From patchwork Sun Feb 2 17:38:05 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Anderson X-Patchwork-Id: 235778 List-Id: U-Boot discussion From: seanga2 at gmail.com (Sean Anderson) Date: Sun, 2 Feb 2020 12:38:05 -0500 Subject: [PATCH v2 1/2] riscv: Try to get cpu frequency from device tree Message-ID: Instead of always using the "clock-frequency" property to determine cpu frequency, try using a clock in "clocks" if it exists. This patch also fixes a bug where there could be spurious higher frequencies if sizeof(u32) != sizeof(ulong). Signed-off-by: Sean Anderson Reviewed-by: Bin Meng --- This patch is the combination of the patches https://patchwork.ozlabs.org/patch/1223933/ https://patchwork.ozlabs.org/patch/1224957/ "riscv: Fix incorrect cpu frequency on RV64" "riscv: Try to get cpu frequency from device tree" Changes for v2: - Renamed err to ret drivers/cpu/riscv_cpu.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) diff --git a/drivers/cpu/riscv_cpu.c b/drivers/cpu/riscv_cpu.c index 28ad0aa30f..5309a49e60 100644 --- a/drivers/cpu/riscv_cpu.c +++ b/drivers/cpu/riscv_cpu.c @@ -3,6 +3,7 @@ * Copyright (C) 2018, Bin Meng */ +#include #include #include #include @@ -27,9 +28,24 @@ static int riscv_cpu_get_desc(struct udevice *dev, char *buf, int size) static int riscv_cpu_get_info(struct udevice *dev, struct cpu_info *info) { + int ret; + struct clk clk; const char *mmu; - dev_read_u32(dev, "clock-frequency", (u32 *)&info->cpu_freq); + /* Zero out the frequency, in case sizeof(ulong) != sizeof(u32) */ + info->cpu_freq = 0; + + /* First try getting the frequency from the assigned clock */ + ret = clk_get_by_index(dev, 0, &clk); + if (!ret) { + ret = clk_get_rate(&clk); + if (!IS_ERR_VALUE(ret)) + info->cpu_freq = ret; + clk_free(&clk); + } + + if (!info->cpu_freq) + dev_read_u32(dev, "clock-frequency", (u32 *)&info->cpu_freq); mmu = dev_read_string(dev, "mmu-type"); if (!mmu) From patchwork Sun Feb 2 17:39:57 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Anderson X-Patchwork-Id: 235779 List-Id: U-Boot discussion From: seanga2 at gmail.com (Sean Anderson) Date: Sun, 2 Feb 2020 12:39:57 -0500 Subject: [PATCH v2 2/2] riscv: Enable cpu clock if it is present In-Reply-To: References: Message-ID: <56bbd0a4-5ec0-7af1-eed5-c93e2a81b677@gmail.com> 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 Reviewed-by: Bin Meng --- 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(+) 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 + * Copyright (C) 2020, Sean Anderson */ #include @@ -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, };