENT_ID_MASK, client_id) |
> + FIELD_PREP(IPCC_SIGNAL_ID_MASK, signal_id);
> +}
> +
> +static irqreturn_t qcom_ipcc_irq_fn(int irq, void *data)
> +{
> + struct qcom_ipcc *ipcc = data;
> + u32 hwirq;
> + int virq;
> +
> + for (;;) {
> + hwirq = readl(ipcc->base + IPCC_REG_RECV_ID);
> + if (hwirq == IPCC_NO_PENDING_IRQ)
> + break;
> +
> + virq = irq_find_mapping(ipcc->irq_domain, hwirq);
> + writel(hwirq, ipcc->base + IPCC_REG_RECV_SIGNAL_CLEAR);
> + generic_handle_irq(virq);
> + }
> +
> + return IRQ_HANDLED;
> +}
> +
> +static void qcom_ipcc_mask_irq(struct irq_data *irqd)
> +{
> + struct qcom_ipcc *ipcc = irq_data_get_irq_chip_data(irqd);
> + irq_hw_number_t hwirq = irqd_to_hwirq(irqd);
> +
> + writel(hwirq, ipcc->base + IPCC_REG_RECV_SIGNAL_DISABLE);
> +}
> +
> +static void qcom_ipcc_unmask_irq(struct irq_data *irqd)
> +{
> + struct qcom_ipcc *ipcc = irq_data_get_irq_chip_data(irqd);
> + irq_hw_number_t hwirq = irqd_to_hwirq(irqd);
> +
> + writel(hwirq, ipcc->base + IPCC_REG_RECV_SIGNAL_ENABLE);
> +}
> +
> +static struct irq_chip qcom_ipcc_irq_chip = {
> + .name = "ipcc",
> + .irq_mask = qcom_ipcc_mask_irq,
> + .irq_unmask = qcom_ipcc_unmask_irq,
> + .flags = IRQCHIP_SKIP_SET_WAKE,
> +};
> +
> +static int qcom_ipcc_domain_map(struct irq_domain *d, unsigned int irq,
> + irq_hw_number_t hw)
> +{
> + struct qcom_ipcc *ipcc = d->host_data;
> +
> + irq_set_chip_and_handler(irq, &qcom_ipcc_irq_chip, handle_level_irq);
> + irq_set_chip_data(irq, ipcc);
> + irq_set_noprobe(irq);
> +
> + return 0;
> +}
> +
> +static int qcom_ipcc_domain_xlate(struct irq_domain *d,
> + struct device_node *node, const u32 *intspec,
> + unsigned int intsize,
> + unsigned long *out_hwirq,
> + unsigned int *out_type)
> +{
> + if (intsize != 3)
> + return -EINVAL;
> +
> + *out_hwirq = qcom_ipcc_get_hwirq(intspec[0], intspec[1]);
> + *out_type = intspec[2] & IRQ_TYPE_SENSE_MASK;
> +
> + return 0;
> +}
> +
> +static const struct irq_domain_ops qcom_ipcc_irq_ops = {
> + .map = qcom_ipcc_domain_map,
> + .xlate = qcom_ipcc_domain_xlate,
> +};
> +
> +static int qcom_ipcc_mbox_send_data(struct mbox_chan *chan, void *data)
> +{
> + struct qcom_ipcc *ipcc = to_qcom_ipcc(chan->mbox);
> + struct qcom_ipcc_chan_info *mchan = chan->con_priv;
> + u32 hwirq;
> +
> + hwirq = qcom_ipcc_get_hwirq(mchan->client_id, mchan->signal_id);
> + writel(hwirq, ipcc->base + IPCC_REG_SEND_ID);
> +
> + return 0;
> +}
> +
> +static struct mbox_chan *qcom_ipcc_mbox_xlate(struct mbox_controller *mbox,
> + const struct of_phandle_args *ph)
> +{
> + struct qcom_ipcc *ipcc = to_qcom_ipcc(mbox);
> + struct qcom_ipcc_chan_info *mchan;
> + struct mbox_chan *chan;
> + unsigned int i;
> +
> + if (ph->args_count != 2)
> + return ERR_PTR(-EINVAL);
> +
> + for (i = 0; i < IPCC_MBOX_MAX_CHAN; i++) {
> + chan = &ipcc->chan[i];
> + if (!chan->con_priv) {
> + mchan = &ipcc->mchan[i];
> + mchan->client_id = ph->args[0];
> + mchan->signal_id = ph->args[1];
> + chan->con_priv = mchan;
> + break;
> + }
> +
> + chan = NULL;
> + }
> +
> + return chan ?: ERR_PTR(-EBUSY);
> +}
> +
> +static const struct mbox_chan_ops ipcc_mbox_chan_ops = {
> + .send_data = qcom_ipcc_mbox_send_data,
> +};
> +
> +static int qcom_ipcc_setup_mbox(struct qcom_ipcc *ipcc)
> +{
> + struct mbox_controller *mbox;
> + struct device *dev = ipcc->dev;
> +
> + mbox = &ipcc->mbox;
> + mbox->dev = dev;
> + mbox->num_chans = IPCC_MBOX_MAX_CHAN;
> + mbox->chans = ipcc->chan;
> + mbox->ops = &ipcc_mbox_chan_ops;
> + mbox->of_xlate = qcom_ipcc_mbox_xlate;
> + mbox->txdone_irq = false;
> + mbox->txdone_poll = false;
> +
> + return devm_mbox_controller_register(dev, mbox);
> +}
> +
> +static int qcom_ipcc_probe(struct platform_device *pdev)
> +{
> + struct qcom_ipcc *ipcc;
> + int ret;
> +
> + ipcc = devm_kzalloc(&pdev->dev, sizeof(*ipcc), GFP_KERNEL);
> + if (!ipcc)
> + return -ENOMEM;
> +
> + ipcc->dev = &pdev->dev;
> +
> + ipcc->base = devm_platform_ioremap_resource(pdev, 0);
> + if (IS_ERR(ipcc->base))
> + return PTR_ERR(ipcc->base);
> +
> + ipcc->irq = platform_get_irq(pdev, 0);
> + if (ipcc->irq < 0)
> + return ipcc->irq;
> +
> + ipcc->irq_domain = irq_domain_add_tree(pdev->dev.of_node,
> + &qcom_ipcc_irq_ops, ipcc);
> + if (!ipcc->irq_domain)
> + return -ENOMEM;
> +
> + ret = qcom_ipcc_setup_mbox(ipcc);
> + if (ret)
> + goto err_mbox;
> +
> + ret = devm_request_irq(&pdev->dev, ipcc->irq, qcom_ipcc_irq_fn,
> + IRQF_TRIGGER_HIGH, "ipcc", ipcc);
> + if (ret < 0) {
> + dev_err(&pdev->dev, "Failed to register the irq: %d\n", ret);
> + goto err_mbox;
> + }
> +
> + enable_irq_wake(ipcc->irq);
> + platform_set_drvdata(pdev, ipcc);
> +
> + return 0;
> +
> +err_mbox:
> + irq_domain_remove(ipcc->irq_domain);
> +
> + return ret;
> +}
> +
> +static int qcom_ipcc_remove(struct platform_device *pdev)
> +{
> + struct qcom_ipcc *ipcc = platform_get_drvdata(pdev);
> +
> + disable_irq_wake(ipcc->irq);
> + irq_domain_remove(ipcc->irq_domain);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id qcom_ipcc_of_match[] = {
> + { .compatible = "qcom,ipcc"},
> + {}
> +};
> +MODULE_DEVICE_TABLE(of, qcom_ipcc_of_match);
> +
> +static struct platform_driver qcom_ipcc_driver = {
> + .probe = qcom_ipcc_probe,
> + .remove = qcom_ipcc_remove,
> + .driver = {
> + .name = "qcom-ipcc",
> + .of_match_table = qcom_ipcc_of_match,
> + },
> +};
> +
> +static int __init qcom_ipcc_init(void)
> +{
> + return platform_driver_register(&qcom_ipcc_driver);
> +}
> +arch_initcall(qcom_ipcc_init);
> +
> +MODULE_AUTHOR("Venkata Narendra Kumar Gutta <vnkgutta@codeaurora.org>");
> +MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>");
> +MODULE_DESCRIPTION("Qualcomm Technologies, Inc. IPCC driver");
> +MODULE_LICENSE("GPL v2");
> --
> 2.17.1
>