1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * ARM PL353 SMC driver
  4 *
  5 * Copyright (C) 2012 - 2018 Xilinx, Inc
  6 * Author: Punnaiah Choudary Kalluri <punnaiah@xilinx.com>
  7 * Author: Naga Sureshkumar Relli <nagasure@xilinx.com>
  8 */
  9
 10#include <linux/clk.h>
 11#include <linux/kernel.h>
 12#include <linux/module.h>
 13#include <linux/of_platform.h>
 14#include <linux/platform_device.h>
 15#include <linux/amba/bus.h>
 16
 17/**
 18 * struct pl353_smc_data - Private smc driver structure
 19 * @memclk:		Pointer to the peripheral clock
 20 * @aclk:		Pointer to the AXI peripheral clock
 21 */
 22struct pl353_smc_data {
 23	struct clk		*memclk;
 24	struct clk		*aclk;
 25};
 26
 27static int __maybe_unused pl353_smc_suspend(struct device *dev)
 28{
 29	struct pl353_smc_data *pl353_smc = dev_get_drvdata(dev);
 30
 31	clk_disable(pl353_smc->memclk);
 32	clk_disable(pl353_smc->aclk);
 33
 34	return 0;
 35}
 36
 37static int __maybe_unused pl353_smc_resume(struct device *dev)
 38{
 39	struct pl353_smc_data *pl353_smc = dev_get_drvdata(dev);
 40	int ret;
 41
 42	ret = clk_enable(pl353_smc->aclk);
 43	if (ret) {
 44		dev_err(dev, "Cannot enable axi domain clock.\n");
 45		return ret;
 46	}
 47
 48	ret = clk_enable(pl353_smc->memclk);
 49	if (ret) {
 50		dev_err(dev, "Cannot enable memory clock.\n");
 51		clk_disable(pl353_smc->aclk);
 52		return ret;
 53	}
 54
 55	return ret;
 56}
 57
 58static SIMPLE_DEV_PM_OPS(pl353_smc_dev_pm_ops, pl353_smc_suspend,
 59			 pl353_smc_resume);
 60
 61static const struct of_device_id pl353_smc_supported_children[] = {
 62	{
 63		.compatible = "cfi-flash"
 64	},
 65	{
 66		.compatible = "arm,pl353-nand-r2p1",
 67	},
 68	{}
 69};
 70
 71static int pl353_smc_probe(struct amba_device *adev, const struct amba_id *id)
 72{
 73	struct device_node *of_node = adev->dev.of_node;
 74	const struct of_device_id *match = NULL;
 75	struct pl353_smc_data *pl353_smc;
 76	struct device_node *child;
 77	int err;
 78
 79	pl353_smc = devm_kzalloc(&adev->dev, sizeof(*pl353_smc), GFP_KERNEL);
 80	if (!pl353_smc)
 81		return -ENOMEM;
 82
 83	pl353_smc->aclk = devm_clk_get(&adev->dev, "apb_pclk");
 84	if (IS_ERR(pl353_smc->aclk)) {
 85		dev_err(&adev->dev, "aclk clock not found.\n");
 86		return PTR_ERR(pl353_smc->aclk);
 87	}
 88
 89	pl353_smc->memclk = devm_clk_get(&adev->dev, "memclk");
 90	if (IS_ERR(pl353_smc->memclk)) {
 91		dev_err(&adev->dev, "memclk clock not found.\n");
 92		return PTR_ERR(pl353_smc->memclk);
 93	}
 94
 95	err = clk_prepare_enable(pl353_smc->aclk);
 96	if (err) {
 97		dev_err(&adev->dev, "Unable to enable AXI clock.\n");
 98		return err;
 99	}
100
101	err = clk_prepare_enable(pl353_smc->memclk);
102	if (err) {
103		dev_err(&adev->dev, "Unable to enable memory clock.\n");
104		goto disable_axi_clk;
105	}
106
107	amba_set_drvdata(adev, pl353_smc);
108
109	/* Find compatible children. Only a single child is supported */
110	for_each_available_child_of_node(of_node, child) {
111		match = of_match_node(pl353_smc_supported_children, child);
112		if (!match) {
113			dev_warn(&adev->dev, "unsupported child node\n");
114			continue;
115		}
116		break;
117	}
118	if (!match) {
119		err = -ENODEV;
120		dev_err(&adev->dev, "no matching children\n");
121		goto disable_mem_clk;
122	}
123
124	of_platform_device_create(child, NULL, &adev->dev);
125	of_node_put(child);
126
127	return 0;
128
129disable_mem_clk:
130	clk_disable_unprepare(pl353_smc->memclk);
131disable_axi_clk:
132	clk_disable_unprepare(pl353_smc->aclk);
133
134	return err;
135}
136
137static void pl353_smc_remove(struct amba_device *adev)
138{
139	struct pl353_smc_data *pl353_smc = amba_get_drvdata(adev);
140
141	clk_disable_unprepare(pl353_smc->memclk);
142	clk_disable_unprepare(pl353_smc->aclk);
143}
144
145static const struct amba_id pl353_ids[] = {
146	{
147		.id = 0x00041353,
148		.mask = 0x000fffff,
149	},
150	{ 0, 0 },
151};
152MODULE_DEVICE_TABLE(amba, pl353_ids);
153
154static struct amba_driver pl353_smc_driver = {
155	.drv = {
156		.owner = THIS_MODULE,
157		.name = "pl353-smc",
158		.pm = &pl353_smc_dev_pm_ops,
159	},
160	.id_table = pl353_ids,
161	.probe = pl353_smc_probe,
162	.remove = pl353_smc_remove,
163};
164
165module_amba_driver(pl353_smc_driver);
166
167MODULE_AUTHOR("Xilinx, Inc.");
168MODULE_DESCRIPTION("ARM PL353 SMC Driver");
169MODULE_LICENSE("GPL");