[PATCH 20/22] ARM: sun8i: Add SMP support for the Allwinner A23

Chen-Yu Tsai
2014-05-23T08:39:53Z

The A23 is a dual Cortex-A7. Add the logic to use the IPs used to
control the CPU configuration and the CPU power so that we can
bring up secondary CPUs at boot.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
---
arch/arm/mach-sunxi/platsmp.c | 69 +++++++++++++++++++++++++++++++++++++++++++
1 file changed, 69 insertions(+)

diff --git a/arch/arm/mach-sunxi/platsmp.c b/arch/arm/mach-sunxi/platsmp.c
index c53077b..688faaf 100644
--- a/arch/arm/mach-sunxi/platsmp.c
+++ b/arch/arm/mach-sunxi/platsmp.c
@@ -121,3 +121,72 @@ struct smp_operations sun6i_smp_ops __initdata = {
.smp_boot_secondary = sun6i_smp_boot_secondary,
};
CPU_METHOD_OF_DECLARE(sun6i_smp, "allwinner,sun6i-a31", &sun6i_smp_ops);
+
+static void __init sun8i_smp_prepare_cpus(unsigned int max_cpus)
+{
+ struct device_node *node;
+
+ node = of_find_compatible_node(NULL, NULL, "allwinner,sun8i-a23-prcm");
+ if (!node) {
+ pr_err("Missing A23 PRCM node in the device tree\n");
+ return;
+ }
+
+ prcm_membase = of_iomap(node, 0);
+ if (!prcm_membase) {
+ pr_err("Couldn't map A23 PRCM registers\n");
+ return;
+ }
+
+ node = of_find_compatible_node(NULL, NULL,
+ "allwinner,sun8i-a23-cpuconfig");
+ if (!node) {
+ pr_err("Missing A23 CPU config node in the device tree\n");
+ return;
+ }
+
+ cpucfg_membase = of_iomap(node, 0);
+ if (!cpucfg_membase)
+ pr_err("Couldn't map A23 CPU config registers\n");
+
+}
+
+static int sun8i_smp_boot_secondary(unsigned int cpu,
+ struct task_struct *idle)
+{
+ u32 reg;
+
+ if (!(prcm_membase && cpucfg_membase))
+ return -EFAULT;
+
+ spin_lock(&cpu_lock);
+
+ /* Set CPU boot address */
+ writel(virt_to_phys(secondary_startup),
+ cpucfg_membase + CPUCFG_PRIVATE0_REG);
+
+ /* Assert the CPU core in reset */
+ writel(0, cpucfg_membase + CPUCFG_CPU_RST_CTRL_REG(cpu));
+
+ /* Assert the L1 cache in reset */
+ reg = readl(cpucfg_membase + CPUCFG_GEN_CTRL_REG);
+ writel(reg & ~BIT(cpu), cpucfg_membase + CPUCFG_GEN_CTRL_REG);
+
+ /* Clear CPU power-off gating */
+ reg = readl(prcm_membase + PRCM_CPU_PWROFF_REG);
+ writel(reg & ~BIT(cpu), prcm_membase + PRCM_CPU_PWROFF_REG);
+ mdelay(1);
+
+ /* Deassert the CPU core reset */
+ writel(3, cpucfg_membase + CPUCFG_CPU_RST_CTRL_REG(cpu));
+
+ spin_unlock(&cpu_lock);
+
+ return 0;
+}
+
+struct smp_operations sun8i_smp_ops __initdata = {
+ .smp_prepare_cpus = sun8i_smp_prepare_cpus,
+ .smp_boot_secondary = sun8i_smp_boot_secondary,
+};
+CPU_METHOD_OF_DECLARE(sun8i_smp, "allwinner,sun8i-a23", &sun8i_smp_ops);
--
2.0.0.rc2