| Message ID | 20210604172742.10593-5-stephan@gerhold.net |
|---|---|
| State | Accepted |
| Commit | 5e57e5d0d62216502ce603f3399e411368e11a43 |
| Headers | show |
| Series | [1/5] arm64: dts: qcom: msm8916-samsung-a2015: Add touch key | expand |
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 > (NFC_CLK_REQ or BB_CLK2_REQ). > > 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 <krzysztof.kozlowski@canonical.com> > Signed-off-by: Stephan Gerhold <stephan@gerhold.net> > --- > .../qcom/msm8916-samsung-a2015-common.dtsi | 64 +++++++++++++++++++ > 1 file changed, 64 insertions(+) > Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com> Best regards, Krzysztof
diff --git a/arch/arm64/boot/dts/qcom/msm8916-samsung-a2015-common.dtsi b/arch/arm64/boot/dts/qcom/msm8916-samsung-a2015-common.dtsi index 9a6988ded29d..9b4b7de7cec2 100644 --- a/arch/arm64/boot/dts/qcom/msm8916-samsung-a2015-common.dtsi +++ b/arch/arm64/boot/dts/qcom/msm8916-samsung-a2015-common.dtsi @@ -4,6 +4,7 @@ #include <dt-bindings/gpio/gpio.h> #include <dt-bindings/input/input.h> #include <dt-bindings/interrupt-controller/irq.h> +#include <dt-bindings/pinctrl/qcom,pmic-gpio.h> / { aliases { @@ -124,6 +125,34 @@ touchkey: touchkey@20 { pinctrl-0 = <&tkey_default>; }; }; + + i2c-nfc { + compatible = "i2c-gpio"; + sda-gpios = <&msmgpio 0 (GPIO_ACTIVE_HIGH|GPIO_OPEN_DRAIN)>; + scl-gpios = <&msmgpio 1 (GPIO_ACTIVE_HIGH|GPIO_OPEN_DRAIN)>; + + pinctrl-names = "default"; + pinctrl-0 = <&nfc_i2c_default>; + + #address-cells = <1>; + #size-cells = <0>; + + nfc@27 { + compatible = "samsung,s3fwrn5-i2c"; + reg = <0x27>; + + interrupt-parent = <&msmgpio>; + interrupts = <21 IRQ_TYPE_EDGE_RISING>; + + en-gpios = <&msmgpio 20 GPIO_ACTIVE_HIGH>; + wake-gpios = <&msmgpio 49 GPIO_ACTIVE_HIGH>; + + clocks = <&rpmcc RPM_SMD_BB_CLK2_PIN>; + + pinctrl-names = "default"; + pinctrl-0 = <&nfc_default &nfc_clk_req>; + }; + }; }; &blsp_i2c2 { @@ -384,6 +413,30 @@ muic_int_default: muic-int-default { bias-disable; }; + nfc_default: nfc-default { + pins = "gpio20", "gpio49"; + function = "gpio"; + + drive-strength = <2>; + bias-disable; + + irq { + pins = "gpio21"; + function = "gpio"; + + drive-strength = <2>; + bias-pull-down; + }; + }; + + nfc_i2c_default: nfc-i2c-default { + pins = "gpio0", "gpio1"; + function = "gpio"; + + drive-strength = <2>; + bias-disable; + }; + tkey_default: tkey-default { pins = "gpio98"; function = "gpio"; @@ -408,3 +461,14 @@ tsp_en_default: tsp-en-default { bias-disable; }; }; + +&pm8916_gpios { + nfc_clk_req: nfc-clk-req { + pins = "gpio2"; + function = "func1"; + + input-enable; + bias-disable; + power-source = <PM8916_GPIO_L2>; + }; +};
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 (NFC_CLK_REQ or BB_CLK2_REQ). 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 <krzysztof.kozlowski@canonical.com> Signed-off-by: Stephan Gerhold <stephan@gerhold.net> --- .../qcom/msm8916-samsung-a2015-common.dtsi | 64 +++++++++++++++++++ 1 file changed, 64 insertions(+)