Per Åstrand | be87baf | 2020-10-07 13:47:24 +0200 | [diff] [blame^] | 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | /* |
| 3 | * Message Handling Unit version 2 controller driver |
| 4 | * Copyright (C) 2019 ARM Ltd. |
| 5 | * |
| 6 | * Based on drivers/mailbox/arm_mhu.c |
| 7 | * |
| 8 | */ |
| 9 | |
| 10 | #include <linux/interrupt.h> |
| 11 | #include <linux/mutex.h> |
| 12 | #include <linux/slab.h> |
| 13 | #include <linux/err.h> |
| 14 | #include <linux/io.h> |
| 15 | #include <linux/module.h> |
| 16 | #include <linux/amba/bus.h> |
| 17 | #include <linux/mailbox_controller.h> |
| 18 | #include <linux/of_device.h> |
| 19 | #include <linux/of_address.h> |
| 20 | |
| 21 | #define MHU_V2_REG_STAT_OFS 0x0 |
| 22 | #define MHU_V2_REG_CLR_OFS 0x8 |
| 23 | #define MHU_V2_REG_SET_OFS 0xC |
| 24 | #define MHU_V2_REG_MSG_NO_CAP_OFS 0xF80 |
| 25 | #define MHU_V2_REG_ACC_REQ_OFS 0xF88 |
| 26 | #define MHU_V2_REG_ACC_RDY_OFS 0xF8C |
| 27 | #define MHU_V2_INT_EN_OFS 0xF98 |
| 28 | #define MHU_V2_AIDR_OFS 0xFCC |
| 29 | |
| 30 | #define MHU_V2_CHCOMB BIT(2) |
| 31 | #define MHU_V2_AIDR_MINOR(_reg) ((_reg) & 0xF) |
| 32 | |
| 33 | #define MHU_V2_EACH_CHANNEL_SIZE 0x20 |
| 34 | |
| 35 | #define mbox_to_arm_mhuv2(c) container_of(c, struct arm_mhuv2, mbox) |
| 36 | |
| 37 | struct mhuv2_link { |
| 38 | unsigned int irq; |
| 39 | void __iomem *tx_reg; |
| 40 | void __iomem *rx_reg; |
| 41 | }; |
| 42 | |
| 43 | struct arm_mhuv2 { |
| 44 | void __iomem *base; |
| 45 | struct mhuv2_link *mlink; |
| 46 | struct mbox_chan *chan; |
| 47 | struct mbox_controller mbox; |
| 48 | }; |
| 49 | |
| 50 | static irqreturn_t mhuv2_rx_interrupt(int irq, void *p) |
| 51 | { |
| 52 | struct mbox_chan *chan = p; |
| 53 | struct mhuv2_link *mlink = chan->con_priv; |
| 54 | u32 val; |
| 55 | |
| 56 | val = readl_relaxed(mlink->rx_reg + MHU_V2_REG_STAT_OFS); |
| 57 | if (!val) |
| 58 | return IRQ_NONE; |
| 59 | |
| 60 | mbox_chan_received_data(chan, (void *)&val); |
| 61 | |
| 62 | writel_relaxed(val, mlink->rx_reg + MHU_V2_REG_CLR_OFS); |
| 63 | |
| 64 | return IRQ_HANDLED; |
| 65 | } |
| 66 | |
| 67 | static bool mhuv2_last_tx_done(struct mbox_chan *chan) |
| 68 | { |
| 69 | struct mhuv2_link *mlink = chan->con_priv; |
| 70 | u32 val = readl_relaxed(mlink->tx_reg + MHU_V2_REG_STAT_OFS); |
| 71 | |
| 72 | return (val == 0); |
| 73 | } |
| 74 | |
| 75 | static int mhuv2_send_data(struct mbox_chan *chan, void *data) |
| 76 | { |
| 77 | struct mhuv2_link *mlink = chan->con_priv; |
| 78 | u32 *arg = data; |
| 79 | |
| 80 | writel_relaxed(*arg, mlink->tx_reg + MHU_V2_REG_SET_OFS); |
| 81 | |
| 82 | return 0; |
| 83 | } |
| 84 | |
| 85 | static int mhuv2_startup(struct mbox_chan *chan) |
| 86 | { |
| 87 | struct mhuv2_link *mlink = chan->con_priv; |
| 88 | u32 val; |
| 89 | int ret; |
| 90 | struct arm_mhuv2 *mhuv2 = mbox_to_arm_mhuv2(chan->mbox); |
| 91 | |
| 92 | writel_relaxed(0x1, mhuv2->base + MHU_V2_REG_ACC_REQ_OFS); |
| 93 | |
| 94 | val = readl_relaxed(mlink->tx_reg + MHU_V2_REG_STAT_OFS); |
| 95 | writel_relaxed(val, mlink->tx_reg + MHU_V2_REG_CLR_OFS); |
| 96 | |
| 97 | ret = request_irq(mlink->irq, mhuv2_rx_interrupt, |
| 98 | IRQF_SHARED, "mhuv2_link", chan); |
| 99 | if (ret) { |
| 100 | dev_err(chan->mbox->dev, |
| 101 | "unable to acquire IRQ %d\n", mlink->irq); |
| 102 | return ret; |
| 103 | } |
| 104 | |
| 105 | return 0; |
| 106 | } |
| 107 | |
| 108 | static void mhuv2_shutdown(struct mbox_chan *chan) |
| 109 | { |
| 110 | struct mhuv2_link *mlink = chan->con_priv; |
| 111 | struct arm_mhuv2 *mhuv2 = mbox_to_arm_mhuv2(chan->mbox); |
| 112 | |
| 113 | writel_relaxed(0x0, mhuv2->base + MHU_V2_REG_ACC_REQ_OFS); |
| 114 | |
| 115 | free_irq(mlink->irq, chan); |
| 116 | } |
| 117 | |
| 118 | static const struct mbox_chan_ops mhuv2_ops = { |
| 119 | .send_data = mhuv2_send_data, |
| 120 | .startup = mhuv2_startup, |
| 121 | .shutdown = mhuv2_shutdown, |
| 122 | .last_tx_done = mhuv2_last_tx_done, |
| 123 | }; |
| 124 | |
| 125 | void mhuv2_check_enable_cmbint(struct mhuv2_link *link) |
| 126 | { |
| 127 | const u32 aidr = readl_relaxed(link->rx_reg + MHU_V2_AIDR_OFS); |
| 128 | |
| 129 | if (MHU_V2_AIDR_MINOR(aidr) == 1) { |
| 130 | // Enable combined receiver interrupt for MHUv2.1 |
| 131 | writel_relaxed(MHU_V2_CHCOMB, link->rx_reg + MHU_V2_INT_EN_OFS); |
| 132 | } |
| 133 | } |
| 134 | |
| 135 | static int mhuv2_probe(struct amba_device *adev, const struct amba_id *id) |
| 136 | { |
| 137 | int i, err; |
| 138 | struct arm_mhuv2 *mhuv2; |
| 139 | struct device *dev = &adev->dev; |
| 140 | void __iomem *rx_base, *tx_base; |
| 141 | const struct device_node *np = dev->of_node; |
| 142 | unsigned int pchans; |
| 143 | struct mhuv2_link *mlink; |
| 144 | struct mbox_chan *chan; |
| 145 | |
| 146 | |
| 147 | /* Allocate memory for device */ |
| 148 | mhuv2 = devm_kzalloc(dev, sizeof(*mhuv2), GFP_KERNEL); |
| 149 | if (!mhuv2) |
| 150 | return -ENOMEM; |
| 151 | |
| 152 | tx_base = of_iomap((struct device_node *)np, 0); |
| 153 | if (!tx_base) { |
| 154 | dev_err(dev, "failed to map tx registers\n"); |
| 155 | iounmap(rx_base); |
| 156 | return -ENOMEM; |
| 157 | } |
| 158 | |
| 159 | rx_base = of_iomap((struct device_node *)np, 1); |
| 160 | if (!rx_base) { |
| 161 | dev_err(dev, "failed to map rx registers\n"); |
| 162 | return -ENOMEM; |
| 163 | } |
| 164 | |
| 165 | pchans = readl_relaxed(tx_base + MHU_V2_REG_MSG_NO_CAP_OFS); |
| 166 | if (pchans == 0 || pchans % 2) { |
| 167 | dev_err(dev, "invalid number of channels %d\n", pchans); |
| 168 | iounmap(rx_base); |
| 169 | iounmap(tx_base); |
| 170 | return -EINVAL; |
| 171 | } |
| 172 | |
| 173 | mhuv2->mlink = devm_kcalloc(dev, pchans, sizeof(*mlink), GFP_KERNEL); |
| 174 | if (!mhuv2->mlink) { |
| 175 | iounmap(rx_base); |
| 176 | iounmap(tx_base); |
| 177 | return -ENOMEM; |
| 178 | } |
| 179 | |
| 180 | mhuv2->chan = devm_kcalloc(dev, pchans, sizeof(*chan), GFP_KERNEL); |
| 181 | if (!mhuv2->chan) { |
| 182 | iounmap(rx_base); |
| 183 | iounmap(tx_base); |
| 184 | kfree(mhuv2->mlink); |
| 185 | return -ENOMEM; |
| 186 | } |
| 187 | |
| 188 | for (i = 0; i < pchans; i++) { |
| 189 | mlink = mhuv2->mlink + i; |
| 190 | chan = mhuv2->chan + i; |
| 191 | chan->con_priv = mlink; |
| 192 | mlink->rx_reg = rx_base + (i * MHU_V2_EACH_CHANNEL_SIZE); |
| 193 | mlink->tx_reg = tx_base + (i * MHU_V2_EACH_CHANNEL_SIZE); |
| 194 | } |
| 195 | |
| 196 | mhuv2->mlink->irq = adev->irq[0]; |
| 197 | mhuv2_check_enable_cmbint(mhuv2->mlink); |
| 198 | |
| 199 | mhuv2->base = tx_base; |
| 200 | mhuv2->mbox.dev = dev; |
| 201 | mhuv2->mbox.chans = mhuv2->chan; |
| 202 | mhuv2->mbox.num_chans = pchans; |
| 203 | mhuv2->mbox.ops = &mhuv2_ops; |
| 204 | mhuv2->mbox.txdone_irq = false; |
| 205 | mhuv2->mbox.txdone_poll = true; |
| 206 | mhuv2->mbox.txpoll_period = 1; |
| 207 | |
| 208 | amba_set_drvdata(adev, mhuv2); |
| 209 | |
| 210 | err = mbox_controller_register(&mhuv2->mbox); |
| 211 | if (err) { |
| 212 | dev_err(dev, "failed to register mailboxes %d\n", err); |
| 213 | iounmap(rx_base); |
| 214 | iounmap(tx_base); |
| 215 | kfree(mhuv2->mlink); |
| 216 | kfree(mhuv2->chan); |
| 217 | return err; |
| 218 | } |
| 219 | |
| 220 | dev_info(dev, "ARM MHUv2 Mailbox driver registered\n"); |
| 221 | return 0; |
| 222 | } |
| 223 | |
| 224 | static int mhuv2_remove(struct amba_device *adev) |
| 225 | { |
| 226 | struct arm_mhuv2 *mhuv2 = amba_get_drvdata(adev); |
| 227 | |
| 228 | mbox_controller_unregister(&mhuv2->mbox); |
| 229 | |
| 230 | return 0; |
| 231 | } |
| 232 | |
| 233 | static struct amba_id mhuv2_ids[] = { |
| 234 | { |
| 235 | .id = 0x4b0d1, |
| 236 | .mask = 0xfffff, |
| 237 | }, |
| 238 | { |
| 239 | .id = 0xbb0d1, |
| 240 | .mask = 0xfffff, |
| 241 | }, |
| 242 | { |
| 243 | .id = 0xbb076, |
| 244 | .mask = 0xfffff, |
| 245 | }, |
| 246 | { 0, 0 }, |
| 247 | }; |
| 248 | MODULE_DEVICE_TABLE(amba, mhuv2_ids); |
| 249 | |
| 250 | static struct amba_driver arm_mhuv2_driver = { |
| 251 | .drv = { |
| 252 | .name = "mhuv2", |
| 253 | }, |
| 254 | .id_table = mhuv2_ids, |
| 255 | .probe = mhuv2_probe, |
| 256 | .remove = mhuv2_remove, |
| 257 | }; |
| 258 | module_amba_driver(arm_mhuv2_driver); |
| 259 | |
| 260 | MODULE_LICENSE("GPL v2"); |
| 261 | MODULE_DESCRIPTION("ARM MHUv2 Driver"); |
| 262 | MODULE_AUTHOR("Samarth Parikh <samarthp@ymail.com>"); |