ARM: omap4: add OMAP support for the fiq debugger

Due to platform limitations, it only currently supports IRQ-only
fiq debugger.

Change-Id: I95508183a40793e1220769e34305bbe9fb6ede4e
Signed-off-by: Dima Zavin <dima@android.com>

4 files changed, 358 insertions, 0 deletions

diff --git a/arch/arm/mach-omap2/Kconfig b/arch/arm/mach-omap2/Kconfig
index 1cf7d51..fe0bed4 100644
--- a/arch/arm/mach-omap2/Kconfig
+++ b/arch/arm/mach-omap2/Kconfig
@@ -356,6 +356,13 @@ config OMAP_ALLOW_OSWR
 	  Which means the Logic of power domains can be lost now
 	  unlike the CSWR wherein the logic is retained
 
+config OMAP_FIQ_DEBUGGER
+	bool "Enable the serial FIQ debugger on OMAP"
+	default y
+	select FIQ_DEBUGGER
+	help
+	  Enables the serial FIQ debugger on OMAP"
+
 endmenu
 
 endif
diff --git a/arch/arm/mach-omap2/Makefile b/arch/arm/mach-omap2/Makefile
index c0f2be2..b4049d3 100644
--- a/arch/arm/mach-omap2/Makefile
+++ b/arch/arm/mach-omap2/Makefile
@@ -292,3 +292,4 @@ obj-y					+= common-board-devices.o
 obj-$(CONFIG_OMAP_REMOTE_PROC)		+= remoteproc.o
 obj-$(CONFIG_OMAP_HSI_DEVICE)		+= omap_hsi.o
 obj-$(CONFIG_ARCH_OMAP4)		+= omap_dmm.o
+obj-$(CONFIG_OMAP_FIQ_DEBUGGER)		+= omap_fiq_debugger.o
diff --git a/arch/arm/mach-omap2/include/mach/omap_fiq_debugger.h b/arch/arm/mach-omap2/include/mach/omap_fiq_debugger.h
new file mode 100644
index 0000000..c49608e
--- /dev/null
+++ b/arch/arm/mach-omap2/include/mach/omap_fiq_debugger.h
@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2011 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#ifndef __MACH_OMAP_FIQ_DEBUGGER_H
+#define __MACH_OMAP_FIQ_DEBUGGER_H
+
+#ifdef CONFIG_OMAP_FIQ_DEBUGGER
+int __init omap_serial_debug_init(int id, bool is_fiq, bool is_high_prio_irq,
+				  struct omap_device_pad *pads, int num_pads);
+u32 omap_debug_uart_resume_idle(void);
+
+#else
+static inline int __init omap_serial_debug_init(int id, bool is_fiq, bool is_high_prio_irq,
+				  struct omap_device_pad *pads, int num_pads)
+{
+}
+
+static inline u32 omap_debug_uart_resume_idle(void)
+{
+	return 0;
+}
+#endif
+
+#endif
diff --git a/arch/arm/mach-omap2/omap_fiq_debugger.c b/arch/arm/mach-omap2/omap_fiq_debugger.c
new file mode 100644
index 0000000..7fff162
--- /dev/null
+++ b/arch/arm/mach-omap2/omap_fiq_debugger.c
@@ -0,0 +1,315 @@
+/*
+ * Serial Debugger Interface for Omap
+ *
+ * Copyright (C) 2011 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/clk.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/serial_reg.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/stacktrace.h>
+#include <linux/uaccess.h>
+
+#include <plat/omap_device.h>
+#include <plat/omap-pm.h>
+#include <plat/omap-serial.h>
+
+#include <asm/fiq_debugger.h>
+
+#include <mach/omap_fiq_debugger.h>
+#include <mach/system.h>
+
+#include "mux.h"
+
+struct omap_fiq_debugger {
+	struct fiq_debugger_pdata pdata;
+	struct platform_device *pdev;
+	void __iomem *debug_port_base;
+	bool suspended;
+	spinlock_t lock;
+};
+
+static struct omap_fiq_debugger *dbgs[OMAP_MAX_HSUART_PORTS];
+
+static inline struct omap_fiq_debugger *get_dbg(struct platform_device *pdev)
+{
+	struct fiq_debugger_pdata *pdata = dev_get_platdata(&pdev->dev);
+	return container_of(pdata, struct omap_fiq_debugger, pdata);
+}
+
+static inline void omap_write(struct omap_fiq_debugger *dbg,
+			       unsigned int val, unsigned int off)
+{
+	__raw_writel(val, dbg->debug_port_base + off * 4);
+}
+
+static inline unsigned int omap_read(struct omap_fiq_debugger *dbg,
+				      unsigned int off)
+{
+	return __raw_readl(dbg->debug_port_base + off * 4);
+}
+
+static void debug_omap_port_enable(struct platform_device *pdev)
+{
+	pm_runtime_get_sync(&pdev->dev);
+}
+
+static void debug_omap_port_disable(struct platform_device *pdev)
+{
+	struct omap_fiq_debugger *dbg = get_dbg(pdev);
+	unsigned long flags;
+
+	spin_lock_irqsave(&dbg->lock, flags);
+	if (!dbg->suspended) {
+		pm_runtime_mark_last_busy(&pdev->dev);
+		pm_runtime_put_autosuspend(&pdev->dev);
+	} else {
+		pm_runtime_put_sync_suspend(&pdev->dev);
+	}
+	spin_unlock_irqrestore(&dbg->lock, flags);
+}
+
+static int debug_omap_port_resume(struct platform_device *pdev)
+{
+	struct omap_fiq_debugger *dbg = get_dbg(pdev);
+
+	dbg->suspended = false;
+	barrier();
+	return 0;
+}
+
+static int debug_omap_port_suspend(struct platform_device *pdev)
+{
+	struct omap_fiq_debugger *dbg = get_dbg(pdev);
+	unsigned long flags;
+
+	/* this will force the device to be idle'd now, in case it was
+	 * autosuspended but timer has not yet run out.
+	 */
+	spin_lock_irqsave(&dbg->lock, flags);
+	dbg->suspended = true;
+	pm_runtime_get_sync(&pdev->dev);
+	pm_runtime_put_sync_suspend(&pdev->dev);
+	spin_unlock_irqrestore(&dbg->lock, flags);
+
+	return 0;
+}
+
+static int debug_port_config(struct omap_fiq_debugger *dbg)
+{
+	if (omap_read(dbg, UART_LSR) & UART_LSR_DR)
+		omap_read(dbg, UART_RX);
+
+	/* enable rx and lsr interrupt */
+	omap_write(dbg, UART_IER_RLSI | UART_IER_RDI, UART_IER);
+
+	/* interrupt on every character */
+	omap_write(dbg, 0, UART_IIR);
+
+	omap_write(dbg, 0, UART_OMAP_WER);
+
+	return 0;
+}
+
+u32 omap_debug_uart_resume_idle(void)
+{
+	int i;
+	u32 ret = 0;
+
+	for (i = 0; i < OMAP_MAX_HSUART_PORTS; i++) {
+		struct omap_fiq_debugger *dbg = dbgs[i];
+		struct omap_device *od;
+
+		if (!dbg || !dbg->pdev)
+			continue;
+
+		od = to_omap_device(dbg->pdev);
+		if (omap_hwmod_pad_get_wakeup_status(od->hwmods[0])) {
+			/*
+			 * poke the uart and let it stay on long enough
+			 * to process any further data. It's ok to use
+			 * autosuspend here since this is on the resume path
+			 * during the wakeup. We'll still go through a full
+			 * resume cycle, so if we go back to suspend
+			 * the suspended flag will properly get reset.
+			 */
+			pm_runtime_get_sync(&dbg->pdev->dev);
+			pm_runtime_mark_last_busy(&dbg->pdev->dev);
+			pm_runtime_put_autosuspend(&dbg->pdev->dev);
+			dev_dbg(&dbg->pdev->dev, "woke up from IO pad\n");
+			ret++;
+		}
+	}
+
+	return ret;
+}
+
+static int debug_port_init(struct platform_device *pdev)
+{
+	struct omap_fiq_debugger *dbg = get_dbg(pdev);
+
+	device_init_wakeup(&pdev->dev, true);
+
+	pm_runtime_use_autosuspend(&pdev->dev);
+	pm_runtime_set_autosuspend_delay(&pdev->dev, DEFAULT_AUTOSUSPEND_DELAY);
+
+	pm_runtime_enable(&pdev->dev);
+	pm_runtime_irq_safe(&pdev->dev);
+
+	omap_hwmod_idle(to_omap_device(pdev)->hwmods[0]);
+	debug_omap_port_enable(pdev);
+	debug_omap_port_disable(pdev);
+
+	debug_omap_port_enable(pdev);
+
+	if (device_may_wakeup(&pdev->dev))
+		omap_hwmod_enable_wakeup(to_omap_device(pdev)->hwmods[0]);
+
+	debug_port_config(dbg);
+
+	debug_omap_port_disable(pdev);
+	return 0;
+}
+
+static int debug_getc(struct platform_device *pdev)
+{
+	struct omap_fiq_debugger *dbg = get_dbg(pdev);
+	unsigned int lsr;
+	int ret = FIQ_DEBUGGER_NO_CHAR;
+
+	lsr = omap_read(dbg, UART_LSR);
+	if (lsr & UART_LSR_BI) {
+		/* need to read RHR to clear the BI condition */
+		omap_read(dbg, UART_RX);
+		ret = FIQ_DEBUGGER_BREAK;
+	} else if (lsr & UART_LSR_DR) {
+		ret = omap_read(dbg, UART_RX);
+	}
+
+	return ret;
+}
+
+static void debug_putc(struct platform_device *pdev, unsigned int c)
+{
+	struct omap_fiq_debugger *dbg = get_dbg(pdev);
+
+	while (!(omap_read(dbg, UART_LSR) & UART_LSR_THRE))
+		cpu_relax();
+
+	omap_write(dbg, c, UART_TX);
+}
+
+static void debug_flush(struct platform_device *pdev)
+{
+	struct omap_fiq_debugger *dbg = get_dbg(pdev);
+
+	while (!(omap_read(dbg, UART_LSR) & UART_LSR_TEMT))
+		cpu_relax();
+}
+
+static int uart_idle_hwmod(struct omap_device *od)
+{
+	omap_hwmod_idle(od->hwmods[0]);
+
+	return 0;
+}
+
+static int uart_enable_hwmod(struct omap_device *od)
+{
+	omap_hwmod_enable(od->hwmods[0]);
+
+	return 0;
+}
+
+static struct omap_device_pm_latency omap_uart_latency[] = {
+	{
+		.deactivate_func = uart_idle_hwmod,
+		.activate_func	 = uart_enable_hwmod,
+		.flags = OMAP_DEVICE_LATENCY_AUTO_ADJUST,
+	},
+};
+
+extern struct omap_hwmod *omap_uart_hwmod_lookup(int num);
+
+int __init omap_serial_debug_init(int id, bool is_fiq, bool is_high_prio_irq,
+				  struct omap_device_pad *pads, int num_pads)
+{
+	struct omap_fiq_debugger *dbg;
+	struct omap_hwmod *oh;
+	struct omap_device *od;
+	int ret;
+
+	if (id >= OMAP_MAX_HSUART_PORTS)
+		return -EINVAL;
+	if (dbgs[id])
+		return -EBUSY;
+
+	oh = omap_uart_hwmod_lookup(id);
+	if (!oh)
+		return -ENODEV;
+
+	oh->mpu_irqs[0].name = "uart_irq";
+	oh->mux = omap_hwmod_mux_init(pads, num_pads);
+
+	dbg = kzalloc(sizeof(struct omap_fiq_debugger), GFP_KERNEL);
+	if (!dbg) {
+		pr_err("Failed to allocate for fiq debugger\n");
+		return -ENOMEM;
+	}
+
+	dbg->debug_port_base = ioremap(oh->slaves[0]->addr[0].pa_start,
+				       PAGE_SIZE);
+	if (!dbg->debug_port_base) {
+		pr_err("Failed to ioremap for fiq debugger\n");
+		ret = -ENOMEM;
+		goto err_ioremap;
+	}
+
+	spin_lock_init(&dbg->lock);
+
+	dbg->pdata.uart_init = debug_port_init;
+	dbg->pdata.uart_getc = debug_getc;
+	dbg->pdata.uart_putc = debug_putc;
+	dbg->pdata.uart_flush = debug_flush;
+	dbg->pdata.uart_enable = debug_omap_port_enable;
+	dbg->pdata.uart_disable = debug_omap_port_disable;
+	dbg->pdata.uart_dev_suspend = debug_omap_port_suspend;
+	dbg->pdata.uart_dev_resume = debug_omap_port_resume;
+
+	od = omap_device_build("fiq_debugger", id,
+			       oh, dbg, sizeof(*dbg), omap_uart_latency,
+			       ARRAY_SIZE(omap_uart_latency), false);
+	if (IS_ERR(od)) {
+		pr_err("Could not build omap_device for fiq_debugger: %s\n",
+		       oh->name);
+		ret = PTR_ERR(od);
+		goto err_dev_build;
+	}
+
+	dbg->pdev = &od->pdev;
+	dbgs[id] = dbg;
+
+	return 0;
+
+err_dev_build:
+	iounmap(dbg->debug_port_base);
+err_ioremap:
+	kfree(dbg);
+	return ret;
+}