linux-imx: Add P3H2840 GPIO controller support for SE051 NFC mode#1
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bperseghetti wants to merge 3 commits intolf-6.12.20-2.0.0-walnascar-navq95from
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linux-imx: Add P3H2840 GPIO controller support for SE051 NFC mode#1bperseghetti wants to merge 3 commits intolf-6.12.20-2.0.0-walnascar-navq95from
bperseghetti wants to merge 3 commits intolf-6.12.20-2.0.0-walnascar-navq95from
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Add kernel patches to enable GPIO control of SE051C2 secure element power for NFC energy harvesting mode on NavQ95. Changes: - 0007: Add gpio_chip support to P3H2840 I3C hub driver - Exposes target port SCL/SDA pins as GPIO lines - GPIO 0-7 = SCL (TP0-TP7), GPIO 8-15 = SDA (TP0-TP7) - 0008: Configure TP0 as GPIO mode in imx95-navqb device tree - SE_ENABLE signal connected to TP0 SDA (GPIO 8) - Pull low to enable NFC energy harvesting mode Usage: gpioset p3h2x4x-gpio 8=0 # Enable NFC mode gpioset p3h2x4x-gpio 8=1 # Enable I2C mode Signed-off-by: Benjamin Perseghetti <bperseghetti@rudislabs.com>
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Add kernel patch to enable I2C bus recovery for the P3H2840 I3C hub. This implements the standard 9-SCL-pulse bus clear procedure as documented in the P3H2840 datasheet section 8.2.4. The SE051C2 secure element can leave SDA stuck LOW when switching between NFC and I2C modes during active NFC communication. This recovery mechanism allows userspace to clear the stuck bus via sysfs. Changes: - 0009: Add bus recovery functions and sysfs interface - p3h2x4x_tp_check_bus_stuck(): Check SCL/SDA status - p3h2x4x_tp_bus_recover(): Perform 9-SCL-pulse recovery - /sys/devices/.../bus_status_tpN: Read bus status - /sys/devices/.../bus_recover_tpN: Trigger recovery Usage: cat /sys/devices/.../bus_status_tp5 echo 1 > /sys/devices/.../bus_recover_tp5 Signed-off-by: Benjamin Perseghetti <bperseghetti@rudislabs.com>
The 0008 patch incorrectly changed TP0 from smbus to gpio mode, assuming SE_ENABLE was on GPIO 8 (TP0 SDA). However, SE_ENABLE is actually connected to GPIO line 2 (TP2 SCL), and TP2 was already configured as GPIO mode in the upstream DTS. This patch was unnecessary and may have caused interference with devices that were using TP0 for SMBus communication. Signed-off-by: Benjamin Perseghetti <bperseghetti@rudislabs.com>
| + * | ||
| + * Return: 1 if SDA is stuck LOW, 0 if bus is OK, negative on error | ||
| + */ | ||
| +int p3h2x4x_tp_check_bus_stuck(struct p3h2x4x_i3c_hub_dev *hub, int tp) |
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@bperseghetti could you use the Linux build-in recovery api instead?
https://github.com/torvalds/linux/blob/fcb70a56f4d81450114034b2c61f48ce7444a0e2/include/linux/i2c.h#L655
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Add kernel patches to enable GPIO control of SE051C2 secure element power for NFC energy harvesting mode on NavQ95.
Changes:
Usage:
gpioset p3h2x4x-gpio 8=0 # Enable NFC mode
gpioset p3h2x4x-gpio 8=1 # Enable I2C mode