From: Grant Likely <grant.lik...@secretlab.ca>
This is a driver for the LocalPlus bus FIFO device
Signed-off-by: Grant Likely <grant.lik...@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.lik...@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);
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