On Fri, Nov 17, 2017 at 05:27:31PM +0800, Xu YiPing wrote: > From: Kaihua Zhong <[email protected]> > > Hi3660 has four stub clocks, which are big and LITTLE cluster clocks, > GPU clock and DDR clock. These clocks ask MCU for frequency scaling > by sending message through mailbox. > > This commit adds support for stub clocks, it requests the dedicated > mailbox channel at initialization; then later uses this channel to send > message to MCU to execute frequency scaling. The four stub clocks share > the same mailbox channel, but every stub clock has its own command id so > MCU can distinguish the requirement coming for which clock. > > A shared memory is used to present effective frequency value, so the > clock driver uses I/O mapping for the memory and reads back rate value.
Hi Michael, Stephen, Could you help review this patch? > Reviewed-by: Leo Yan <[email protected]> > Signed-off-by: Kai Zhao <[email protected]> > Signed-off-by: Tao Wang <[email protected]> > Signed-off-by: Ruyi Wang <[email protected]> > Signed-off-by: Kaihua Zhong <[email protected]> > --- > drivers/clk/hisilicon/Kconfig | 6 ++ > drivers/clk/hisilicon/Makefile | 1 + > drivers/clk/hisilicon/clk-hi3660-stub.c | 186 > ++++++++++++++++++++++++++++++++ > 3 files changed, 193 insertions(+) > create mode 100644 drivers/clk/hisilicon/clk-hi3660-stub.c > > diff --git a/drivers/clk/hisilicon/Kconfig b/drivers/clk/hisilicon/Kconfig > index 7098bfd..1bd4355 100644 > --- a/drivers/clk/hisilicon/Kconfig > +++ b/drivers/clk/hisilicon/Kconfig > @@ -49,3 +49,9 @@ config STUB_CLK_HI6220 > default ARCH_HISI > help > Build the Hisilicon Hi6220 stub clock driver. > + > +config STUB_CLK_HI3660 > + bool "Hi3660 Stub Clock Driver" > + depends on COMMON_CLK_HI3660 && MAILBOX > + help > + Build the Hisilicon Hi3660 stub clock driver. > diff --git a/drivers/clk/hisilicon/Makefile b/drivers/clk/hisilicon/Makefile > index 1e4c3dd..0a5b499 100644 > --- a/drivers/clk/hisilicon/Makefile > +++ b/drivers/clk/hisilicon/Makefile > @@ -14,3 +14,4 @@ obj-$(CONFIG_COMMON_CLK_HI3798CV200) += > crg-hi3798cv200.o > obj-$(CONFIG_COMMON_CLK_HI6220) += clk-hi6220.o > obj-$(CONFIG_RESET_HISI) += reset.o > obj-$(CONFIG_STUB_CLK_HI6220) += clk-hi6220-stub.o > +obj-$(CONFIG_STUB_CLK_HI3660) += clk-hi3660-stub.o > diff --git a/drivers/clk/hisilicon/clk-hi3660-stub.c > b/drivers/clk/hisilicon/clk-hi3660-stub.c > new file mode 100644 > index 0000000..607efa4 > --- /dev/null > +++ b/drivers/clk/hisilicon/clk-hi3660-stub.c > @@ -0,0 +1,186 @@ > +/* > + * Hisilicon clock driver > + * > + * Copyright (c) 2013-2017 Hisilicon Limited. > + * Copyright (c) 2017 Linaro Limited. > + * > + * Author: Kai Zhao <[email protected]> > + * Tao Wang <[email protected]> > + * Leo Yan <[email protected]> > + * > + * 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 (IS_ERR(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; > + } > + > + ret = of_clk_add_hw_provider(pdev->dev.of_node, hi3660_stub_clk_hw_get, > + hi3660_stub_clks); > + return ret; > +} > + > +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); > -- > 1.9.1 >
