cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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clk-hi3660-stub.c (4596B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 * Hisilicon clock driver
      4 *
      5 * Copyright (c) 2013-2017 Hisilicon Limited.
      6 * Copyright (c) 2017 Linaro Limited.
      7 *
      8 * Author: Kai Zhao <zhaokai1@hisilicon.com>
      9 *	    Tao Wang <kevin.wangtao@hisilicon.com>
     10 *	    Leo Yan <leo.yan@linaro.org>
     11 */
     12
     13#include <linux/clk-provider.h>
     14#include <linux/device.h>
     15#include <linux/err.h>
     16#include <linux/init.h>
     17#include <linux/io.h>
     18#include <linux/mailbox_client.h>
     19#include <linux/module.h>
     20#include <linux/of.h>
     21#include <linux/platform_device.h>
     22#include <dt-bindings/clock/hi3660-clock.h>
     23
     24#define HI3660_STUB_CLOCK_DATA		(0x70)
     25#define MHZ				(1000 * 1000)
     26
     27#define DEFINE_CLK_STUB(_id, _cmd, _name)			\
     28	{							\
     29		.id = (_id),					\
     30		.cmd = (_cmd),					\
     31		.hw.init = &(struct clk_init_data) {		\
     32			.name = #_name,				\
     33			.ops = &hi3660_stub_clk_ops,		\
     34			.num_parents = 0,			\
     35			.flags = CLK_GET_RATE_NOCACHE,		\
     36		},						\
     37	},
     38
     39#define to_stub_clk(_hw) container_of(_hw, struct hi3660_stub_clk, hw)
     40
     41struct hi3660_stub_clk_chan {
     42	struct mbox_client cl;
     43	struct mbox_chan *mbox;
     44};
     45
     46struct hi3660_stub_clk {
     47	unsigned int id;
     48	struct clk_hw hw;
     49	unsigned int cmd;
     50	unsigned int msg[8];
     51	unsigned int rate;
     52};
     53
     54static void __iomem *freq_reg;
     55static struct hi3660_stub_clk_chan stub_clk_chan;
     56
     57static unsigned long hi3660_stub_clk_recalc_rate(struct clk_hw *hw,
     58						 unsigned long parent_rate)
     59{
     60	struct hi3660_stub_clk *stub_clk = to_stub_clk(hw);
     61
     62	/*
     63	 * LPM3 writes back the CPU frequency in shared SRAM so read
     64	 * back the frequency.
     65	 */
     66	stub_clk->rate = readl(freq_reg + (stub_clk->id << 2)) * MHZ;
     67	return stub_clk->rate;
     68}
     69
     70static long hi3660_stub_clk_round_rate(struct clk_hw *hw, unsigned long rate,
     71				       unsigned long *prate)
     72{
     73	/*
     74	 * LPM3 handles rate rounding so just return whatever
     75	 * rate is requested.
     76	 */
     77	return rate;
     78}
     79
     80static int hi3660_stub_clk_set_rate(struct clk_hw *hw, unsigned long rate,
     81				    unsigned long parent_rate)
     82{
     83	struct hi3660_stub_clk *stub_clk = to_stub_clk(hw);
     84
     85	stub_clk->msg[0] = stub_clk->cmd;
     86	stub_clk->msg[1] = rate / MHZ;
     87
     88	dev_dbg(stub_clk_chan.cl.dev, "set rate msg[0]=0x%x msg[1]=0x%x\n",
     89		stub_clk->msg[0], stub_clk->msg[1]);
     90
     91	mbox_send_message(stub_clk_chan.mbox, stub_clk->msg);
     92	mbox_client_txdone(stub_clk_chan.mbox, 0);
     93
     94	stub_clk->rate = rate;
     95	return 0;
     96}
     97
     98static const struct clk_ops hi3660_stub_clk_ops = {
     99	.recalc_rate    = hi3660_stub_clk_recalc_rate,
    100	.round_rate     = hi3660_stub_clk_round_rate,
    101	.set_rate       = hi3660_stub_clk_set_rate,
    102};
    103
    104static struct hi3660_stub_clk hi3660_stub_clks[HI3660_CLK_STUB_NUM] = {
    105	DEFINE_CLK_STUB(HI3660_CLK_STUB_CLUSTER0, 0x0001030A, "cpu-cluster.0")
    106	DEFINE_CLK_STUB(HI3660_CLK_STUB_CLUSTER1, 0x0002030A, "cpu-cluster.1")
    107	DEFINE_CLK_STUB(HI3660_CLK_STUB_GPU, 0x0003030A, "clk-g3d")
    108	DEFINE_CLK_STUB(HI3660_CLK_STUB_DDR, 0x00040309, "clk-ddrc")
    109};
    110
    111static struct clk_hw *hi3660_stub_clk_hw_get(struct of_phandle_args *clkspec,
    112					     void *data)
    113{
    114	unsigned int idx = clkspec->args[0];
    115
    116	if (idx >= HI3660_CLK_STUB_NUM) {
    117		pr_err("%s: invalid index %u\n", __func__, idx);
    118		return ERR_PTR(-EINVAL);
    119	}
    120
    121	return &hi3660_stub_clks[idx].hw;
    122}
    123
    124static int hi3660_stub_clk_probe(struct platform_device *pdev)
    125{
    126	struct device *dev = &pdev->dev;
    127	struct resource *res;
    128	unsigned int i;
    129	int ret;
    130
    131	/* Use mailbox client without blocking */
    132	stub_clk_chan.cl.dev = dev;
    133	stub_clk_chan.cl.tx_done = NULL;
    134	stub_clk_chan.cl.tx_block = false;
    135	stub_clk_chan.cl.knows_txdone = false;
    136
    137	/* Allocate mailbox channel */
    138	stub_clk_chan.mbox = mbox_request_channel(&stub_clk_chan.cl, 0);
    139	if (IS_ERR(stub_clk_chan.mbox))
    140		return PTR_ERR(stub_clk_chan.mbox);
    141
    142	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    143	if (!res)
    144		return -EINVAL;
    145	freq_reg = devm_ioremap(dev, res->start, resource_size(res));
    146	if (!freq_reg)
    147		return -ENOMEM;
    148
    149	freq_reg += HI3660_STUB_CLOCK_DATA;
    150
    151	for (i = 0; i < HI3660_CLK_STUB_NUM; i++) {
    152		ret = devm_clk_hw_register(&pdev->dev, &hi3660_stub_clks[i].hw);
    153		if (ret)
    154			return ret;
    155	}
    156
    157	return devm_of_clk_add_hw_provider(&pdev->dev, hi3660_stub_clk_hw_get,
    158					   hi3660_stub_clks);
    159}
    160
    161static const struct of_device_id hi3660_stub_clk_of_match[] = {
    162	{ .compatible = "hisilicon,hi3660-stub-clk", },
    163	{}
    164};
    165
    166static struct platform_driver hi3660_stub_clk_driver = {
    167	.probe	= hi3660_stub_clk_probe,
    168	.driver = {
    169		.name = "hi3660-stub-clk",
    170		.of_match_table = hi3660_stub_clk_of_match,
    171	},
    172};
    173
    174static int __init hi3660_stub_clk_init(void)
    175{
    176	return platform_driver_register(&hi3660_stub_clk_driver);
    177}
    178subsys_initcall(hi3660_stub_clk_init);