drivers/mailbox/qcom-cpucp-mbox.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2024, Qualcomm Innovation Center, Inc. All rights reserved.
   4  */
   5
   6 #include <linux/bitops.h>
   7 #include <linux/interrupt.h>
   8 #include <linux/io.h>
   9 #include <linux/irq.h>
  10 #include <linux/irqdomain.h>
  11 #include <linux/mailbox_controller.h>
  12 #include <linux/module.h>
  13 #include <linux/platform_device.h>
  14
  15 #define APSS_CPUCP_IPC_CHAN_SUPPORTED           3
  16 #define APSS_CPUCP_MBOX_CMD_OFF                 0x4
  17
  18 /* Tx Registers */
  19 #define APSS_CPUCP_TX_MBOX_CMD(i)               (0x100 + ((i) * 8))
  20
  21 /* Rx Registers */
  22 #define APSS_CPUCP_RX_MBOX_CMD(i)               (0x100 + ((i) * 8))
  23 #define APSS_CPUCP_RX_MBOX_MAP                  0x4000
  24 #define APSS_CPUCP_RX_MBOX_STAT                 0x4400
  25 #define APSS_CPUCP_RX_MBOX_CLEAR                0x4800
  26 #define APSS_CPUCP_RX_MBOX_EN                   0x4c00
  27 #define APSS_CPUCP_RX_MBOX_CMD_MASK             GENMASK_ULL(63, 0)
  28
  29 /**
  30  * struct qcom_cpucp_mbox - Holder for the mailbox driver
  31  * @chans:                      The mailbox channel
  32  * @mbox:                       The mailbox controller
  33  * @tx_base:                    Base address of the CPUCP tx registers
  34  * @rx_base:                    Base address of the CPUCP rx registers
  35  */
  36 struct qcom_cpucp_mbox {
  37         struct mbox_chan chans[APSS_CPUCP_IPC_CHAN_SUPPORTED];
  38         struct mbox_controller mbox;
  39         void __iomem *tx_base;
  40         void __iomem *rx_base;
  41 };
  42
  43 static inline int channel_number(struct mbox_chan *chan)
  44 {
  45         return chan - chan->mbox->chans;
  46 }
  47
  48 static irqreturn_t qcom_cpucp_mbox_irq_fn(int irq, void *data)
  49 {
  50         struct qcom_cpucp_mbox *cpucp = data;
  51         u64 status;
  52         int i;
  53
  54         status = readq(cpucp->rx_base + APSS_CPUCP_RX_MBOX_STAT);
  55
  56         for_each_set_bit(i, (unsigned long *)&status, APSS_CPUCP_IPC_CHAN_SUPPORTED) {
  57                 u32 val = readl(cpucp->rx_base + APSS_CPUCP_RX_MBOX_CMD(i) + APSS_CPUCP_MBOX_CMD_OFF);
  58                 struct mbox_chan *chan = &cpucp->chans[i];
  59                 unsigned long flags;
  60
  61                 /* Provide mutual exclusion with changes to chan->cl */
  62                 spin_lock_irqsave(&chan->lock, flags);
  63                 if (chan->cl)
  64                         mbox_chan_received_data(chan, &val);
  65                 writeq(BIT(i), cpucp->rx_base + APSS_CPUCP_RX_MBOX_CLEAR);
  66                 spin_unlock_irqrestore(&chan->lock, flags);
  67         }
  68
  69         return IRQ_HANDLED;
  70 }
  71
  72 static int qcom_cpucp_mbox_startup(struct mbox_chan *chan)
  73 {
  74         struct qcom_cpucp_mbox *cpucp = container_of(chan->mbox, struct qcom_cpucp_mbox, mbox);
  75         unsigned long chan_id = channel_number(chan);
  76         u64 val;
  77
  78         val = readq(cpucp->rx_base + APSS_CPUCP_RX_MBOX_EN);
  79         val |= BIT(chan_id);
  80         writeq(val, cpucp->rx_base + APSS_CPUCP_RX_MBOX_EN);
  81
  82         return 0;
  83 }
  84
  85 static void qcom_cpucp_mbox_shutdown(struct mbox_chan *chan)
  86 {
  87         struct qcom_cpucp_mbox *cpucp = container_of(chan->mbox, struct qcom_cpucp_mbox, mbox);
  88         unsigned long chan_id = channel_number(chan);
  89         u64 val;
  90
  91         val = readq(cpucp->rx_base + APSS_CPUCP_RX_MBOX_EN);
  92         val &= ~BIT(chan_id);
  93         writeq(val, cpucp->rx_base + APSS_CPUCP_RX_MBOX_EN);
  94 }
  95
  96 static int qcom_cpucp_mbox_send_data(struct mbox_chan *chan, void *data)
  97 {
  98         struct qcom_cpucp_mbox *cpucp = container_of(chan->mbox, struct qcom_cpucp_mbox, mbox);
  99         unsigned long chan_id = channel_number(chan);
 100         u32 *val = data;
 101
 102         writel(*val, cpucp->tx_base + APSS_CPUCP_TX_MBOX_CMD(chan_id) + APSS_CPUCP_MBOX_CMD_OFF);
 103
 104         return 0;
 105 }
 106
 107 static const struct mbox_chan_ops qcom_cpucp_mbox_chan_ops = {
 108         .startup = qcom_cpucp_mbox_startup,
 109         .send_data = qcom_cpucp_mbox_send_data,
 110         .shutdown = qcom_cpucp_mbox_shutdown
 111 };
 112
 113 static int qcom_cpucp_mbox_probe(struct platform_device *pdev)
 114 {
 115         struct device *dev = &pdev->dev;
 116         struct qcom_cpucp_mbox *cpucp;
 117         struct mbox_controller *mbox;
 118         int irq, ret;
 119
 120         cpucp = devm_kzalloc(dev, sizeof(*cpucp), GFP_KERNEL);
 121         if (!cpucp)
 122                 return -ENOMEM;
 123
 124         cpucp->rx_base = devm_of_iomap(dev, dev->of_node, 0, NULL);
 125         if (IS_ERR(cpucp->rx_base))
 126                 return PTR_ERR(cpucp->rx_base);
 127
 128         cpucp->tx_base = devm_of_iomap(dev, dev->of_node, 1, NULL);
 129         if (IS_ERR(cpucp->tx_base))
 130                 return PTR_ERR(cpucp->tx_base);
 131
 132         writeq(0, cpucp->rx_base + APSS_CPUCP_RX_MBOX_EN);
 133         writeq(0, cpucp->rx_base + APSS_CPUCP_RX_MBOX_CLEAR);
 134         writeq(0, cpucp->rx_base + APSS_CPUCP_RX_MBOX_MAP);
 135
 136         irq = platform_get_irq(pdev, 0);
 137         if (irq < 0)
 138                 return irq;
 139
 140         ret = devm_request_irq(dev, irq, qcom_cpucp_mbox_irq_fn,
 141                                IRQF_TRIGGER_HIGH | IRQF_NO_SUSPEND, "apss_cpucp_mbox", cpucp);
 142         if (ret < 0)
 143                 return dev_err_probe(dev, ret, "Failed to register irq: %d\n", irq);
 144
 145         writeq(APSS_CPUCP_RX_MBOX_CMD_MASK, cpucp->rx_base + APSS_CPUCP_RX_MBOX_MAP);
 146
 147         mbox = &cpucp->mbox;
 148         mbox->dev = dev;
 149         mbox->num_chans = APSS_CPUCP_IPC_CHAN_SUPPORTED;
 150         mbox->chans = cpucp->chans;
 151         mbox->ops = &qcom_cpucp_mbox_chan_ops;
 152
 153         ret = devm_mbox_controller_register(dev, mbox);
 154         if (ret)
 155                 return dev_err_probe(dev, ret, "Failed to create mailbox\n");
 156
 157         return 0;
 158 }
 159
 160 static const struct of_device_id qcom_cpucp_mbox_of_match[] = {
 161         { .compatible = "qcom,x1e80100-cpucp-mbox" },
 162         {}
 163 };
 164 MODULE_DEVICE_TABLE(of, qcom_cpucp_mbox_of_match);
 165
 166 static struct platform_driver qcom_cpucp_mbox_driver = {
 167         .probe = qcom_cpucp_mbox_probe,
 168         .driver = {
 169                 .name = "qcom_cpucp_mbox",
 170                 .of_match_table = qcom_cpucp_mbox_of_match,
 171         },
 172 };
 173
 174 static int __init qcom_cpucp_mbox_init(void)
 175 {
 176         return platform_driver_register(&qcom_cpucp_mbox_driver);
 177 }
 178 core_initcall(qcom_cpucp_mbox_init);
 179
 180 static void __exit qcom_cpucp_mbox_exit(void)
 181 {
 182         platform_driver_unregister(&qcom_cpucp_mbox_driver);
 183 }
 184 module_exit(qcom_cpucp_mbox_exit);
 185
 186 MODULE_DESCRIPTION("QTI CPUCP MBOX Driver");
 187 MODULE_LICENSE("GPL");