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/*
* Hisilicon clock driver
*
* Copyright (c) 2013-2017 Hisilicon Limited.
* Copyright (c) 2017 Linaro Limited.
*
* Author: Kai Zhao <zhaokai1@hisilicon.com>
* Tao Wang <kevin.wangtao@hisilicon.com>
* Leo Yan <leo.yan@linaro.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#include <linux/clk-provider.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/mailbox_client.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <dt-bindings/clock/hi3660-clock.h>
#define HI3660_STUB_CLOCK_DATA (0x70)
#define MHZ (1000 * 1000)
#define DEFINE_CLK_STUB(_id, _cmd, _name) \
{ \
.id = (_id), \
.cmd = (_cmd), \
.hw.init = &(struct clk_init_data) { \
.name = #_name, \
.ops = &hi3660_stub_clk_ops, \
.num_parents = 0, \
.flags = CLK_GET_RATE_NOCACHE, \
}, \
},
#define to_stub_clk(_hw) container_of(_hw, struct hi3660_stub_clk, hw)
struct hi3660_stub_clk_chan {
struct mbox_client cl;
struct mbox_chan *mbox;
};
struct hi3660_stub_clk {
unsigned int id;
struct clk_hw hw;
unsigned int cmd;
unsigned int msg[8];
unsigned int rate;
};
static void __iomem *freq_reg;
static struct hi3660_stub_clk_chan stub_clk_chan;
static unsigned long hi3660_stub_clk_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct hi3660_stub_clk *stub_clk = to_stub_clk(hw);
/*
* LPM3 writes back the CPU frequency in shared SRAM so read
* back the frequency.
*/
stub_clk->rate = readl(freq_reg + (stub_clk->id << 2)) * MHZ;
return stub_clk->rate;
}
static long hi3660_stub_clk_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *prate)
{
/*
* LPM3 handles rate rounding so just return whatever
* rate is requested.
*/
return rate;
}
static int hi3660_stub_clk_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct hi3660_stub_clk *stub_clk = to_stub_clk(hw);
stub_clk->msg[0] = stub_clk->cmd;
stub_clk->msg[1] = rate / MHZ;
dev_dbg(stub_clk_chan.cl.dev, "set rate msg[0]=0x%x msg[1]=0x%x\n",
stub_clk->msg[0], stub_clk->msg[1]);
mbox_send_message(stub_clk_chan.mbox, stub_clk->msg);
mbox_client_txdone(stub_clk_chan.mbox, 0);
stub_clk->rate = rate;
return 0;
}
static const struct clk_ops hi3660_stub_clk_ops = {
.recalc_rate = hi3660_stub_clk_recalc_rate,
.round_rate = hi3660_stub_clk_round_rate,
.set_rate = hi3660_stub_clk_set_rate,
};
static struct hi3660_stub_clk hi3660_stub_clks[HI3660_CLK_STUB_NUM] = {
DEFINE_CLK_STUB(HI3660_CLK_STUB_CLUSTER0, 0x0001030A, "cpu-cluster.0")
DEFINE_CLK_STUB(HI3660_CLK_STUB_CLUSTER1, 0x0002030A, "cpu-cluster.1")
DEFINE_CLK_STUB(HI3660_CLK_STUB_GPU, 0x0003030A, "clk-g3d")
DEFINE_CLK_STUB(HI3660_CLK_STUB_DDR, 0x00040309, "clk-ddrc")
};
static struct clk_hw *hi3660_stub_clk_hw_get(struct of_phandle_args *clkspec,
void *data)
{
unsigned int idx = clkspec->args[0];
if (idx >= HI3660_CLK_STUB_NUM) {
pr_err("%s: invalid index %u\n", __func__, idx);
return ERR_PTR(-EINVAL);
}
return &hi3660_stub_clks[idx].hw;
}
static int hi3660_stub_clk_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct resource *res;
unsigned int i;
int ret;
/* Use mailbox client without blocking */
stub_clk_chan.cl.dev = dev;
stub_clk_chan.cl.tx_done = NULL;
stub_clk_chan.cl.tx_block = false;
stub_clk_chan.cl.knows_txdone = false;
/* Allocate mailbox channel */
stub_clk_chan.mbox = mbox_request_channel(&stub_clk_chan.cl, 0);
if (IS_ERR(stub_clk_chan.mbox))
return PTR_ERR(stub_clk_chan.mbox);
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res)
return -EINVAL;
freq_reg = devm_ioremap(dev, res->start, resource_size(res));
if (!freq_reg)
return -ENOMEM;
freq_reg += HI3660_STUB_CLOCK_DATA;
for (i = 0; i < HI3660_CLK_STUB_NUM; i++) {
ret = devm_clk_hw_register(&pdev->dev, &hi3660_stub_clks[i].hw);
if (ret)
return ret;
}
return devm_of_clk_add_hw_provider(&pdev->dev, hi3660_stub_clk_hw_get,
hi3660_stub_clks);
}
static const struct of_device_id hi3660_stub_clk_of_match[] = {
{ .compatible = "hisilicon,hi3660-stub-clk", },
{}
};
static struct platform_driver hi3660_stub_clk_driver = {
.probe = hi3660_stub_clk_probe,
.driver = {
.name = "hi3660-stub-clk",
.of_match_table = hi3660_stub_clk_of_match,
},
};
static int __init hi3660_stub_clk_init(void)
{
return platform_driver_register(&hi3660_stub_clk_driver);
}
subsys_initcall(hi3660_stub_clk_init);