[PATCH] cpufreq: qcom-hw: Fix reading "reg" with address/size-cells != 2

From: Konrad Dybcio
Date: Fri Dec 09 2022 - 10:08:35 EST


Commit 054a3ef683a1 ("cpufreq: qcom-hw: Allocate qcom_cpufreq_data during
probe") assumed that every reg variable is 4*u32 wide (as most new qcom
SoCs set #address- and #size-cells to <2>. That is not the case for all of
them though. Check the cells values dynamically to ensure the proper
region of the DTB is being read.

Fixes: 054a3ef683a1 ("cpufreq: qcom-hw: Allocate qcom_cpufreq_data during probe")
Signed-off-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxx>
---
drivers/cpufreq/qcom-cpufreq-hw.c | 20 ++++++++++++++++++--
1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/drivers/cpufreq/qcom-cpufreq-hw.c b/drivers/cpufreq/qcom-cpufreq-hw.c
index 340fed35e45d..22f48f789557 100644
--- a/drivers/cpufreq/qcom-cpufreq-hw.c
+++ b/drivers/cpufreq/qcom-cpufreq-hw.c
@@ -649,9 +649,10 @@ static int qcom_cpufreq_hw_driver_probe(struct platform_device *pdev)
{
struct clk_hw_onecell_data *clk_data;
struct device *dev = &pdev->dev;
+ struct device_node *soc_node;
struct device *cpu_dev;
struct clk *clk;
- int ret, i, num_domains;
+ int ret, i, num_domains, reg_sz;

clk = clk_get(dev, "xo");
if (IS_ERR(clk))
@@ -679,7 +680,22 @@ static int qcom_cpufreq_hw_driver_probe(struct platform_device *pdev)
return ret;

/* Allocate qcom_cpufreq_data based on the available frequency domains in DT */
- num_domains = of_property_count_elems_of_size(dev->of_node, "reg", sizeof(u32) * 4);
+ soc_node = of_get_parent(dev->of_node);
+ if (!soc_node)
+ return -EINVAL;
+
+ ret = of_property_read_u32(soc_node, "#address-cells", &reg_sz);
+ if (ret)
+ return ret;
+
+ /* Reuse 'i', as it's only used later in the loop */
+ ret = of_property_read_u32(soc_node, "#size-cells", &i);
+ if (ret)
+ return ret;
+
+ reg_sz += i;
+
+ num_domains = of_property_count_elems_of_size(dev->of_node, "reg", sizeof(u32) * reg_sz);
if (num_domains <= 0)
return num_domains;

--
2.38.1