linux-kernel - Re: [PATCH v7 2/7] thermal: tsens: Add support to split up register address space into two

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Message-ID: <20180717232907.GC129942@google.com>
Date:   Tue, 17 Jul 2018 16:29:07 -0700
From:   Matthias Kaehlcke <mka@...omium.org>
To:     Amit Kucheria <amit.kucheria@...aro.org>
Cc:     linux-kernel@...r.kernel.org, rnayak@...eaurora.org,
        linux-arm-msm@...r.kernel.org, bjorn.andersson@...aro.org,
        edubezval@...il.com, smohanad@...eaurora.org,
        vivek.gautam@...eaurora.org, andy.gross@...aro.org,
        dianders@...omium.org, Zhang Rui <rui.zhang@...el.com>,
        linux-pm@...r.kernel.org
Subject: Re: [PATCH v7 2/7] thermal: tsens: Add support to split up register
 address space into two

On Thu, Jul 12, 2018 at 02:09:03PM +0530, Amit Kucheria wrote:
> There are two banks of registers for v2 TSENS IPs: SROT and TM. On older
> SoCs these were contiguous, leading to DTs mapping them as one register
> address space of size 0x2000. In newer SoCs, these two banks are not
> contiguous anymore.
> 
> Add logic to init_common() to differentiate between old and new DTs and
> adjust associated offsets for the TM register bank so that the old DTs will
> continue to function correctly.
> 
> Signed-off-by: Amit Kucheria <amit.kucheria@...aro.org>
> Reviewed-by: Bjorn Andersson <bjorn.andersson@...aro.org>
> Tested-by: Matthias Kaehlcke <mka@...omium.org>
> ---
>  drivers/thermal/qcom/tsens-8996.c   |  4 ++--
>  drivers/thermal/qcom/tsens-common.c | 12 ++++++++++++
>  drivers/thermal/qcom/tsens.h        |  1 +
>  3 files changed, 15 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/thermal/qcom/tsens-8996.c b/drivers/thermal/qcom/tsens-8996.c
> index e1f7781..3e60cec 100644
> --- a/drivers/thermal/qcom/tsens-8996.c
> +++ b/drivers/thermal/qcom/tsens-8996.c
> @@ -16,7 +16,7 @@
>  #include <linux/regmap.h>
>  #include "tsens.h"
>  
> -#define STATUS_OFFSET	0x10a0
> +#define STATUS_OFFSET	0xa0
>  #define LAST_TEMP_MASK	0xfff
>  #define STATUS_VALID_BIT	BIT(21)
>  #define CODE_SIGN_BIT		BIT(11)
> @@ -28,7 +28,7 @@ static int get_temp_8996(struct tsens_device *tmdev, int id, int *temp)
>  	unsigned int sensor_addr;
>  	int last_temp = 0, last_temp2 = 0, last_temp3 = 0, ret;
>  
> -	sensor_addr = STATUS_OFFSET + s->hw_id * 4;
> +	sensor_addr = tmdev->tm_offset + STATUS_OFFSET + s->hw_id * 4;
>  	ret = regmap_read(tmdev->map, sensor_addr, &code);
>  	if (ret)
>  		return ret;
> diff --git a/drivers/thermal/qcom/tsens-common.c b/drivers/thermal/qcom/tsens-common.c
> index b1449ad..c22dc18 100644
> --- a/drivers/thermal/qcom/tsens-common.c
> +++ b/drivers/thermal/qcom/tsens-common.c
> @@ -16,6 +16,7 @@
>  #include <linux/io.h>
>  #include <linux/nvmem-consumer.h>
>  #include <linux/of_address.h>
> +#include <linux/of_platform.h>
>  #include <linux/platform_device.h>
>  #include <linux/regmap.h>
>  #include "tsens.h"
> @@ -126,11 +127,22 @@ static const struct regmap_config tsens_config = {
>  int __init init_common(struct tsens_device *tmdev)
>  {
>  	void __iomem *base;
> +	struct platform_device *op = of_find_device_by_node(tmdev->dev->of_node);
>  
> +	if (!op)
> +		return -EINVAL;
>  	base = of_iomap(tmdev->dev->of_node, 0);
>  	if (!base)
>  		return -EINVAL;
>  
> +	/* The driver only uses the TM register address space for now */
> +	if (op->num_resources > 1) {
> +		tmdev->tm_offset = 0;
> +	} else {
> +		/* old DTs where SROT and TM were in a contiguous 2K block */
> +		tmdev->tm_offset = 0x1000;
> +	}

nit: no curly braces for conditionals with a single statement. There
is probably no need to respin just for this though.

Reviewed-by: Matthias Kaehlcke <mka@...omium.org>