From mboxrd@z Thu Jan 1 00:00:00 1970 From: wens@csie.org (Chen-Yu Tsai) Date: Wed, 18 Mar 2015 11:24:01 +0800 Subject: [PATCH 2/3] ARM: sun8i: Add SMP support for the Allwinner A23 In-Reply-To: <1426649042-30547-1-git-send-email-wens@csie.org> References: <1426649042-30547-1-git-send-email-wens@csie.org> Message-ID: <1426649042-30547-3-git-send-email-wens@csie.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 --- We can't use of_io_request_and_map() here, as it will conflict with PRCM, and leave us without a serial console. I think a proper way to solve this would be a syscon device or something like the mfd-simple device posted by Arnd. --- Documentation/devicetree/bindings/arm/cpus.txt | 1 + arch/arm/mach-sunxi/platsmp.c | 69 ++++++++++++++++++++++++++ 2 files changed, 70 insertions(+) diff --git a/Documentation/devicetree/bindings/arm/cpus.txt b/Documentation/devicetree/bindings/arm/cpus.txt index 8b9e0a95de31..40202d85b132 100644 --- a/Documentation/devicetree/bindings/arm/cpus.txt +++ b/Documentation/devicetree/bindings/arm/cpus.txt @@ -188,6 +188,7 @@ nodes to be present and contain the properties described below. # On ARM 32-bit systems this property is optional and can be one of: "allwinner,sun6i-a31" + "allwinner,sun8i-a23" "arm,psci" "brcm,brahma-b15" "marvell,armada-375-smp" diff --git a/arch/arm/mach-sunxi/platsmp.c b/arch/arm/mach-sunxi/platsmp.c index 587b0468efcc..e8483ec79d67 100644 --- a/arch/arm/mach-sunxi/platsmp.c +++ b/arch/arm/mach-sunxi/platsmp.c @@ -121,3 +121,72 @@ static struct smp_operations sun6i_smp_ops __initdata = { .smp_boot_secondary = sun6i_smp_boot_secondary, }; CPU_METHOD_OF_DECLARE(sun6i_a31_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_a23_smp, "allwinner,sun8i-a23", &sun8i_smp_ops); -- 2.1.4