Msm8953 For Arm64 Driver

Let’s demonstrate a simple virtual character driver for MSM8953 on ARM64. This logs the CPU architecture at insmod time.

// msm8953_arm64_dummy.c
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
static int __init dummy_init(void)
#ifdef CONFIG_ARM64
pr_info("MSM8953 ARM64 driver loaded on 64-bit kernel\n");
#else
pr_info("MSM8953 driver loaded on non-ARM64 kernel (check config)\n");
#endif
return 0;

static void __exit dummy_exit(void)
pr_info("MSM8953 ARM64 driver unloaded\n");

module_init(dummy_init);
module_exit(dummy_exit);
MODULE_LICENSE("GPL");
 msm8953 for arm64 driver

Makefile for ARM64 cross-compilation:

obj-m += msm8953_arm64_dummy.o
KERNELDIR ?= ~/android/kernel/msm-4.9
CROSS_COMPILE := aarch64-linux-android-
CC := $(CROSS_COMPILE)gcc Let’s demonstrate a simple virtual character driver for
all:
make -C $(KERNELDIR) M=$(PWD) ARCH=arm64 modules
clean:
make -C $(KERNELDIR) M=$(PWD) ARCH=arm64 clean

Build and test on an MSM8953 device running an ARM64 kernel. #endif return 0

No. While Qualcomm has mainlined support for many 8xx series, MSM8953 is not fully supported in the upstream Linux kernel. The mainline qcom_defconfig lacks:

However, mainline boot is possible with a minimal Device Tree (arch/arm64/boot/dts/qcom/msm8953.dtsi exists upstream but is incomplete). Projects like postmarketOS and Mainline Linux on MSM8953 are slowly closing the gap.

This is the nightmare. The MSM8953 uses a custom Qualcomm LPA (Low Power Audio) or SLIMbus layout with a WCD9335/WCD9340 codec.