diff options
Diffstat (limited to 'drivers/clk/hisilicon/clk-hi3660-stub.c')
| -rw-r--r-- | drivers/clk/hisilicon/clk-hi3660-stub.c | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/drivers/clk/hisilicon/clk-hi3660-stub.c b/drivers/clk/hisilicon/clk-hi3660-stub.c new file mode 100644 index 000000000000..9b6c72bbddf9 --- /dev/null +++ b/drivers/clk/hisilicon/clk-hi3660-stub.c @@ -0,0 +1,185 @@ +/* + * 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); + 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); |