| Message ID | 56bbd0a4-5ec0-7af1-eed5-c93e2a81b677@gmail.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v2,1/2] riscv: Try to get cpu frequency from device tree | expand |
On Mon, Feb 3, 2020 at 1:40 AM Sean Anderson <seanga2 at gmail.com> wrote: > > The cpu clock is probably already enabled if we are executing code > (though we could be executing from a different core). This patch > prevents the cpu clock or its parents from being disabled. > > Signed-off-by: Sean Anderson <seanga2 at gmail.com> > --- > This doesn't strictly depend on the previous patch, but it doesn't > make too much sense without it. > > Changes for v2: > - New > drivers/cpu/riscv_cpu.c | 20 ++++++++++++++++++++ > 1 file changed, 20 insertions(+) > Reviewed-by: Bin Meng <bmeng.cn at gmail.com> I believe both 2 patches in this series are needed by "riscv: Add Sipeed Maix support" series? If yes, I think you can just put 2 patches into the same series, to give people a good context next time. Regards, Bin
diff --git a/drivers/cpu/riscv_cpu.c b/drivers/cpu/riscv_cpu.c index 5309a49e60..52b74d9e69 100644 --- a/drivers/cpu/riscv_cpu.c +++ b/drivers/cpu/riscv_cpu.c @@ -1,6 +1,7 @@ // SPDX-License-Identifier: GPL-2.0+ /* * Copyright (C) 2018, Bin Meng <bmeng.cn at gmail.com> + * Copyright (C) 2020, Sean Anderson <seanga2 at gmail.com> */ #include <clk.h> @@ -116,6 +117,24 @@ static int riscv_cpu_bind(struct udevice *dev) return 0; } +static int riscv_cpu_probe(struct udevice *dev) +{ + int ret = 0; + struct clk clk; + + /* Get a clock if it exists */ + ret = clk_get_by_index(dev, 0, &clk); + if (ret) + return 0; + + ret = clk_enable(&clk); + clk_free(&clk); + if (ret == -ENOSYS || ret == -ENOTSUPP) + return 0; + else + return ret; +} + static const struct cpu_ops riscv_cpu_ops = { .get_desc = riscv_cpu_get_desc, .get_info = riscv_cpu_get_info, @@ -132,6 +151,7 @@ U_BOOT_DRIVER(riscv_cpu) = { .id = UCLASS_CPU, .of_match = riscv_cpu_ids, .bind = riscv_cpu_bind, + .probe = riscv_cpu_probe, .ops = &riscv_cpu_ops, .flags = DM_FLAG_PRE_RELOC, };
The cpu clock is probably already enabled if we are executing code (though we could be executing from a different core). This patch prevents the cpu clock or its parents from being disabled. Signed-off-by: Sean Anderson <seanga2 at gmail.com> --- This doesn't strictly depend on the previous patch, but it doesn't make too much sense without it. Changes for v2: - New drivers/cpu/riscv_cpu.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+)