1 // SPDX-License-Identifier: GPL-2.0
3 * Microchip PolarFire SoC (MPFS) system controller/mailbox controller driver
5 * Copyright (c) 2020 Microchip Corporation. All rights reserved.
7 * Author: Conor Dooley <conor.dooley@microchip.com>
12 #include <linux/err.h>
13 #include <linux/init.h>
14 #include <linux/module.h>
15 #include <linux/kernel.h>
16 #include <linux/interrupt.h>
17 #include <linux/platform_device.h>
18 #include <linux/mailbox_controller.h>
19 #include <soc/microchip/mpfs.h>
21 #define SERVICES_CR_OFFSET 0x50u
22 #define SERVICES_SR_OFFSET 0x54u
23 #define MAILBOX_REG_OFFSET 0x800u
24 #define MSS_SYS_MAILBOX_DATA_OFFSET 0u
25 #define SCB_MASK_WIDTH 16u
27 /* SCBCTRL service control register */
29 #define SCB_CTRL_REQ (0)
30 #define SCB_CTRL_REQ_MASK BIT(SCB_CTRL_REQ)
32 #define SCB_CTRL_BUSY (1)
33 #define SCB_CTRL_BUSY_MASK BIT(SCB_CTRL_BUSY)
35 #define SCB_CTRL_ABORT (2)
36 #define SCB_CTRL_ABORT_MASK BIT(SCB_CTRL_ABORT)
38 #define SCB_CTRL_NOTIFY (3)
39 #define SCB_CTRL_NOTIFY_MASK BIT(SCB_CTRL_NOTIFY)
41 #define SCB_CTRL_POS (16)
42 #define SCB_CTRL_MASK GENMASK_ULL(SCB_CTRL_POS + SCB_MASK_WIDTH, SCB_CTRL_POS)
44 /* SCBCTRL service status register */
46 #define SCB_STATUS_REQ (0)
47 #define SCB_STATUS_REQ_MASK BIT(SCB_STATUS_REQ)
49 #define SCB_STATUS_BUSY (1)
50 #define SCB_STATUS_BUSY_MASK BIT(SCB_STATUS_BUSY)
52 #define SCB_STATUS_ABORT (2)
53 #define SCB_STATUS_ABORT_MASK BIT(SCB_STATUS_ABORT)
55 #define SCB_STATUS_NOTIFY (3)
56 #define SCB_STATUS_NOTIFY_MASK BIT(SCB_STATUS_NOTIFY)
58 #define SCB_STATUS_POS (16)
59 #define SCB_STATUS_MASK GENMASK_ULL(SCB_STATUS_POS + SCB_MASK_WIDTH, SCB_STATUS_POS)
62 struct mbox_controller controller;
65 void __iomem *ctrl_base;
66 void __iomem *mbox_base;
67 void __iomem *int_reg;
68 struct mbox_chan chans[1];
69 struct mpfs_mss_response *response;
73 static bool mpfs_mbox_busy(struct mpfs_mbox *mbox)
77 status = readl_relaxed(mbox->ctrl_base + SERVICES_SR_OFFSET);
79 return status & SCB_STATUS_BUSY_MASK;
82 static int mpfs_mbox_send_data(struct mbox_chan *chan, void *data)
84 struct mpfs_mbox *mbox = (struct mpfs_mbox *)chan->con_priv;
85 struct mpfs_mss_msg *msg = data;
90 mbox->response = msg->response;
91 mbox->resp_offset = msg->resp_offset;
93 if (mpfs_mbox_busy(mbox))
96 if (msg->cmd_data_size) {
98 u8 extra_bits = msg->cmd_data_size & 3;
99 u32 *word_buf = (u32 *)msg->cmd_data;
101 for (index = 0; index < (msg->cmd_data_size / 4); index++)
102 writel_relaxed(word_buf[index],
103 mbox->mbox_base + msg->mbox_offset + index * 0x4);
106 u8 byte_off = ALIGN_DOWN(msg->cmd_data_size, 4);
107 u8 *byte_buf = msg->cmd_data + byte_off;
109 val = readl_relaxed(mbox->mbox_base + msg->mbox_offset + index * 0x4);
111 for (i = 0u; i < extra_bits; i++) {
112 val &= ~(0xffu << (i * 8u));
113 val |= (byte_buf[i] << (i * 8u));
116 writel_relaxed(val, mbox->mbox_base + msg->mbox_offset + index * 0x4);
120 opt_sel = ((msg->mbox_offset << 7u) | (msg->cmd_opcode & 0x7fu));
121 tx_trigger = (opt_sel << SCB_CTRL_POS) & SCB_CTRL_MASK;
122 tx_trigger |= SCB_CTRL_REQ_MASK | SCB_STATUS_NOTIFY_MASK;
123 writel_relaxed(tx_trigger, mbox->ctrl_base + SERVICES_CR_OFFSET);
128 static void mpfs_mbox_rx_data(struct mbox_chan *chan)
130 struct mpfs_mbox *mbox = (struct mpfs_mbox *)chan->con_priv;
131 struct mpfs_mss_response *response = mbox->response;
132 u16 num_words = ALIGN((response->resp_size), (4)) / 4U;
135 if (!response->resp_msg) {
136 dev_err(mbox->dev, "failed to assign memory for response %d\n", -ENOMEM);
140 if (!mpfs_mbox_busy(mbox)) {
141 for (i = 0; i < num_words; i++) {
142 response->resp_msg[i] =
143 readl_relaxed(mbox->mbox_base
144 + mbox->resp_offset + i * 0x4);
148 mbox_chan_received_data(chan, response);
151 static irqreturn_t mpfs_mbox_inbox_isr(int irq, void *data)
153 struct mbox_chan *chan = data;
154 struct mpfs_mbox *mbox = (struct mpfs_mbox *)chan->con_priv;
156 writel_relaxed(0, mbox->int_reg);
158 mpfs_mbox_rx_data(chan);
160 mbox_chan_txdone(chan, 0);
164 static int mpfs_mbox_startup(struct mbox_chan *chan)
166 struct mpfs_mbox *mbox = (struct mpfs_mbox *)chan->con_priv;
172 ret = devm_request_irq(mbox->dev, mbox->irq, mpfs_mbox_inbox_isr, 0, "mpfs-mailbox", chan);
174 dev_err(mbox->dev, "failed to register mailbox interrupt:%d\n", ret);
179 static void mpfs_mbox_shutdown(struct mbox_chan *chan)
181 struct mpfs_mbox *mbox = (struct mpfs_mbox *)chan->con_priv;
183 devm_free_irq(mbox->dev, mbox->irq, chan);
186 static const struct mbox_chan_ops mpfs_mbox_ops = {
187 .send_data = mpfs_mbox_send_data,
188 .startup = mpfs_mbox_startup,
189 .shutdown = mpfs_mbox_shutdown,
192 static int mpfs_mbox_probe(struct platform_device *pdev)
194 struct mpfs_mbox *mbox;
195 struct resource *regs;
198 mbox = devm_kzalloc(&pdev->dev, sizeof(*mbox), GFP_KERNEL);
202 mbox->ctrl_base = devm_platform_get_and_ioremap_resource(pdev, 0, ®s);
203 if (IS_ERR(mbox->ctrl_base))
204 return PTR_ERR(mbox->ctrl_base);
206 mbox->int_reg = devm_platform_get_and_ioremap_resource(pdev, 1, ®s);
207 if (IS_ERR(mbox->int_reg))
208 return PTR_ERR(mbox->int_reg);
210 mbox->mbox_base = devm_platform_get_and_ioremap_resource(pdev, 2, ®s);
211 if (IS_ERR(mbox->mbox_base)) // account for the old dt-binding w/ 2 regs
212 mbox->mbox_base = mbox->ctrl_base + MAILBOX_REG_OFFSET;
214 mbox->irq = platform_get_irq(pdev, 0);
218 mbox->dev = &pdev->dev;
220 mbox->chans[0].con_priv = mbox;
221 mbox->controller.dev = mbox->dev;
222 mbox->controller.num_chans = 1;
223 mbox->controller.chans = mbox->chans;
224 mbox->controller.ops = &mpfs_mbox_ops;
225 mbox->controller.txdone_irq = true;
227 ret = devm_mbox_controller_register(&pdev->dev, &mbox->controller);
229 dev_err(&pdev->dev, "Registering MPFS mailbox controller failed\n");
232 dev_info(&pdev->dev, "Registered MPFS mailbox controller driver\n");
237 static const struct of_device_id mpfs_mbox_of_match[] = {
238 {.compatible = "microchip,mpfs-mailbox", },
241 MODULE_DEVICE_TABLE(of, mpfs_mbox_of_match);
243 static struct platform_driver mpfs_mbox_driver = {
245 .name = "mpfs-mailbox",
246 .of_match_table = mpfs_mbox_of_match,
248 .probe = mpfs_mbox_probe,
250 module_platform_driver(mpfs_mbox_driver);
252 MODULE_LICENSE("GPL v2");
253 MODULE_AUTHOR("Conor Dooley <conor.dooley@microchip.com>");
254 MODULE_DESCRIPTION("MPFS mailbox controller driver");