[RFC 1/2] powerpc/5200: add general purpose timer API for the MPC5200

[RFC 1/2] powerpc/5200: add general purpose timer API for the MPC5200

[Grant Likely]

From: Grant Likely <grant.likely@secretlab.ca>

This patch adds an interface for controlling the timer function of the
MPC5200 GPT devices.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
---

This probably isn't complete, but I wanted to get it out there and reviewed
before I commit to the design.  Comments appreciated.

g.

 arch/powerpc/include/asm/mpc52xx.h        |    7 ++
 arch/powerpc/platforms/52xx/mpc52xx_gpt.c |  132 +++++++++++++++++++++++++++--
 2 files changed, 129 insertions(+), 10 deletions(-)


diff --git a/arch/powerpc/include/asm/mpc52xx.h b/arch/powerpc/include/asm/mpc52xx.h
index 81a2393..8273357 100644
--- a/arch/powerpc/include/asm/mpc52xx.h
+++ b/arch/powerpc/include/asm/mpc52xx.h
@@ -275,6 +275,13 @@ extern void mpc52xx_map_common_devices(void);
 extern int mpc52xx_set_psc_clkdiv(int psc_id, int clkdiv);
 extern void mpc52xx_restart(char *cmd);
 
+/* mpc52xx_gpt.c */
+struct mpc52xx_gpt_priv;
+extern struct mpc52xx_gpt_priv *mpc52xx_gpt_from_irq(int irq);
+extern int mpc52xx_gpt_start_timer(struct mpc52xx_gpt_priv *gpt, int period,
+                            int continuous);
+extern void mpc52xx_gpt_stop_timer(struct mpc52xx_gpt_priv *gpt);
+
 /* mpc52xx_pic.c */
 extern void mpc52xx_init_irq(void);
 extern unsigned int mpc52xx_get_irq(void);
diff --git a/arch/powerpc/platforms/52xx/mpc52xx_gpt.c b/arch/powerpc/platforms/52xx/mpc52xx_gpt.c
index bfbcd41..e9e040f 100644
--- a/arch/powerpc/platforms/52xx/mpc52xx_gpt.c
+++ b/arch/powerpc/platforms/52xx/mpc52xx_gpt.c
@@ -46,9 +46,12 @@
  * the output mode.  This driver does not change the output mode setting.
  */
 
+#include <linux/device.h>
 #include <linux/irq.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
+#include <linux/list.h>
+#include <linux/mutex.h>
 #include <linux/of.h>
 #include <linux/of_platform.h>
 #include <linux/of_gpio.h>
@@ -68,16 +71,21 @@ MODULE_LICENSE("GPL");
  * @irqhost: Pointer to irq_host instance; used when IRQ mode is supported
  */
 struct mpc52xx_gpt_priv {
+	struct list_head list;		/* List of all GPT devices */
 	struct device *dev;
 	struct mpc52xx_gpt __iomem *regs;
 	spinlock_t lock;
 	struct irq_host *irqhost;
+	u32 ipb_freq;
 
 #if defined(CONFIG_GPIOLIB)
 	struct of_gpio_chip of_gc;
 #endif
 };
 
+LIST_HEAD(mpc52xx_gpt_list);
+DEFINE_MUTEX(mpc52xx_gpt_list_mutex);
+
 #define MPC52xx_GPT_MODE_MS_MASK	(0x07)
 #define MPC52xx_GPT_MODE_MS_IC		(0x01)
 #define MPC52xx_GPT_MODE_MS_OC		(0x02)
@@ -88,6 +96,9 @@ struct mpc52xx_gpt_priv {
 #define MPC52xx_GPT_MODE_GPIO_OUT_LOW	(0x20)
 #define MPC52xx_GPT_MODE_GPIO_OUT_HIGH	(0x30)
 
+#define MPC52xx_GPT_MODE_COUNTER_ENABLE	(0x1000)
+#define MPC52xx_GPT_MODE_CONTINUOUS	(0x0400)
+#define MPC52xx_GPT_MODE_OPEN_DRAIN	(0x0200)
 #define MPC52xx_GPT_MODE_IRQ_EN		(0x0100)
 
 #define MPC52xx_GPT_MODE_ICT_MASK	(0x030000)
@@ -190,7 +201,7 @@ static int mpc52xx_gpt_irq_xlate(struct irq_host *h, struct device_node *ct,
 
 	dev_dbg(gpt->dev, "%s: flags=%i\n", __func__, intspec[0]);
 
-	if ((intsize < 1) || (intspec[0] < 1) || (intspec[0] > 3)) {
+	if ((intsize < 1) || (intspec[0] > 3)) {
 		dev_err(gpt->dev, "bad irq specifier in %s\n", ct->full_name);
 		return -EINVAL;
 	}
@@ -211,13 +222,11 @@ mpc52xx_gpt_irq_setup(struct mpc52xx_gpt_priv *gpt, struct device_node *node)
 {
 	int cascade_virq;
 	unsigned long flags;
-
-	/* Only setup cascaded IRQ if device tree claims the GPT is
-	 * an interrupt controller */
-	if (!of_find_property(node, "interrupt-controller", NULL))
-		return;
+	u32 mode;
 
 	cascade_virq = irq_of_parse_and_map(node, 0);
+	if (!cascade_virq)
+		return;
 
 	gpt->irqhost = irq_alloc_host(node, IRQ_HOST_MAP_LINEAR, 1,
 				      &mpc52xx_gpt_irq_ops, -1);
@@ -227,14 +236,16 @@ mpc52xx_gpt_irq_setup(struct mpc52xx_gpt_priv *gpt, struct device_node *node)
 	}
 
 	gpt->irqhost->host_data = gpt;
-
 	set_irq_data(cascade_virq, gpt);
 	set_irq_chained_handler(cascade_virq, mpc52xx_gpt_irq_cascade);
 
-	/* Set to Input Capture mode */
+	/* If the GPT is currently disabled, then change it to be in Input
+	 * Capture mode.  If the mode is non-zero, then the pin could be
+	 * already in use for something. */
 	spin_lock_irqsave(&gpt->lock, flags);
-	clrsetbits_be32(&gpt->regs->mode, MPC52xx_GPT_MODE_MS_MASK,
-			MPC52xx_GPT_MODE_MS_IC);
+	mode = in_be32(&gpt->regs->mode);
+	if ((mode & MPC52xx_GPT_MODE_MS_MASK) == 0)
+		out_be32(&gpt->regs->mode, mode | MPC52xx_GPT_MODE_MS_IC);
 	spin_unlock_irqrestore(&gpt->lock, flags);
 
 	dev_dbg(gpt->dev, "%s() complete. virq=%i\n", __func__, cascade_virq);
@@ -335,6 +346,102 @@ static void
 mpc52xx_gpt_gpio_setup(struct mpc52xx_gpt_priv *p, struct device_node *np) { }
 #endif /* defined(CONFIG_GPIOLIB) */
 
+/***********************************************************************
+ * Timer API
+ */
+
+/**
+ * mpc52xx_gpt_from_irq - Return the GPT device associated with an IRQ number
+ * @irq: irq of timer.
+ */
+struct mpc52xx_gpt_priv *mpc52xx_gpt_from_irq(int irq)
+{
+	struct mpc52xx_gpt_priv *gpt;
+	struct list_head *pos;
+
+	/* Iterate over the list of timers looking for a matching device */
+	mutex_lock(&mpc52xx_gpt_list_mutex);
+	list_for_each(pos, &mpc52xx_gpt_list) {
+		gpt = container_of(pos, struct mpc52xx_gpt_priv, list);
+		if (gpt->irqhost && irq == irq_linear_revmap(gpt->irqhost, 0)) {
+			mutex_unlock(&mpc52xx_gpt_list_mutex);
+			return gpt;
+		}
+	}
+	mutex_unlock(&mpc52xx_gpt_list_mutex);
+
+	return NULL;
+}
+EXPORT_SYMBOL(mpc52xx_gpt_from_irq);
+
+/**
+ * mpc52xx_gpt_start_timer - Set and enable the GPT timer
+ * @gpt: Pointer to gpt private data structure
+ * @period: period of timer
+ * @continuous: set to 1 to make timer continuous free running
+ *
+ * An interrupt will be generated every time the timer fires
+ */
+int mpc52xx_gpt_start_timer(struct mpc52xx_gpt_priv *gpt, int period,
+                            int continuous)
+{
+	u32 clear, set;
+	//u64 clocks;
+	u32 clocks;
+	u32 count, prescale;
+	unsigned long flags;
+
+	clear = MPC52xx_GPT_MODE_MS_MASK | MPC52xx_GPT_MODE_CONTINUOUS;
+	set = MPC52xx_GPT_MODE_MS_GPIO | MPC52xx_GPT_MODE_COUNTER_ENABLE;
+	if (continuous)
+		set |= MPC52xx_GPT_MODE_CONTINUOUS;
+
+	/* Determine the number of clocks in the requested period.  64 bit
+	 * arithmatic is done here to preserve the precision until the value
+	 * is scaled back down into the u32 range.  Period is in 'ns', bus
+	 * frequency is in Hz. */
+	//clocks = (u64)period * (u64)gpt->ipb_freq;
+	//clocks = clocks / 1000000000; /* Scale it down to ns range */
+	clocks = (period / 1000) * (gpt->ipb_freq / 1000000);
+
+	/* This device cannot handle a clock count greater than 32 bits */
+	if (clocks > 0xffffffff)
+		return -EINVAL;
+
+	/* Calculate the prescaler and count values from the clocks value.
+	 * 'clocks' is the number of clock ticks in the period.  The timer
+	 * has 16 bit precision and a 16 bit prescaler.  Prescaler is
+	 * calculated by integer dividing the clocks by 0x10000 (shifting
+	 * down 16 bits) to obtain the smallest possible divisor for clocks
+	 * to get a 16 bit count value.
+	 *
+	 * Note: the prescale register is '1' based, not '0' based.  ie. a
+	 * value of '1' means divide the clock by one.  0xffff divides the
+	 * clock by 0xffff.  '0x0000' does not divide by zero, but wraps
+	 * around and divides by 0x10000.  That is why prescale must be
+	 * a u32 variable, not a u16, for this calculation. */
+	prescale = (clocks >> 16) + 1;
+	count = clocks / prescale;
+	if (count > 0xffff)
+		pr_err("calculation error; count:%x prescale:%x clocks:%x\n",
+		       count, prescale, clocks);
+
+	/* Set and enable the timer */
+	spin_lock_irqsave(&gpt->lock, flags);
+	out_be32(&gpt->regs->count, prescale << 16 | count);
+	clrsetbits_be32(&gpt->regs->mode, clear, set);
+	spin_unlock_irqrestore(&gpt->lock, flags);
+
+	return 0;
+}
+EXPORT_SYMBOL(mpc52xx_gpt_start_timer);
+
+void mpc52xx_gpt_stop_timer(struct mpc52xx_gpt_priv *gpt)
+{
+	clrbits32(&gpt->regs->mode, MPC52xx_GPT_MODE_COUNTER_ENABLE);
+}
+EXPORT_SYMBOL(mpc52xx_gpt_stop_timer);
+
 /* ---------------------------------------------------------------------
  * of_platform bus binding code
  */
@@ -349,6 +456,7 @@ static int __devinit mpc52xx_gpt_probe(struct of_device *ofdev,
 
 	spin_lock_init(&gpt->lock);
 	gpt->dev = &ofdev->dev;
+	gpt->ipb_freq = mpc52xx_find_ipb_freq(ofdev->node);
 	gpt->regs = of_iomap(ofdev->node, 0);
 	if (!gpt->regs) {
 		kfree(gpt);
@@ -360,6 +468,10 @@ static int __devinit mpc52xx_gpt_probe(struct of_device *ofdev,
 	mpc52xx_gpt_gpio_setup(gpt, ofdev->node);
 	mpc52xx_gpt_irq_setup(gpt, ofdev->node);
 
+	mutex_lock(&mpc52xx_gpt_list_mutex);
+	list_add(&gpt->list, &mpc52xx_gpt_list);
+	mutex_unlock(&mpc52xx_gpt_list_mutex);
+
 	return 0;
 }
 

[RFC 2/2] powerpc/5200: add LocalPlus bus FIFO device driver

[Grant Likely]

From: Grant Likely <grant.likely@secretlab.ca>

This is a driver for the LocalPlus bus FIFO device

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
---

This also isn't complete, but I wanted to get it out there and reviewed
before I commit to the design.  Comments appreciated.

g.

 arch/powerpc/include/asm/mpc52xx.h            |   11 +
 arch/powerpc/platforms/52xx/Kconfig           |    4 
 arch/powerpc/platforms/52xx/Makefile          |    1 
 arch/powerpc/platforms/52xx/mpc52xx_lpbfifo.c |  282 +++++++++++++++++++++++++
 4 files changed, 298 insertions(+), 0 deletions(-)
 create mode 100644 arch/powerpc/platforms/52xx/mpc52xx_lpbfifo.c


diff --git a/arch/powerpc/include/asm/mpc52xx.h b/arch/powerpc/include/asm/mpc52xx.h
index 8273357..7ec34ea 100644
--- a/arch/powerpc/include/asm/mpc52xx.h
+++ b/arch/powerpc/include/asm/mpc52xx.h
@@ -282,6 +282,17 @@ extern int mpc52xx_gpt_start_timer(struct mpc52xx_gpt_priv *gpt, int period,
                             int continuous);
 extern void mpc52xx_gpt_stop_timer(struct mpc52xx_gpt_priv *gpt);
 
+/* mpc52xx_lpbfifo.c */
+extern int mpc52xx_lpbfifo_write(void *src, unsigned int cs,
+				 size_t offset, size_t size, int flags,
+				 void (*callback)(void *, size_t, int),
+				 void *callback_data);
+extern int mpc52xx_lpbfifo_read(void *dest, unsigned int cs,
+				size_t offset, size_t size, int flags,
+				void (*callback)(void *, size_t, int),
+				void *callback_data);
+extern void mpc52xx_lpbfifo_abort(void *callback_data);
+
 /* mpc52xx_pic.c */
 extern void mpc52xx_init_irq(void);
 extern unsigned int mpc52xx_get_irq(void);
diff --git a/arch/powerpc/platforms/52xx/Kconfig b/arch/powerpc/platforms/52xx/Kconfig
index 0465e5b..f117e23 100644
--- a/arch/powerpc/platforms/52xx/Kconfig
+++ b/arch/powerpc/platforms/52xx/Kconfig
@@ -61,3 +61,7 @@ config PPC_MPC5200_GPIO
 	select GENERIC_GPIO
 	help
 	  Enable gpiolib support for mpc5200 based boards
+
+config PPC_MPC5200_LPBFIFO
+	tristate "MPC5200 LocalPlus bus FIFO driver"
+	depends on PPC_MPC52xx
diff --git a/arch/powerpc/platforms/52xx/Makefile b/arch/powerpc/platforms/52xx/Makefile
index bfd4f52..2bc8cd0 100644
--- a/arch/powerpc/platforms/52xx/Makefile
+++ b/arch/powerpc/platforms/52xx/Makefile
@@ -15,3 +15,4 @@ ifeq ($(CONFIG_PPC_LITE5200),y)
 endif
 
 obj-$(CONFIG_PPC_MPC5200_GPIO)	+= mpc52xx_gpio.o
+obj-$(CONFIG_PPC_MPC5200_LPBFIFO)	+= mpc52xx_lpbfifo.o
diff --git a/arch/powerpc/platforms/52xx/mpc52xx_lpbfifo.c b/arch/powerpc/platforms/52xx/mpc52xx_lpbfifo.c
new file mode 100644
index 0000000..b00d763
--- /dev/null
+++ b/arch/powerpc/platforms/52xx/mpc52xx_lpbfifo.c
@@ -0,0 +1,282 @@
+/*
+ * LocalPlus Bus FIFO driver for the Freescale MPC52xx.
+ *
+ * Copyright (C) 2009 Secret Lab Technologies Ltd.
+ *
+ * This file is licensed under the terms of the GNU General Public License
+ * version 2. This program is licensed "as is" without any warranty of any
+ * kind, whether express or implied.
+ *
+ */
+
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/spinlock.h>
+#include <asm/io.h>
+#include <asm/prom.h>
+#include <asm/mpc52xx.h>
+
+MODULE_AUTHOR("Grant Likely <grant.likely@secretlab.ca>");
+MODULE_DESCRIPTION("MPC5200 LocalPlus FIFO device driver");
+MODULE_LICENSE("GPL");
+
+#define LPBFIFO_REG_PACKET_SIZE		(0x00)
+#define LPBFIFO_REG_START_ADDRESS	(0x04)
+#define LPBFIFO_REG_CONTROL		(0x08)
+#define LPBFIFO_REG_ENABLE		(0x0C)
+#define LPBFIFO_REG_BYTES_DONE_STATUS	(0x14)
+#define LPBFIFO_REG_FIFO_DATA		(0x40)
+#define LPBFIFO_REG_FIFO_STATUS		(0x44)
+#define LPBFIFO_REG_FIFO_CONTROL	(0x48)
+#define LPBFIFO_REG_FIFO_ALARM		(0x4C)
+
+struct mpc52xx_lpbfifo {
+	struct device *dev;
+	void __iomem *regs;
+	int irq;
+	spinlock_t lock;
+
+	/* Current transfer data */
+	void *data;
+	int cs;
+	size_t offset;
+	size_t size;
+	size_t remaining;
+	void (*callback)(void *, size_t, int);
+	void *callback_data;
+};
+
+/* The MPC5200 has only one fifo, so only need one instance structure */
+static struct mpc52xx_lpbfifo lpbfifo;
+
+/**
+ * mpc52xx_lpbfifo_kick - Trigger the next block of data to be transfered
+ */
+static void mpc52xx_lpbfifo_kick(void)
+{
+	size_t transfer_size = lpbfifo.remaining;
+
+	/* While the FIFO can be setup for transfer sizes as large as 16M-1,
+	 * the FIFO itself is only 512 bytes deep and it does not generate
+	 * interrupts for FIFO full events (only transfer complete will
+	 * raise an IRQ).  Therefore when not using Bestcomm to drive the
+	 * FIFO it needs to either be polled, or transfers need to constrained
+	 * to the size of the fifo.
+	 *
+	 * Here we choose to restrict the size of the transfer
+	 */
+	if (transfer_size > 512)
+		transfer_size = 512;
+
+	/* Set and clear the reset bits; is good practice in User Manual */
+	out_be32(lpbfifo.regs + LPBFIFO_REG_ENABLE, 0x01010000);
+	out_be32(lpbfifo.regs + LPBFIFO_REG_ENABLE, 0x00000301);
+
+	/* Set transfer size, width, chip select and READ mode */
+	out_be32(lpbfifo.regs + LPBFIFO_REG_PACKET_SIZE, transfer_size);
+	out_be32(lpbfifo.regs + LPBFIFO_REG_CONTROL,
+		 lpbfifo.cs << 24 | 0x00010008);
+
+	/* Kick it off */
+	out_8(lpbfifo.regs + LPBFIFO_REG_PACKET_SIZE, 0x01);
+}
+
+/**
+ * mpc52xx_lpbfifo_irq - IRQ handler for LPB FIFO
+ */
+static irqreturn_t mpc52xx_lpbfifo_irq(int irq, void *dev_id)
+{
+	u8 status = in_8(lpbfifo.regs + LPBFIFO_REG_BYTES_DONE_STATUS);
+	u32 *data;
+	int count, i;
+	void (*callback)(void *, size_t, int);
+	void *callback_data;
+
+	spin_lock(&lpbfifo.lock);
+
+	if (status & 0x10) { /* check abort bit */
+		out_be32(lpbfifo.regs + LPBFIFO_REG_ENABLE, 0x01010000);
+	} else if (status & 0x01) { /* check transaction done bit */
+		/* Read result from hardware */
+		count = in_be32(lpbfifo.regs + LPBFIFO_REG_BYTES_DONE_STATUS);
+		count &= 0x00ffffff;
+
+		data = lpbfifo.data;
+		for (i = 0; i < count; i += 4)
+			*data++ = in_be32(lpbfifo.regs + LPBFIFO_REG_FIFO_DATA);
+
+		/* Update transfer position and count */
+		lpbfifo.remaining -= count;
+		lpbfifo.offset += count;
+		lpbfifo.data += count;
+
+		/* Clear the IRQ */
+		out_8(lpbfifo.regs + LPBFIFO_REG_BYTES_DONE_STATUS, 0x01);
+
+		if (lpbfifo.remaining) {
+			/* More work to do.  Kick of the next block and exit */
+			mpc52xx_lpbfifo_kick();
+			spin_unlock(&lpbfifo.lock);
+			return IRQ_HANDLED;
+		}
+	}
+
+	/* Mark the FIFO as idle */
+	lpbfifo.data = NULL;
+	callback = lpbfifo.callback;
+	callback_data = lpbfifo.callback_data;
+	count = lpbfifo.size - lpbfifo.remaining;
+
+	/* Release the lock before calling out to the callback. */
+	spin_unlock(&lpbfifo.lock);
+
+	/* If control reaches this point then the transfer is finished,
+	 * either normal completion or due to abort */
+	callback(callback_data, count, (status & 0x10) != 0);
+
+	return IRQ_HANDLED;
+}
+
+/**
+ * mpc52xx_lpbfifo_read - Initiate an LPB fifo READ transaction
+ * @data: location to copy data into
+ * @cs: LocalPlus bus chip select number for transfer
+ * @offset: Location of data to read as an offset from the CS base address
+ * @size: Size of transfer in bytes
+ * @callback: Callback function for FIFO events.  Will be called when the
+ *            FIFO high watermark is reached, when the transfer finishes,
+ *            and if a FIFO error occurs.
+ * @data: Private data pointer to be passed to callback function.
+ */
+int mpc52xx_lpbfifo_read(void *dest, unsigned int cs,
+			 size_t offset, size_t size, int mode_flags,
+			 void (*callback)(void *, size_t, int),
+			 void *callback_data)
+{
+	int rc = -EBUSY;
+	unsigned long flags;
+
+	if (!lpbfifo.regs)
+		return -ENODEV;
+
+	spin_lock_irqsave(&lpbfifo.lock, flags);
+	/* If the data pointer is already set then a transfer is in progress */
+	if (lpbfifo.data)
+		goto out;
+
+	/* Setup the transfer */
+	lpbfifo.data = dest;
+	lpbfifo.cs = cs;
+	lpbfifo.offset = offset;
+	lpbfifo.remaining = lpbfifo.size = size;
+	lpbfifo.callback = callback;
+	lpbfifo.callback_data = callback_data;
+
+	mpc52xx_lpbfifo_kick();
+	rc = 0;
+
+ out:
+	spin_unlock_irqrestore(&lpbfifo.lock, flags);
+	return rc;
+}
+EXPORT_SYMBOL(mpc52xx_lpbfifo_read);
+
+void mpc52xx_lpbfifo_abort(void *callback_data)
+{
+	unsigned long flags;
+
+	if (lpbfifo.callback_data != callback_data)
+		return;
+
+	spin_lock_irqsave(&lpbfifo.lock, flags);
+	/* Put it into reset and clear the state */
+	out_be32(lpbfifo.regs + LPBFIFO_REG_ENABLE, 0x01010000);
+	lpbfifo.data = NULL;
+	spin_unlock_irqrestore(&lpbfifo.lock, flags);
+}
+EXPORT_SYMBOL(mpc52xx_lpbfifo_abort);
+
+static int __devinit
+mpc52xx_lpbfifo_probe(struct of_device *op, const struct of_device_id *match)
+{
+	int rc;
+
+	if (lpbfifo.dev != NULL)
+		return -ENOSPC;
+
+	lpbfifo.regs = of_iomap(op->node, 0);
+	if (!lpbfifo.regs)
+		return -ENOMEM;
+
+	lpbfifo.irq = irq_of_parse_and_map(op->node, 0);
+	if (!lpbfifo.irq) {
+		lpbfifo.regs = NULL;
+		iounmap(lpbfifo.regs);
+		return -ENOMEM;
+	}
+
+	spin_lock_init(&lpbfifo.lock);
+
+	/* Put FIFO into reset */
+	out_be32(lpbfifo.regs + LPBFIFO_REG_ENABLE, 0x01010000);
+
+	/* Register the interrupt handler */
+	rc = request_irq(lpbfifo.irq, mpc52xx_lpbfifo_irq, 0,
+			 "mpc52xx-lpbfifo", &lpbfifo);
+	if (rc) {
+		pr_err("request_irq() failed.  rc=%i\n", rc);
+		lpbfifo.regs = NULL;
+		free_irq(lpbfifo.irq, &lpbfifo);
+		iounmap(lpbfifo.regs);
+	}
+
+	lpbfifo.dev = &op->dev;
+	pr_info("LPB FIFO ready; regs=%p irq=%i\n", lpbfifo.regs, lpbfifo.irq);
+	return 0;
+}
+
+
+static int __devexit mpc52xx_lpbfifo_remove(struct of_device *op)
+{
+	if (lpbfifo.dev == &op->dev) {
+		/* Put FIFO in reset */
+		out_be32(lpbfifo.regs + LPBFIFO_REG_ENABLE, 0x01010000);
+		lpbfifo.regs = NULL;
+		free_irq(lpbfifo.irq, &lpbfifo);
+		iounmap(lpbfifo.regs);
+		lpbfifo.dev = NULL;
+	}
+	return 0;
+}
+
+static struct of_device_id mpc52xx_lpbfifo_match[] __devinitdata = {
+	{ .compatible = "fsl,mpc5200-lpbfifo", },
+	{},
+};
+
+static struct of_platform_driver mpc52xx_lpbfifo_driver = {
+	.owner = THIS_MODULE,
+	.name = "mpc52xx-lpbfifo",
+	.match_table = mpc52xx_lpbfifo_match,
+	.probe = mpc52xx_lpbfifo_probe,
+	.remove = __devexit_p(mpc52xx_lpbfifo_remove),
+};
+
+/***********************************************************************
+ * Module init/exit
+ */
+static int __init mpc52xx_lpbfifo_init(void)
+{
+	pr_debug("Registering LocalPlus bus FIFO driver\n");
+	return of_register_platform_driver(&mpc52xx_lpbfifo_driver);
+}
+module_init(mpc52xx_lpbfifo_init);
+
+static void __exit mpc52xx_lpbfifo_exit(void)
+{
+	pr_debug("Unregistering LocalPlus bus FIFO driver\n");
+	of_unregister_platform_driver(&mpc52xx_lpbfifo_driver);
+}
+module_exit(mpc52xx_lpbfifo_exit);

Re: [RFC 1/2] powerpc/5200: add general purpose timer API for the MPC5200

[Jon Smirl]

[-- Attachment #1: Type: text/plain, Size: 748 bytes --]

I'm using a GPT pin in input capture mode to implement IR. I attached
my GPT driver code. I can convert to your API. That's a really cheap
way to do IR, just IR sensor, resistor and a cap.

I also have an in-kernel IR system but Christoph (lirc maintainer)
won't consider it. He is a microkernel type - he wants everything in
user space. My in-kernel version is tiny, less than 10K. It turns IR
events into keystrokes on a virtual keyboard device.

This is my old device tree, what should the new one look like?

		ir0@670 { /* General Purpose Timer 6 in Input mode */
			compatible = "gpt-ir";
			cell-index = <7>;
			reg = <0x670 0x10>;
			interrupts = <0x1 0x10 0x0>;
			interrupt-parent = <&mpc5200_pic>;
		};

-- 
Jon Smirl
jonsmirl@gmail.com

[-- Attachment #2: jds-lirc-gpt --]
[-- Type: application/octet-stream, Size: 5699 bytes --]

GPT driver for in-kernel IR support.

From: Jon Smirl <jonsmirl@gmail.com>

GPT is a GPIO pin that is cable able of measuring the lenght of pulses.
GPTs are common on embedded systems
---
 drivers/input/ir/Kconfig  |    6 +
 drivers/input/ir/Makefile |    3 +
 drivers/input/ir/ir-gpt.c |  184 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 193 insertions(+), 0 deletions(-)
 create mode 100644 drivers/input/ir/ir-gpt.c

diff --git a/drivers/input/ir/Kconfig b/drivers/input/ir/Kconfig
index a6f3f25..172c0c6 100644
--- a/drivers/input/ir/Kconfig
+++ b/drivers/input/ir/Kconfig
@@ -12,4 +12,10 @@ menuconfig INPUT_IR
 
 if INPUT_IR
 
+config IR_GPT
+	tristate "GPT Based IR Receiver"
+	default m
+	help
+	  Driver for GPT-based IR receiver found on Digispeaker
+
 endif
diff --git a/drivers/input/ir/Makefile b/drivers/input/ir/Makefile
index 2ccdda3..ab0da3f 100644
--- a/drivers/input/ir/Makefile
+++ b/drivers/input/ir/Makefile
@@ -6,3 +6,6 @@
 obj-$(CONFIG_INPUT_IR)		+= ir.o
 ir-objs := ir-core.o ir-configfs.o
 
+
+obj-$(CONFIG_IR_GPT)		+= ir-gpt.o
+
diff --git a/drivers/input/ir/ir-gpt.c b/drivers/input/ir/ir-gpt.c
new file mode 100644
index 0000000..41d2fa6
--- /dev/null
+++ b/drivers/input/ir/ir-gpt.c
@@ -0,0 +1,184 @@
+/*
+ * GPT timer based IR device
+ *
+ * Copyright (C) 2008 Jon Smirl <jonsmirl@gmail.com>
+ */
+
+#define DEBUG
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/device.h>
+#include <linux/of_device.h>
+#include <linux/of_platform.h>
+#include <linux/input.h>
+#include <asm/io.h>
+#include <asm/mpc52xx.h>
+
+struct ir_gpt {
+	struct input_dev *input;
+	int irq, previous;
+	struct mpc52xx_gpt __iomem *regs;
+};
+
+/*
+ * Interrupt handlers
+ */
+static irqreturn_t dpeak_ir_irq(int irq, void *_ir)
+{
+	struct ir_gpt *ir_gpt = _ir;
+	int sample, count, delta, bit, wrap;
+
+	sample = in_be32(&ir_gpt->regs->status);
+	out_be32(&ir_gpt->regs->status, 0xF);
+
+	count = sample >> 16;
+	wrap = (sample >> 12) & 7;
+	bit = (sample >> 8) & 1;
+
+	delta = count - ir_gpt->previous;
+	delta += wrap * 0x10000;
+
+	ir_gpt->previous = count;
+
+	if (bit)
+		delta = -delta;
+
+	input_ir_queue(ir_gpt->input, delta);
+
+	return IRQ_HANDLED;
+}
+
+
+/* ---------------------------------------------------------------------
+ * OF platform bus binding code:
+ * - Probe/remove operations
+ * - OF device match table
+ */
+static int __devinit ir_gpt_of_probe(struct of_device *op,
+				      const struct of_device_id *match)
+{
+	struct ir_gpt *ir_gpt;
+	struct resource res;
+	int ret, rc;
+
+	dev_dbg(&op->dev, "ir_gpt_of_probe\n");
+
+	/* Allocate and initialize the driver private data */
+	ir_gpt = kzalloc(sizeof *ir_gpt, GFP_KERNEL);
+	if (!ir_gpt)
+		return -ENOMEM;
+
+	ir_gpt->input = input_allocate_device();
+	if (!ir_gpt->input) {
+		ret = -ENOMEM;
+		goto free_mem;
+	}
+	ret = input_ir_create(ir_gpt->input, ir_gpt, NULL);
+	if (ret)
+		goto free_input;
+
+	ir_gpt->input->id.bustype = BUS_HOST;
+	ir_gpt->input->name = "GPT IR Receiver";
+
+	ir_gpt->input->irbit[0] |= BIT_MASK(IR_CAP_RECEIVE_36K);
+	ir_gpt->input->irbit[0] |= BIT_MASK(IR_CAP_RECEIVE_38K);
+	ir_gpt->input->irbit[0] |= BIT_MASK(IR_CAP_RECEIVE_40K);
+	ir_gpt->input->irbit[0] |= BIT_MASK(IR_CAP_RECEIVE_RAW);
+
+	ret = input_register_device(ir_gpt->input);
+	if (ret)
+		goto free_input;
+	ret = input_ir_register(ir_gpt->input);
+	if (ret)
+		goto free_input;
+
+	/* Fetch the registers and IRQ of the GPT */
+	if (of_address_to_resource(op->node, 0, &res)) {
+		dev_err(&op->dev, "Missing reg property\n");
+		ret = -ENODEV;
+		goto free_input;
+	}
+	ir_gpt->regs = ioremap(res.start, 1 + res.end - res.start);
+	if (!ir_gpt->regs) {
+		dev_err(&op->dev, "Could not map registers\n");
+		ret = -ENODEV;
+		goto free_input;
+	}
+	ir_gpt->irq = irq_of_parse_and_map(op->node, 0);
+	if (ir_gpt->irq == NO_IRQ) {
+		ret = -ENODEV;
+		goto free_input;
+	}
+	dev_dbg(&op->dev, "ir_gpt_of_probe irq=%d\n", ir_gpt->irq);
+
+	rc = request_irq(ir_gpt->irq, &dpeak_ir_irq, IRQF_SHARED,
+			 "gpt-ir", ir_gpt);
+	dev_dbg(&op->dev, "ir_gpt_of_probe request irq rc=%d\n", rc);
+
+	/* set prescale to ? */
+	out_be32(&ir_gpt->regs->count, 0x00870000);
+
+	/* Select input capture, enable the counter, and interrupt */
+	out_be32(&ir_gpt->regs->mode, 0x0);
+	out_be32(&ir_gpt->regs->mode, 0x00000501);
+
+	/* Save what we've done so it can be found again later */
+	dev_set_drvdata(&op->dev, ir_gpt);
+
+	printk("GPT IR Receiver driver\n");
+
+	return 0;
+
+free_input:
+	input_free_device(ir_gpt->input);
+free_mem:
+	kfree(ir_gpt);
+	return ret;
+}
+
+static int __devexit ir_gpt_of_remove(struct of_device *op)
+{
+	struct ir_gpt *ir_gpt = dev_get_drvdata(&op->dev);
+
+	dev_dbg(&op->dev, "ir_gpt_remove()\n");
+
+	input_unregister_device(ir_gpt->input);
+	kfree(ir_gpt);
+	dev_set_drvdata(&op->dev, NULL);
+
+	return 0;
+}
+
+/* Match table for of_platform binding */
+static struct of_device_id ir_gpt_match[] __devinitdata = {
+	{ .compatible = "gpt-ir", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, ir_gpt_match);
+
+static struct of_platform_driver ir_gpt_driver = {
+	.match_table = ir_gpt_match,
+	.probe = ir_gpt_of_probe,
+	.remove = __devexit_p(ir_gpt_of_remove),
+	.driver = {
+		.name = "ir-gpt",
+		.owner = THIS_MODULE,
+	},
+};
+
+/* ---------------------------------------------------------------------
+ * Module setup and teardown; simply register the of_platform driver
+ */
+static int __init ir_gpt_init(void)
+{
+	return of_register_platform_driver(&ir_gpt_driver);
+}
+module_init(ir_gpt_init);
+
+static void __exit ir_gpt_exit(void)
+{
+	of_unregister_platform_driver(&ir_gpt_driver);
+}
+module_exit(ir_gpt_exit);

Re: [RFC 1/2] powerpc/5200: add general purpose timer API for the MPC5200

[Grant Likely]

On Fri, Mar 6, 2009 at 2:29 PM, Jon Smirl <jonsmirl@gmail.com> wrote:
> I'm using a GPT pin in input capture mode to implement IR. I attached
> my GPT driver code. I can convert to your API. That's a really cheap
> way to do IR, just IR sensor, resistor and a cap.

The driver I posted can't do input capture mode yet, but it shouldn't
be too difficult to add.  Just another api function for setting the
mode I think.  I don't have a use for that yet, so I haven't thought
much about it.  Feel free to suggest what you think the API should
look like.

> This is my old device tree, what should the new one look like?
>
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0ir0@670 { /* General Purpose Timer 6 in In=
put mode */
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0compatible =3D "gpt-ir";
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0cell-index =3D <7>;
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0reg =3D <0x670 0x10>;
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0interrupts =3D <0x1 0x10 0=
x0>;
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0interrupt-parent =3D <&mpc=
5200_pic>;
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0};

You'd want a node for the IR device which uses the GPT node as its
interrupt controller.

so:
    gpt7: gpt@670 {
        compatible =3D "fsl,mpc5200b-gpt"
        reg =3D <0x670 0x10>;
        interrupt =3D <1 16 0>;
        interrupt-controller;
        #interrupt-cells =3D <1>;
    };

Then elsewhere:
    ir {
        compatible =3D "digispeaker,ir";  // or whatever best matches your =
board
        interrupt-parent =3D <&gpt>;
        interrupts =3D <0>;  // IIRC, '0' means irq on both edges for
the GPT irq controller
    };

g.

--=20
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.