1 /*
2  * Copyright (c) 2017, Linaro Ltd
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 and
6  * only version 2 as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  */
13 
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/io.h>
17 #include <linux/slab.h>
18 #include <linux/of.h>
19 #include <linux/of_platform.h>
20 #include <linux/platform_device.h>
21 #include <linux/regmap.h>
22 #include <linux/mailbox_controller.h>
23 
24 #define QCOM_APCS_IPC_BITS	32
25 
26 struct qcom_apcs_ipc {
27 	struct mbox_controller mbox;
28 	struct mbox_chan mbox_chans[QCOM_APCS_IPC_BITS];
29 
30 	struct regmap *regmap;
31 	unsigned long offset;
32 	struct platform_device *clk;
33 };
34 
35 static const struct regmap_config apcs_regmap_config = {
36 	.reg_bits = 32,
37 	.reg_stride = 4,
38 	.val_bits = 32,
39 	.max_register = 0x1000,
40 	.fast_io = true,
41 };
42 
43 static int qcom_apcs_ipc_send_data(struct mbox_chan *chan, void *data)
44 {
45 	struct qcom_apcs_ipc *apcs = container_of(chan->mbox,
46 						  struct qcom_apcs_ipc, mbox);
47 	unsigned long idx = (unsigned long)chan->con_priv;
48 
49 	return regmap_write(apcs->regmap, apcs->offset, BIT(idx));
50 }
51 
52 static const struct mbox_chan_ops qcom_apcs_ipc_ops = {
53 	.send_data = qcom_apcs_ipc_send_data,
54 };
55 
56 static int qcom_apcs_ipc_probe(struct platform_device *pdev)
57 {
58 	struct device_node *np = pdev->dev.of_node;
59 	struct qcom_apcs_ipc *apcs;
60 	struct regmap *regmap;
61 	struct resource *res;
62 	unsigned long offset;
63 	void __iomem *base;
64 	unsigned long i;
65 	int ret;
66 
67 	apcs = devm_kzalloc(&pdev->dev, sizeof(*apcs), GFP_KERNEL);
68 	if (!apcs)
69 		return -ENOMEM;
70 
71 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
72 	base = devm_ioremap_resource(&pdev->dev, res);
73 	if (IS_ERR(base))
74 		return PTR_ERR(base);
75 
76 	regmap = devm_regmap_init_mmio(&pdev->dev, base, &apcs_regmap_config);
77 	if (IS_ERR(regmap))
78 		return PTR_ERR(regmap);
79 
80 	offset = (unsigned long)of_device_get_match_data(&pdev->dev);
81 
82 	apcs->regmap = regmap;
83 	apcs->offset = offset;
84 
85 	/* Initialize channel identifiers */
86 	for (i = 0; i < ARRAY_SIZE(apcs->mbox_chans); i++)
87 		apcs->mbox_chans[i].con_priv = (void *)i;
88 
89 	apcs->mbox.dev = &pdev->dev;
90 	apcs->mbox.ops = &qcom_apcs_ipc_ops;
91 	apcs->mbox.chans = apcs->mbox_chans;
92 	apcs->mbox.num_chans = ARRAY_SIZE(apcs->mbox_chans);
93 
94 	ret = mbox_controller_register(&apcs->mbox);
95 	if (ret) {
96 		dev_err(&pdev->dev, "failed to register APCS IPC controller\n");
97 		return ret;
98 	}
99 
100 	if (of_device_is_compatible(np, "qcom,msm8916-apcs-kpss-global")) {
101 		apcs->clk = platform_device_register_data(&pdev->dev,
102 							  "qcom-apcs-msm8916-clk",
103 							  -1, NULL, 0);
104 		if (IS_ERR(apcs->clk))
105 			dev_err(&pdev->dev, "failed to register APCS clk\n");
106 	}
107 
108 	platform_set_drvdata(pdev, apcs);
109 
110 	return 0;
111 }
112 
113 static int qcom_apcs_ipc_remove(struct platform_device *pdev)
114 {
115 	struct qcom_apcs_ipc *apcs = platform_get_drvdata(pdev);
116 	struct platform_device *clk = apcs->clk;
117 
118 	mbox_controller_unregister(&apcs->mbox);
119 	platform_device_unregister(clk);
120 
121 	return 0;
122 }
123 
124 /* .data is the offset of the ipc register within the global block */
125 static const struct of_device_id qcom_apcs_ipc_of_match[] = {
126 	{ .compatible = "qcom,msm8916-apcs-kpss-global", .data = (void *)8 },
127 	{ .compatible = "qcom,msm8996-apcs-hmss-global", .data = (void *)16 },
128 	{}
129 };
130 MODULE_DEVICE_TABLE(of, qcom_apcs_ipc_of_match);
131 
132 static struct platform_driver qcom_apcs_ipc_driver = {
133 	.probe = qcom_apcs_ipc_probe,
134 	.remove = qcom_apcs_ipc_remove,
135 	.driver = {
136 		.name = "qcom_apcs_ipc",
137 		.of_match_table = qcom_apcs_ipc_of_match,
138 	},
139 };
140 
141 static int __init qcom_apcs_ipc_init(void)
142 {
143 	return platform_driver_register(&qcom_apcs_ipc_driver);
144 }
145 postcore_initcall(qcom_apcs_ipc_init);
146 
147 static void __exit qcom_apcs_ipc_exit(void)
148 {
149 	platform_driver_unregister(&qcom_apcs_ipc_driver);
150 }
151 module_exit(qcom_apcs_ipc_exit);
152 
153 MODULE_LICENSE("GPL v2");
154 MODULE_DESCRIPTION("Qualcomm APCS IPC driver");
155