ARM: brcmstb: add infrastructure for ARM-based Broadcom STB SoCs

The BCM7xxx series of Broadcom SoCs are used primarily in set-top boxes.

This patch adds machine support for the ARM-based Broadcom SoCs.
Signed-off-by: Marc Carino <marc.ceeeee@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Matt Porter <mporter@linaro.org>

arch/arm/configs/multi_v7_defconfig

@@ -19,6 +19,7 @@ CONFIG_MACH_DOVE=y
 CONFIG_ARCH_BCM=y
 CONFIG_ARCH_BCM_MOBILE=y
 CONFIG_ARCH_BCM_5301X=y
+CONFIG_ARCH_BRCMSTB=y
 CONFIG_ARCH_BERLIN=y
 CONFIG_MACH_BERLIN_BG2=y
 CONFIG_MACH_BERLIN_BG2CD=y

arch/arm/mach-bcm/Kconfig

@@ -99,4 +99,18 @@ config ARCH_BCM_5301X
 	  different SoC or with the older BCM47XX and BCM53XX based
 	  network SoC using a MIPS CPU, they are supported by arch/mips/bcm47xx
 
+config ARCH_BRCMSTB
+	bool "Broadcom BCM7XXX based boards" if ARCH_MULTI_V7
+	depends on MMU
+	select ARM_GIC
+	select MIGHT_HAVE_PCI
+	select HAVE_SMP
+	select HAVE_ARM_ARCH_TIMER
+	help
+	  Say Y if you intend to run the kernel on a Broadcom ARM-based STB
+	  chipset.
+
+	  This enables support for Broadcom ARM-based set-top box chipsets,
+	  including the 7445 family of chips.
+
 endif

arch/arm/mach-bcm/Makefile

@@ -33,3 +33,8 @@ obj-$(CONFIG_ARCH_BCM2835)	+= board_bcm2835.o
 
 # BCM5301X
 obj-$(CONFIG_ARCH_BCM_5301X)	+= bcm_5301x.o
+
+ifeq ($(CONFIG_ARCH_BRCMSTB),y)
+obj-y				+= brcmstb.o
+obj-$(CONFIG_SMP)		+= headsmp-brcmstb.o platsmp-brcmstb.o
+endif

arch/arm/mach-bcm/brcmstb.c

+/*
+ * Copyright (C) 2013-2014 Broadcom Corporation
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/init.h>
+#include <linux/of_platform.h>
+
+#include <asm/mach-types.h>
+#include <asm/mach/arch.h>
+
+static const char *brcmstb_match[] __initconst = {
+	"brcm,bcm7445",
+	"brcm,brcmstb",
+	NULL
+};
+
+DT_MACHINE_START(BRCMSTB, "Broadcom STB (Flattened Device Tree)")
+	.dt_compat	= brcmstb_match,
+MACHINE_END

arch/arm/mach-bcm/brcmstb.h

+/*
+ * Copyright (C) 2013-2014 Broadcom Corporation
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef __BRCMSTB_H__
+#define __BRCMSTB_H__
+
+void brcmstb_secondary_startup(void);
+
+#endif /* __BRCMSTB_H__ */

arch/arm/mach-bcm/headsmp-brcmstb.S

+/*
+ * SMP boot code for secondary CPUs
+ * Based on arch/arm/mach-tegra/headsmp.S
+ *
+ * Copyright (C) 2010 NVIDIA, Inc.
+ * Copyright (C) 2013-2014 Broadcom Corporation
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <asm/assembler.h>
+#include <linux/linkage.h>
+#include <linux/init.h>
+
+        .section ".text.head", "ax"
+
+ENTRY(brcmstb_secondary_startup)
+        /*
+         * Ensure CPU is in a sane state by disabling all IRQs and switching
+         * into SVC mode.
+         */
+        setmode	PSR_I_BIT | PSR_F_BIT | SVC_MODE, r0
+
+        bl      v7_invalidate_l1
+        b       secondary_startup
+ENDPROC(brcmstb_secondary_startup)

arch/arm/mach-bcm/platsmp-brcmstb.c

+/*
+ * Broadcom STB CPU SMP and hotplug support for ARM
+ *
+ * Copyright (C) 2013-2014 Broadcom Corporation
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/printk.h>
+#include <linux/regmap.h>
+#include <linux/smp.h>
+#include <linux/mfd/syscon.h>
+#include <linux/spinlock.h>
+
+#include <asm/cacheflush.h>
+#include <asm/cp15.h>
+#include <asm/mach-types.h>
+#include <asm/smp_plat.h>
+
+#include "brcmstb.h"
+
+enum {
+	ZONE_MAN_CLKEN_MASK		= BIT(0),
+	ZONE_MAN_RESET_CNTL_MASK	= BIT(1),
+	ZONE_MAN_MEM_PWR_MASK		= BIT(4),
+	ZONE_RESERVED_1_MASK		= BIT(5),
+	ZONE_MAN_ISO_CNTL_MASK		= BIT(6),
+	ZONE_MANUAL_CONTROL_MASK	= BIT(7),
+	ZONE_PWR_DN_REQ_MASK		= BIT(9),
+	ZONE_PWR_UP_REQ_MASK		= BIT(10),
+	ZONE_BLK_RST_ASSERT_MASK	= BIT(12),
+	ZONE_PWR_OFF_STATE_MASK		= BIT(25),
+	ZONE_PWR_ON_STATE_MASK		= BIT(26),
+	ZONE_DPG_PWR_STATE_MASK		= BIT(28),
+	ZONE_MEM_PWR_STATE_MASK		= BIT(29),
+	ZONE_RESET_STATE_MASK		= BIT(31),
+	CPU0_PWR_ZONE_CTRL_REG		= 1,
+	CPU_RESET_CONFIG_REG		= 2,
+};
+
+static void __iomem *cpubiuctrl_block;
+static void __iomem *hif_cont_block;
+static u32 cpu0_pwr_zone_ctrl_reg;
+static u32 cpu_rst_cfg_reg;
+static u32 hif_cont_reg;
+
+#ifdef CONFIG_HOTPLUG_CPU
+static DEFINE_PER_CPU_ALIGNED(int, per_cpu_sw_state);
+
+static int per_cpu_sw_state_rd(u32 cpu)
+{
+	sync_cache_r(SHIFT_PERCPU_PTR(&per_cpu_sw_state, per_cpu_offset(cpu)));
+	return per_cpu(per_cpu_sw_state, cpu);
+}
+
+static void per_cpu_sw_state_wr(u32 cpu, int val)
+{
+	per_cpu(per_cpu_sw_state, cpu) = val;
+	dmb();
+	sync_cache_w(SHIFT_PERCPU_PTR(&per_cpu_sw_state, per_cpu_offset(cpu)));
+	dsb_sev();
+}
+#else
+static inline void per_cpu_sw_state_wr(u32 cpu, int val) { }
+#endif
+
+static void __iomem *pwr_ctrl_get_base(u32 cpu)
+{
+	void __iomem *base = cpubiuctrl_block + cpu0_pwr_zone_ctrl_reg;
+	base += (cpu_logical_map(cpu) * 4);
+	return base;
+}
+
+static u32 pwr_ctrl_rd(u32 cpu)
+{
+	void __iomem *base = pwr_ctrl_get_base(cpu);
+	return readl_relaxed(base);
+}
+
+static void pwr_ctrl_wr(u32 cpu, u32 val)
+{
+	void __iomem *base = pwr_ctrl_get_base(cpu);
+	writel(val, base);
+}
+
+static void cpu_rst_cfg_set(u32 cpu, int set)
+{
+	u32 val;
+	val = readl_relaxed(cpubiuctrl_block + cpu_rst_cfg_reg);
+	if (set)
+		val |= BIT(cpu_logical_map(cpu));
+	else
+		val &= ~BIT(cpu_logical_map(cpu));
+	writel_relaxed(val, cpubiuctrl_block + cpu_rst_cfg_reg);
+}
+
+static void cpu_set_boot_addr(u32 cpu, unsigned long boot_addr)
+{
+	const int reg_ofs = cpu_logical_map(cpu) * 8;
+	writel_relaxed(0, hif_cont_block + hif_cont_reg + reg_ofs);
+	writel_relaxed(boot_addr, hif_cont_block + hif_cont_reg + 4 + reg_ofs);
+}
+
+static void brcmstb_cpu_boot(u32 cpu)
+{
+	pr_info("SMP: Booting CPU%d...\n", cpu);
+
+	/*
+	 * set the reset vector to point to the secondary_startup
+	 * routine
+	 */
+	cpu_set_boot_addr(cpu, virt_to_phys(brcmstb_secondary_startup));
+
+	/* unhalt the cpu */
+	cpu_rst_cfg_set(cpu, 0);
+}
+
+static void brcmstb_cpu_power_on(u32 cpu)
+{
+	/*
+	 * The secondary cores power was cut, so we must go through
+	 * power-on initialization.
+	 */
+	u32 tmp;
+
+	pr_info("SMP: Powering up CPU%d...\n", cpu);
+
+	/* Request zone power up */
+	pwr_ctrl_wr(cpu, ZONE_PWR_UP_REQ_MASK);
+
+	/* Wait for the power up FSM to complete */
+	do {
+		tmp = pwr_ctrl_rd(cpu);
+	} while (!(tmp & ZONE_PWR_ON_STATE_MASK));
+
+	per_cpu_sw_state_wr(cpu, 1);
+}
+
+static int brcmstb_cpu_get_power_state(u32 cpu)
+{
+	int tmp = pwr_ctrl_rd(cpu);
+	return (tmp & ZONE_RESET_STATE_MASK) ? 0 : 1;
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+
+static void brcmstb_cpu_die(u32 cpu)
+{
+	v7_exit_coherency_flush(all);
+
+	/* Prevent all interrupts from reaching this CPU. */
+	arch_local_irq_disable();
+
+	/*
+	 * Final full barrier to ensure everything before this instruction has
+	 * quiesced.
+	 */
+	isb();
+	dsb();
+
+	per_cpu_sw_state_wr(cpu, 0);
+
+	/* Sit and wait to die */
+	wfi();
+
+	/* We should never get here... */
+	panic("Spurious interrupt on CPU %d received!\n", cpu);
+}
+
+static int brcmstb_cpu_kill(u32 cpu)
+{
+	u32 tmp;
+
+	pr_info("SMP: Powering down CPU%d...\n", cpu);
+
+	while (per_cpu_sw_state_rd(cpu))
+		;
+
+	/* Program zone reset */
+	pwr_ctrl_wr(cpu, ZONE_RESET_STATE_MASK | ZONE_BLK_RST_ASSERT_MASK |
+			      ZONE_PWR_DN_REQ_MASK);
+
+	/* Verify zone reset */
+	tmp = pwr_ctrl_rd(cpu);
+	if (!(tmp & ZONE_RESET_STATE_MASK))
+		pr_err("%s: Zone reset bit for CPU %d not asserted!\n",
+			__func__, cpu);
+
+	/* Wait for power down */
+	do {
+		tmp = pwr_ctrl_rd(cpu);
+	} while (!(tmp & ZONE_PWR_OFF_STATE_MASK));
+
+	/* Settle-time from Broadcom-internal DVT reference code */
+	udelay(7);
+
+	/* Assert reset on the CPU */
+	cpu_rst_cfg_set(cpu, 1);
+
+	return 1;
+}
+
+#endif /* CONFIG_HOTPLUG_CPU */
+
+static int __init setup_hifcpubiuctrl_regs(struct device_node *np)
+{
+	int rc = 0;
+	char *name;
+	struct device_node *syscon_np = NULL;
+
+	name = "syscon-cpu";
+
+	syscon_np = of_parse_phandle(np, name, 0);
+	if (!syscon_np) {
+		pr_err("can't find phandle %s\n", name);
+		rc = -EINVAL;
+		goto cleanup;
+	}
+
+	cpubiuctrl_block = of_iomap(syscon_np, 0);
+	if (!cpubiuctrl_block) {
+		pr_err("iomap failed for cpubiuctrl_block\n");
+		rc = -EINVAL;
+		goto cleanup;
+	}
+
+	rc = of_property_read_u32_index(np, name, CPU0_PWR_ZONE_CTRL_REG,
+					&cpu0_pwr_zone_ctrl_reg);
+	if (rc) {
+		pr_err("failed to read 1st entry from %s property (%d)\n", name,
+			rc);
+		rc = -EINVAL;
+		goto cleanup;
+	}
+
+	rc = of_property_read_u32_index(np, name, CPU_RESET_CONFIG_REG,
+					&cpu_rst_cfg_reg);
+	if (rc) {
+		pr_err("failed to read 2nd entry from %s property (%d)\n", name,
+			rc);
+		rc = -EINVAL;
+		goto cleanup;
+	}
+
+cleanup:
+	if (syscon_np)
+		of_node_put(syscon_np);
+
+	return rc;
+}
+
+static int __init setup_hifcont_regs(struct device_node *np)
+{
+	int rc = 0;
+	char *name;
+	struct device_node *syscon_np = NULL;
+
+	name = "syscon-cont";
+
+	syscon_np = of_parse_phandle(np, name, 0);
+	if (!syscon_np) {
+		pr_err("can't find phandle %s\n", name);
+		rc = -EINVAL;
+		goto cleanup;
+	}
+
+	hif_cont_block = of_iomap(syscon_np, 0);
+	if (!hif_cont_block) {
+		pr_err("iomap failed for hif_cont_block\n");
+		rc = -EINVAL;
+		goto cleanup;
+	}
+
+	/* offset is at top of hif_cont_block */
+	hif_cont_reg = 0;
+
+cleanup:
+	if (syscon_np)
+		of_node_put(syscon_np);
+
+	return rc;
+}
+
+static void __init brcmstb_cpu_ctrl_setup(unsigned int max_cpus)
+{
+	int rc;
+	struct device_node *np;
+	char *name;
+
+	name = "brcm,brcmstb-smpboot";
+	np = of_find_compatible_node(NULL, NULL, name);
+	if (!np) {
+		pr_err("can't find compatible node %s\n", name);
+		return;
+	}
+
+	rc = setup_hifcpubiuctrl_regs(np);
+	if (rc)
+		return;
+
+	rc = setup_hifcont_regs(np);
+	if (rc)
+		return;
+}
+
+static DEFINE_SPINLOCK(boot_lock);
+
+static void brcmstb_secondary_init(unsigned int cpu)
+{
+	/*
+	 * Synchronise with the boot thread.
+	 */
+	spin_lock(&boot_lock);
+	spin_unlock(&boot_lock);
+}
+
+static int brcmstb_boot_secondary(unsigned int cpu, struct task_struct *idle)
+{
+	/*
+	 * set synchronisation state between this boot processor
+	 * and the secondary one
+	 */
+	spin_lock(&boot_lock);
+
+	/* Bring up power to the core if necessary */
+	if (brcmstb_cpu_get_power_state(cpu) == 0)
+		brcmstb_cpu_power_on(cpu);
+
+	brcmstb_cpu_boot(cpu);
+
+	/*
+	 * now the secondary core is starting up let it run its
+	 * calibrations, then wait for it to finish
+	 */
+	spin_unlock(&boot_lock);
+
+	return 0;
+}
+
+static struct smp_operations brcmstb_smp_ops __initdata = {
+	.smp_prepare_cpus	= brcmstb_cpu_ctrl_setup,
+	.smp_secondary_init	= brcmstb_secondary_init,
+	.smp_boot_secondary	= brcmstb_boot_secondary,
+#ifdef CONFIG_HOTPLUG_CPU
+	.cpu_kill		= brcmstb_cpu_kill,
+	.cpu_die		= brcmstb_cpu_die,
+#endif
+};
+
+CPU_METHOD_OF_DECLARE(brcmstb_smp, "brcm,brahma-b15", &brcmstb_smp_ops);