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Subject: Re: [RFT][PATCH 2/2] regulator: lm363x: Fix n_voltages setting for
 lm36274
To:     Axel Lin <axel.lin@ingics.com>, Mark Brown <broonie@kernel.org>
CC:     Liam Girdwood <lgirdwood@gmail.com>, <linux-kernel@vger.kernel.org>
References: <20190626132632.32629-1-axel.lin@ingics.com>
 <20190626132632.32629-2-axel.lin@ingics.com>
From:   Dan Murphy <dmurphy@ti.com>
Message-ID: <e1ba816f-1ecc-acc1-1f69-bc474da1061a@ti.com>
Date:   Wed, 26 Jun 2019 10:06:49 -0500
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Hello

On 6/26/19 8:26 AM, Axel Lin wrote:
> According to the datasheet http://www.ti.com/lit/ds/symlink/lm36274.pdf:
> Table 23. VPOS Bias Register Field Descriptions VPOS[5:0]:
> VPOS voltage (50-mV steps): VPOS = 4 V + (Code × 50 mV), 6.5 V max
> 000000 = 4 V
> 000001 = 4.05 V
> :
> 011110 = 5.5 V (Default)
> :
> 110010 = 6.5 V
> 110011 to 111111 map to 6.5 V
>
> So the LM36274_LDO_VSEL_MAX should be 0b110010 (0x32).
> The valid selectors are 0 ... LM36274_LDO_VSEL_MAX, n_voltages should be
> LM36274_LDO_VSEL_MAX + 1. Similarly, the n_voltages should be
> LM36274_BOOST_VSEL_MAX + 1 for LM36274_BOOST.
>
> Fixes: bff5e8071533 ("regulator: lm363x: Add support for LM36274")
> Signed-off-by: Axel Lin <axel.lin@ingics.com>
> ---
>   drivers/regulator/lm363x-regulator.c | 8 ++++----
>   1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/regulator/lm363x-regulator.c b/drivers/regulator/lm363x-regulator.c
> index e4a27d63bf90..4b9f618b07e9 100644
> --- a/drivers/regulator/lm363x-regulator.c
> +++ b/drivers/regulator/lm363x-regulator.c
> @@ -36,7 +36,7 @@
>   
>   /* LM36274 */
>   #define LM36274_BOOST_VSEL_MAX		0x3f
> -#define LM36274_LDO_VSEL_MAX		0x34
> +#define LM36274_LDO_VSEL_MAX		0x32

This does not seem correct the max number of voltages are 0x34.

The register is zero based so you can have 33 voltage select levels and 
+ 1 is 34 total selectors

Liam/Mark correct me if I am incorrect.

Dan


>   #define LM36274_VOLTAGE_MIN		4000000
>   
>   /* Common */
> @@ -226,7 +226,7 @@ static const struct regulator_desc lm363x_regulator_desc[] = {
>   		.of_match	= "vboost",
>   		.id             = LM36274_BOOST,
>   		.ops            = &lm363x_boost_voltage_table_ops,
> -		.n_voltages     = LM36274_BOOST_VSEL_MAX,
> +		.n_voltages     = LM36274_BOOST_VSEL_MAX + 1,
>   		.min_uV         = LM36274_VOLTAGE_MIN,
>   		.uV_step        = LM363X_STEP_50mV,
>   		.type           = REGULATOR_VOLTAGE,
> @@ -239,7 +239,7 @@ static const struct regulator_desc lm363x_regulator_desc[] = {
>   		.of_match	= "vpos",
>   		.id             = LM36274_LDO_POS,
>   		.ops            = &lm363x_regulator_voltage_table_ops,
> -		.n_voltages     = LM36274_LDO_VSEL_MAX,
> +		.n_voltages     = LM36274_LDO_VSEL_MAX + 1,
>   		.min_uV         = LM36274_VOLTAGE_MIN,
>   		.uV_step        = LM363X_STEP_50mV,
>   		.type           = REGULATOR_VOLTAGE,
> @@ -254,7 +254,7 @@ static const struct regulator_desc lm363x_regulator_desc[] = {
>   		.of_match	= "vneg",
>   		.id             = LM36274_LDO_NEG,
>   		.ops            = &lm363x_regulator_voltage_table_ops,
> -		.n_voltages     = LM36274_LDO_VSEL_MAX,
> +		.n_voltages     = LM36274_LDO_VSEL_MAX + 1,
>   		.min_uV         = LM36274_VOLTAGE_MIN,
>   		.uV_step        = LM363X_STEP_50mV,
>   		.type           = REGULATOR_VOLTAGE,