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.h>
 14#include <linux/of_platform.h>
 15#include <linux/platform_device.h>
 16#include <linux/amba/bus.h>
 17
 18/**
 19 * struct pl353_smc_data - Private smc driver structure
 20 * @memclk:		Pointer to the peripheral clock
 21 * @aclk:		Pointer to the AXI peripheral clock
 22 */
 23struct pl353_smc_data {
 24	struct clk		*memclk;
 25	struct clk		*aclk;
 26};
 27
 28static int __maybe_unused pl353_smc_suspend(struct device *dev)
 29{
 30	struct pl353_smc_data *pl353_smc = dev_get_drvdata(dev);
 31
 32	clk_disable(pl353_smc->memclk);
 33	clk_disable(pl353_smc->aclk);
 34
 35	return 0;
 36}
 37
 38static int __maybe_unused pl353_smc_resume(struct device *dev)
 39{
 40	struct pl353_smc_data *pl353_smc = dev_get_drvdata(dev);
 41	int ret;
 42
 43	ret = clk_enable(pl353_smc->aclk);
 44	if (ret) {
 45		dev_err(dev, "Cannot enable axi domain clock.\n");
 46		return ret;
 47	}
 48
 49	ret = clk_enable(pl353_smc->memclk);
 50	if (ret) {
 51		dev_err(dev, "Cannot enable memory clock.\n");
 52		clk_disable(pl353_smc->aclk);
 53		return ret;
 54	}
 55
 56	return ret;
 57}
 58
 59static SIMPLE_DEV_PM_OPS(pl353_smc_dev_pm_ops, pl353_smc_suspend,
 60			 pl353_smc_resume);
 61
 62static const struct of_device_id pl353_smc_supported_children[] = {
 63	{
 64		.compatible = "cfi-flash"
 65	},
 66	{
 67		.compatible = "arm,pl353-nand-r2p1",
 68	},
 69	{}
 70};
 71
 72static int pl353_smc_probe(struct amba_device *adev, const struct amba_id *id)
 73{
 74	struct device_node *of_node = adev->dev.of_node;
 75	const struct of_device_id *match = NULL;
 76	struct pl353_smc_data *pl353_smc;
 77	struct device_node *child;
 78	int err;
 79
 80	pl353_smc = devm_kzalloc(&adev->dev, sizeof(*pl353_smc), GFP_KERNEL);
 81	if (!pl353_smc)
 82		return -ENOMEM;
 83
 84	pl353_smc->aclk = devm_clk_get(&adev->dev, "apb_pclk");
 85	if (IS_ERR(pl353_smc->aclk)) {
 86		dev_err(&adev->dev, "aclk clock not found.\n");
 87		return PTR_ERR(pl353_smc->aclk);
 88	}
 89
 90	pl353_smc->memclk = devm_clk_get(&adev->dev, "memclk");
 91	if (IS_ERR(pl353_smc->memclk)) {
 92		dev_err(&adev->dev, "memclk clock not found.\n");
 93		return PTR_ERR(pl353_smc->memclk);
 94	}
 95
 96	err = clk_prepare_enable(pl353_smc->aclk);
 97	if (err) {
 98		dev_err(&adev->dev, "Unable to enable AXI clock.\n");
 99		return err;
100	}
101
102	err = clk_prepare_enable(pl353_smc->memclk);
103	if (err) {
104		dev_err(&adev->dev, "Unable to enable memory clock.\n");
105		goto disable_axi_clk;
106	}
107
108	amba_set_drvdata(adev, pl353_smc);
109
110	/* Find compatible children. Only a single child is supported */
111	for_each_available_child_of_node(of_node, child) {
112		match = of_match_node(pl353_smc_supported_children, child);
113		if (!match) {
114			dev_warn(&adev->dev, "unsupported child node\n");
115			continue;
116		}
117		break;
118	}
119	if (!match) {
120		err = -ENODEV;
121		dev_err(&adev->dev, "no matching children\n");
122		goto disable_mem_clk;
123	}
124
125	of_platform_device_create(child, NULL, &adev->dev);
126	of_node_put(child);
127
128	return 0;
129
130disable_mem_clk:
131	clk_disable_unprepare(pl353_smc->memclk);
132disable_axi_clk:
133	clk_disable_unprepare(pl353_smc->aclk);
134
135	return err;
136}
137
138static void pl353_smc_remove(struct amba_device *adev)
139{
140	struct pl353_smc_data *pl353_smc = amba_get_drvdata(adev);
141
142	clk_disable_unprepare(pl353_smc->memclk);
143	clk_disable_unprepare(pl353_smc->aclk);
144}
145
146static const struct amba_id pl353_ids[] = {
147	{
148		.id = 0x00041353,
149		.mask = 0x000fffff,
150	},
151	{ 0, 0 },
152};
153MODULE_DEVICE_TABLE(amba, pl353_ids);
154
155static struct amba_driver pl353_smc_driver = {
156	.drv = {
157		.owner = THIS_MODULE,
158		.name = "pl353-smc",
159		.pm = &pl353_smc_dev_pm_ops,
160	},
161	.id_table = pl353_ids,
162	.probe = pl353_smc_probe,
163	.remove = pl353_smc_remove,
164};
165
166module_amba_driver(pl353_smc_driver);
167
168MODULE_AUTHOR("Xilinx, Inc.");
169MODULE_DESCRIPTION("ARM PL353 SMC Driver");
170MODULE_LICENSE("GPL");