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From: Krzysztof Kozlowski <>
To: Stephan Gerhold <>,
	Bjorn Andersson <>
Cc: Andy Gross <>,,,,
	Michael Srba <>
Subject: Re: [PATCH 5/5] arm64: dts: qcom: msm8916-samsung-a2015: Add NFC
Date: Mon, 7 Jun 2021 10:23:24 +0200	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <>

On 04/06/2021 19:27, Stephan Gerhold wrote:
> The Samsung Galaxy A3/A5 both have a Samsung S3FWRN5 NFC chip that
> works quite well with the s3fwrn5 driver in the Linux NFC subsystem.
> The clock setup for the NFC chip is a bit special (although this
> seems to be a common approach used for Qualcomm devices with NFC):
> The NFC chip has an output GPIO that is asserted whenever the clock
> is needed to function properly. On the A3/A5 this is wired up to
> PM8916 GPIO2, which is then configured with a special function
> Enabling the rpmcc RPM_SMD_BB_CLK2_PIN clock will then instruct
> PM8916 to automatically enable the clock whenever the NFC chip
> requests it. The advantage is that the clock is only enabled when
> needed and we don't need to manage it ourselves from the NFC driver.
> Note that for some reason Samsung decided to connect the I2C pins
> to GPIOs where no hardware I2C bus is available, so we need to
> fall back to software bit-banging with i2c-gpio.
> Cc: Krzysztof Kozlowski <>
> Signed-off-by: Stephan Gerhold <>
> ---
>  .../qcom/msm8916-samsung-a2015-common.dtsi    | 64 +++++++++++++++++++
>  1 file changed, 64 insertions(+)

Acked-by: Krzysztof Kozlowski <>

Best regards,

  reply	other threads:[~2021-06-07  8:23 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-04 17:27 [PATCH 1/5] arm64: dts: qcom: msm8916-samsung-a2015: Add touch key Stephan Gerhold
2021-06-04 17:27 ` [PATCH 2/5] arm64: dts: qcom: msm8916-samsung-a3u: Add touch key regulators Stephan Gerhold
2021-06-04 17:27 ` [PATCH 3/5] arm64: dts: qcom: msm8916-samsung-a5u: Add touch key regulator Stephan Gerhold
2021-06-04 17:27 ` [PATCH 4/5] arm64: dts: qcom: msm8916-samsung-a2015: Add rt5033 battery Stephan Gerhold
2021-06-04 17:27 ` [PATCH 5/5] arm64: dts: qcom: msm8916-samsung-a2015: Add NFC Stephan Gerhold
2021-06-07  8:23   ` Krzysztof Kozlowski [this message]
2021-06-10 14:50 ` [PATCH 1/5] arm64: dts: qcom: msm8916-samsung-a2015: Add touch key patchwork-bot+linux-arm-msm

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