Re: [PATCH V3] cpufreq: imx6q: read OCOTP through nvmem for imx6ul/imx6ull

From: Viresh Kumar
Date: Mon Oct 08 2018 - 02:04:33 EST


On 08-10-18, 09:10, Anson Huang wrote:
> On i.MX6UL/i.MX6ULL, accessing OCOTP directly is wrong because
> the ocotp clock needs to be enabled first. Add support for reading
> OCOTP through the nvmem API, and keep the old method there to
> support old dtb.
>
> Signed-off-by: Anson Huang <Anson.Huang@xxxxxxx>
> ---
> changes since V2:
> Add put node when reading ocotp register done.
> drivers/cpufreq/imx6q-cpufreq.c | 53 ++++++++++++++++++++++++++++-------------
> 1 file changed, 36 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/cpufreq/imx6q-cpufreq.c b/drivers/cpufreq/imx6q-cpufreq.c
> index b2ff423..38b67f8 100644
> --- a/drivers/cpufreq/imx6q-cpufreq.c
> +++ b/drivers/cpufreq/imx6q-cpufreq.c
> @@ -12,6 +12,7 @@
> #include <linux/cpu_cooling.h>
> #include <linux/err.h>
> #include <linux/module.h>
> +#include <linux/nvmem-consumer.h>
> #include <linux/of.h>
> #include <linux/of_address.h>
> #include <linux/pm_opp.h>
> @@ -290,20 +291,33 @@ static void imx6q_opp_check_speed_grading(struct device *dev)
> #define OCOTP_CFG3_6ULL_SPEED_792MHZ 0x2
> #define OCOTP_CFG3_6ULL_SPEED_900MHZ 0x3
>
> -static void imx6ul_opp_check_speed_grading(struct device *dev)
> +static int imx6ul_opp_check_speed_grading(struct device *dev)
> {
> - struct device_node *np;
> - void __iomem *base;
> u32 val;
> + int ret = 0;
>
> - np = of_find_compatible_node(NULL, NULL, "fsl,imx6ul-ocotp");
> - if (!np)
> - return;
> + if (of_find_property(dev->of_node, "nvmem-cells", NULL)) {
> + ret = nvmem_cell_read_u32(dev, "speed_grade", &val);
> + if (ret)
> + return ret;
> + } else {
> + struct device_node *np;
> + void __iomem *base;
> +
> + np = of_find_compatible_node(NULL, NULL, "fsl,imx6ul-ocotp");
> + if (!np)
> + return -ENOENT;
> +
> + base = of_iomap(np, 0);

You could have done of_node_put(np); right here and remove the below two calls
to the same.

> + if (!base) {
> + dev_err(dev, "failed to map ocotp\n");
> + of_node_put(np);
> + return -EFAULT;
> + }
>
> - base = of_iomap(np, 0);
> - if (!base) {
> - dev_err(dev, "failed to map ocotp\n");
> - goto put_node;
> + val = readl_relaxed(base + OCOTP_CFG3);
> + iounmap(base);
> + of_node_put(np);
> }

--
viresh