1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2016 BayLibre SAS. 4 * Author: Neil Armstrong <narmstrong@baylibre.com> 5 * Synchronised with arm_mhu.c from : 6 * Copyright (C) 2013-2015 Fujitsu Semiconductor Ltd. 7 * Copyright (C) 2015 Linaro Ltd. 8 * Author: Jassi Brar <jaswinder.singh@linaro.org> 9 */ 10 11 #include <linux/interrupt.h> 12 #include <linux/spinlock.h> 13 #include <linux/mutex.h> 14 #include <linux/delay.h> 15 #include <linux/slab.h> 16 #include <linux/err.h> 17 #include <linux/io.h> 18 #include <linux/module.h> 19 #include <linux/platform_device.h> 20 #include <linux/mailbox_controller.h> 21 22 #define INTR_SET_OFS 0x0 23 #define INTR_STAT_OFS 0x4 24 #define INTR_CLR_OFS 0x8 25 26 #define MHU_SEC_OFFSET 0x0 27 #define MHU_LP_OFFSET 0xc 28 #define MHU_HP_OFFSET 0x18 29 #define TX_REG_OFFSET 0x24 30 31 #define MHU_CHANS 3 32 33 struct platform_mhu_link { 34 int irq; 35 void __iomem *tx_reg; 36 void __iomem *rx_reg; 37 }; 38 39 struct platform_mhu { 40 void __iomem *base; 41 struct platform_mhu_link mlink[MHU_CHANS]; 42 struct mbox_chan chan[MHU_CHANS]; 43 struct mbox_controller mbox; 44 }; 45 46 static irqreturn_t platform_mhu_rx_interrupt(int irq, void *p) 47 { 48 struct mbox_chan *chan = p; 49 struct platform_mhu_link *mlink = chan->con_priv; 50 u32 val; 51 52 val = readl_relaxed(mlink->rx_reg + INTR_STAT_OFS); 53 if (!val) 54 return IRQ_NONE; 55 56 mbox_chan_received_data(chan, (void *)&val); 57 58 writel_relaxed(val, mlink->rx_reg + INTR_CLR_OFS); 59 60 return IRQ_HANDLED; 61 } 62 63 static bool platform_mhu_last_tx_done(struct mbox_chan *chan) 64 { 65 struct platform_mhu_link *mlink = chan->con_priv; 66 u32 val = readl_relaxed(mlink->tx_reg + INTR_STAT_OFS); 67 68 return (val == 0); 69 } 70 71 static int platform_mhu_send_data(struct mbox_chan *chan, void *data) 72 { 73 struct platform_mhu_link *mlink = chan->con_priv; 74 u32 *arg = data; 75 76 writel_relaxed(*arg, mlink->tx_reg + INTR_SET_OFS); 77 78 return 0; 79 } 80 81 static int platform_mhu_startup(struct mbox_chan *chan) 82 { 83 struct platform_mhu_link *mlink = chan->con_priv; 84 u32 val; 85 int ret; 86 87 val = readl_relaxed(mlink->tx_reg + INTR_STAT_OFS); 88 writel_relaxed(val, mlink->tx_reg + INTR_CLR_OFS); 89 90 ret = request_irq(mlink->irq, platform_mhu_rx_interrupt, 91 IRQF_SHARED, "platform_mhu_link", chan); 92 if (ret) { 93 dev_err(chan->mbox->dev, 94 "Unable to acquire IRQ %d\n", mlink->irq); 95 return ret; 96 } 97 98 return 0; 99 } 100 101 static void platform_mhu_shutdown(struct mbox_chan *chan) 102 { 103 struct platform_mhu_link *mlink = chan->con_priv; 104 105 free_irq(mlink->irq, chan); 106 } 107 108 static const struct mbox_chan_ops platform_mhu_ops = { 109 .send_data = platform_mhu_send_data, 110 .startup = platform_mhu_startup, 111 .shutdown = platform_mhu_shutdown, 112 .last_tx_done = platform_mhu_last_tx_done, 113 }; 114 115 static int platform_mhu_probe(struct platform_device *pdev) 116 { 117 int i, err; 118 struct platform_mhu *mhu; 119 struct device *dev = &pdev->dev; 120 int platform_mhu_reg[MHU_CHANS] = { 121 MHU_SEC_OFFSET, MHU_LP_OFFSET, MHU_HP_OFFSET 122 }; 123 124 /* Allocate memory for device */ 125 mhu = devm_kzalloc(dev, sizeof(*mhu), GFP_KERNEL); 126 if (!mhu) 127 return -ENOMEM; 128 129 mhu->base = devm_platform_ioremap_resource(pdev, 0); 130 if (IS_ERR(mhu->base)) { 131 dev_err(dev, "ioremap failed\n"); 132 return PTR_ERR(mhu->base); 133 } 134 135 for (i = 0; i < MHU_CHANS; i++) { 136 mhu->chan[i].con_priv = &mhu->mlink[i]; 137 mhu->mlink[i].irq = platform_get_irq(pdev, i); 138 if (mhu->mlink[i].irq < 0) { 139 dev_err(dev, "failed to get irq%d\n", i); 140 return mhu->mlink[i].irq; 141 } 142 mhu->mlink[i].rx_reg = mhu->base + platform_mhu_reg[i]; 143 mhu->mlink[i].tx_reg = mhu->mlink[i].rx_reg + TX_REG_OFFSET; 144 } 145 146 mhu->mbox.dev = dev; 147 mhu->mbox.chans = &mhu->chan[0]; 148 mhu->mbox.num_chans = MHU_CHANS; 149 mhu->mbox.ops = &platform_mhu_ops; 150 mhu->mbox.txdone_irq = false; 151 mhu->mbox.txdone_poll = true; 152 mhu->mbox.txpoll_period = 1; 153 154 platform_set_drvdata(pdev, mhu); 155 156 err = devm_mbox_controller_register(dev, &mhu->mbox); 157 if (err) { 158 dev_err(dev, "Failed to register mailboxes %d\n", err); 159 return err; 160 } 161 162 dev_info(dev, "Platform MHU Mailbox registered\n"); 163 return 0; 164 } 165 166 static const struct of_device_id platform_mhu_dt_ids[] = { 167 { .compatible = "amlogic,meson-gxbb-mhu", }, 168 { /* sentinel */ }, 169 }; 170 MODULE_DEVICE_TABLE(of, platform_mhu_dt_ids); 171 172 static struct platform_driver platform_mhu_driver = { 173 .probe = platform_mhu_probe, 174 .driver = { 175 .name = "platform-mhu", 176 .of_match_table = platform_mhu_dt_ids, 177 }, 178 }; 179 180 module_platform_driver(platform_mhu_driver); 181 182 MODULE_LICENSE("GPL v2"); 183 MODULE_ALIAS("platform:platform-mhu"); 184 MODULE_DESCRIPTION("Platform MHU Driver"); 185 MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>"); 186