[PATCH v3 1/3] powerpc/512x: add LocalPlus Bus FIFO device driver
Alexander Popov
alex.popov at linux.com
Fri Sep 25 03:28:55 AEST 2015
This driver for Freescale MPC512x LocalPlus Bus FIFO (called SCLPC
in the Reference Manual) allows Direct Memory Access transfers
between RAM and peripheral devices on LocalPlus Bus.
Signed-off-by: Alexander Popov <alex.popov at linux.com>
---
arch/powerpc/configs/mpc512x_defconfig | 1 +
arch/powerpc/include/asm/mpc5121.h | 59 +++
arch/powerpc/platforms/512x/Kconfig | 6 +
arch/powerpc/platforms/512x/Makefile | 1 +
arch/powerpc/platforms/512x/mpc512x_lpbfifo.c | 560 ++++++++++++++++++++++++++
5 files changed, 627 insertions(+)
create mode 100644 arch/powerpc/platforms/512x/mpc512x_lpbfifo.c
diff --git a/arch/powerpc/configs/mpc512x_defconfig b/arch/powerpc/configs/mpc512x_defconfig
index 59b85cb..d16d6c5 100644
--- a/arch/powerpc/configs/mpc512x_defconfig
+++ b/arch/powerpc/configs/mpc512x_defconfig
@@ -112,6 +112,7 @@ CONFIG_RTC_DRV_M41T80=y
CONFIG_RTC_DRV_MPC5121=y
CONFIG_DMADEVICES=y
CONFIG_MPC512X_DMA=y
+CONFIG_MPC512x_LPBFIFO=y
CONFIG_EXT2_FS=y
CONFIG_EXT2_FS_XIP=y
CONFIG_EXT3_FS=y
diff --git a/arch/powerpc/include/asm/mpc5121.h b/arch/powerpc/include/asm/mpc5121.h
index 4a69cd1..a6e8225 100644
--- a/arch/powerpc/include/asm/mpc5121.h
+++ b/arch/powerpc/include/asm/mpc5121.h
@@ -60,4 +60,63 @@ struct mpc512x_lpc {
int mpc512x_cs_config(unsigned int cs, u32 val);
+/*
+ * SCLPC Module (LPB FIFO)
+ */
+struct mpc512x_lpbfifo {
+ u32 pkt_size; /* SCLPC Packet Size Register */
+ u32 start_addr; /* SCLPC Start Address Register */
+ u32 ctrl; /* SCLPC Control Register */
+ u32 enable; /* SCLPC Enable Register */
+ u32 reserved1;
+ u32 status; /* SCLPC Status Register */
+ u32 bytes_done; /* SCLPC Bytes Done Register */
+ u32 emb_sc; /* EMB Share Counter Register */
+ u32 emb_pc; /* EMB Pause Control Register */
+ u32 reserved2[7];
+ u32 data_word; /* LPC RX/TX FIFO Data Word Register */
+ u32 fifo_status; /* LPC RX/TX FIFO Status Register */
+ u32 fifo_ctrl; /* LPC RX/TX FIFO Control Register */
+ u32 fifo_alarm; /* LPC RX/TX FIFO Alarm Register */
+};
+
+#define MPC512X_SCLPC_START (1 << 31)
+#define MPC512X_SCLPC_CS(x) (((x) & 0x7) << 24)
+#define MPC512X_SCLPC_FLUSH (1 << 17)
+#define MPC512X_SCLPC_READ (1 << 16)
+#define MPC512X_SCLPC_DAI (1 << 8)
+#define MPC512X_SCLPC_BPT(x) ((x) & 0x3f)
+#define MPC512X_SCLPC_RESET (1 << 24)
+#define MPC512X_SCLPC_FIFO_RESET (1 << 16)
+#define MPC512X_SCLPC_ABORT_INT_ENABLE (1 << 9)
+#define MPC512X_SCLPC_NORM_INT_ENABLE (1 << 8)
+#define MPC512X_SCLPC_ENABLE (1 << 0)
+#define MPC512X_SCLPC_SUCCESS (1 << 24)
+#define MPC512X_SCLPC_FIFO_CTRL(x) (((x) & 0x7) << 24)
+#define MPC512X_SCLPC_FIFO_ALARM(x) ((x) & 0x3ff)
+
+enum lpb_dev_portsize {
+ LPB_DEV_PORTSIZE_UNDEFINED = 0,
+ LPB_DEV_PORTSIZE_1_BYTE = 1,
+ LPB_DEV_PORTSIZE_2_BYTES = 2,
+ LPB_DEV_PORTSIZE_4_BYTES = 4,
+ LPB_DEV_PORTSIZE_8_BYTES = 8
+};
+
+enum mpc512x_lpbfifo_req_dir {
+ MPC512X_LPBFIFO_REQ_DIR_READ,
+ MPC512X_LPBFIFO_REQ_DIR_WRITE
+};
+
+struct mpc512x_lpbfifo_request {
+ phys_addr_t bus_phys; /* physical address of some device on LPB */
+ void *ram_virt; /* virtual address of some region in RAM */
+ u32 size;
+ enum lpb_dev_portsize portsize;
+ enum mpc512x_lpbfifo_req_dir dir;
+ void (*callback)(struct mpc512x_lpbfifo_request *);
+};
+
+int mpc512x_lpbfifo_submit(struct mpc512x_lpbfifo_request *req);
+
#endif /* __ASM_POWERPC_MPC5121_H__ */
diff --git a/arch/powerpc/platforms/512x/Kconfig b/arch/powerpc/platforms/512x/Kconfig
index 48bf38d..f09016f 100644
--- a/arch/powerpc/platforms/512x/Kconfig
+++ b/arch/powerpc/platforms/512x/Kconfig
@@ -10,6 +10,12 @@ config PPC_MPC512x
select USB_EHCI_BIG_ENDIAN_MMIO if USB_EHCI_HCD
select USB_EHCI_BIG_ENDIAN_DESC if USB_EHCI_HCD
+config MPC512x_LPBFIFO
+ tristate "MPC512x LocalPlus Bus FIFO driver"
+ depends on PPC_MPC512x && MPC512X_DMA
+ help
+ Enable support for Freescale MPC512x LocalPlus Bus FIFO (SCLPC).
+
config MPC5121_ADS
bool "Freescale MPC5121E ADS"
depends on PPC_MPC512x
diff --git a/arch/powerpc/platforms/512x/Makefile b/arch/powerpc/platforms/512x/Makefile
index 0169312..f47d422 100644
--- a/arch/powerpc/platforms/512x/Makefile
+++ b/arch/powerpc/platforms/512x/Makefile
@@ -5,4 +5,5 @@ obj-$(CONFIG_COMMON_CLK) += clock-commonclk.o
obj-y += mpc512x_shared.o
obj-$(CONFIG_MPC5121_ADS) += mpc5121_ads.o mpc5121_ads_cpld.o
obj-$(CONFIG_MPC512x_GENERIC) += mpc512x_generic.o
+obj-$(CONFIG_MPC512x_LPBFIFO) += mpc512x_lpbfifo.o
obj-$(CONFIG_PDM360NG) += pdm360ng.o
diff --git a/arch/powerpc/platforms/512x/mpc512x_lpbfifo.c b/arch/powerpc/platforms/512x/mpc512x_lpbfifo.c
new file mode 100644
index 0000000..e6f2c6b
--- /dev/null
+++ b/arch/powerpc/platforms/512x/mpc512x_lpbfifo.c
@@ -0,0 +1,560 @@
+/*
+ * The driver for Freescale MPC512x LocalPlus Bus FIFO
+ * (called SCLPC in the Reference Manual).
+ *
+ * Copyright (C) 2013-2015 Alexander Popov <alex.popov at linux.com>.
+ *
+ * This file is released under the GPLv2.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <asm/mpc5121.h>
+#include <asm/io.h>
+#include <linux/spinlock.h>
+#include <linux/slab.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-direction.h>
+#include <linux/dma-mapping.h>
+
+#define DRV_NAME "mpc512x_lpbfifo"
+
+struct cs_range {
+ u32 csnum;
+ u32 base; /* must be zero */
+ u32 addr;
+ u32 size;
+};
+
+static struct lpbfifo_data {
+ spinlock_t lock; /* for protecting lpbfifo_data */
+ phys_addr_t regs_phys;
+ resource_size_t regs_size;
+ struct mpc512x_lpbfifo __iomem *regs;
+ int irq;
+ struct cs_range *cs_ranges;
+ size_t cs_n;
+ struct dma_chan *chan;
+ struct mpc512x_lpbfifo_request *req;
+ dma_addr_t ram_bus_addr;
+ bool wait_lpbfifo_irq;
+ bool wait_lpbfifo_callback;
+} lpbfifo;
+
+/*
+ * A data transfer from RAM to some device on LPB is finished
+ * when both mpc512x_lpbfifo_irq() and mpc512x_lpbfifo_callback()
+ * have been called. We execute the callback registered in
+ * mpc512x_lpbfifo_request just after that.
+ * But for a data transfer from some device on LPB to RAM we don't enable
+ * LPBFIFO interrupt because clearing MPC512X_SCLPC_SUCCESS interrupt flag
+ * automatically disables LPBFIFO reading request to the DMA controller
+ * and the data transfer hangs. So the callback registered in
+ * mpc512x_lpbfifo_request is executed at the end of mpc512x_lpbfifo_callback().
+ */
+
+/*
+ * mpc512x_lpbfifo_irq - IRQ handler for LPB FIFO
+ */
+static irqreturn_t mpc512x_lpbfifo_irq(int irq, void *param)
+{
+ struct device *d = (struct device *)param;
+ struct mpc512x_lpbfifo_request *req = lpbfifo.req;
+ unsigned long flags;
+ u32 status;
+
+ spin_lock_irqsave(&lpbfifo.lock, flags);
+
+ if (!lpbfifo.regs)
+ goto end0;
+
+ if (!req || req->dir == MPC512X_LPBFIFO_REQ_DIR_READ) {
+ dev_err(d, "bogus LPBFIFO IRQ\n");
+ goto end0;
+ }
+
+ status = in_be32(&lpbfifo.regs->status);
+ if (status != MPC512X_SCLPC_SUCCESS) {
+ dev_err(d, "DMA transfer between RAM and peripheral failed\n");
+ out_be32(&lpbfifo.regs->enable,
+ MPC512X_SCLPC_RESET | MPC512X_SCLPC_FIFO_RESET);
+ goto end0;
+ }
+ /* Clear the interrupt flag */
+ out_be32(&lpbfifo.regs->status, MPC512X_SCLPC_SUCCESS);
+
+ lpbfifo.wait_lpbfifo_irq = false;
+
+ if (lpbfifo.wait_lpbfifo_callback)
+ goto end0;
+
+ /* Transfer is finished, set the FIFO as idle */
+ lpbfifo.req = NULL;
+
+ spin_unlock_irqrestore(&lpbfifo.lock, flags);
+
+ if (req->callback)
+ req->callback(req);
+
+ return IRQ_HANDLED;
+
+ end0:
+ spin_unlock_irqrestore(&lpbfifo.lock, flags);
+ return IRQ_HANDLED;
+}
+
+/*
+ * mpc512x_lpbfifo_callback is called by DMA driver when
+ * DMA transaction is finished.
+ */
+static void mpc512x_lpbfifo_callback(void *param)
+{
+ unsigned long flags;
+ struct mpc512x_lpbfifo_request *req = lpbfifo.req;
+ enum dma_data_direction dir;
+
+ spin_lock_irqsave(&lpbfifo.lock, flags);
+
+ if (!lpbfifo.regs) {
+ spin_unlock_irqrestore(&lpbfifo.lock, flags);
+ return;
+ }
+
+ if (!req) {
+ pr_err("bogus LPBFIFO callback\n");
+ spin_unlock_irqrestore(&lpbfifo.lock, flags);
+ return;
+ }
+
+ /* Release the mapping */
+ if (req->dir == MPC512X_LPBFIFO_REQ_DIR_WRITE)
+ dir = DMA_TO_DEVICE;
+ else
+ dir = DMA_FROM_DEVICE;
+ dma_unmap_single(lpbfifo.chan->device->dev,
+ lpbfifo.ram_bus_addr, req->size, dir);
+
+ lpbfifo.wait_lpbfifo_callback = false;
+
+ if (!lpbfifo.wait_lpbfifo_irq) {
+ /* Transfer is finished, set the FIFO as idle */
+ lpbfifo.req = NULL;
+
+ spin_unlock_irqrestore(&lpbfifo.lock, flags);
+
+ if (req->callback)
+ req->callback(req);
+ } else {
+ spin_unlock_irqrestore(&lpbfifo.lock, flags);
+ }
+}
+
+static int mpc512x_lpbfifo_kick(void)
+{
+ u32 bits;
+ int no_incr = 0;
+ u32 bpt;
+ u32 cs = 0;
+ size_t i;
+ struct dma_device *dma_dev = NULL;
+ struct scatterlist sg;
+ enum dma_data_direction dir;
+ struct dma_slave_config dma_conf = {};
+ struct dma_async_tx_descriptor *dma_tx = NULL;
+ dma_cookie_t cookie;
+ int e;
+
+ /*
+ * 1. Fit the requirements:
+ * - the packet size must be a multiple of 4 since FIFO Data Word
+ * Register allows only full-word access according the Reference
+ * Manual;
+ * - the physical address of the device on LPB and the packet size
+ * must be aligned on BPT (bytes per transaction) or 8-bytes
+ * boundary according the Reference Manual;
+ * - but we choose DMA maxburst equal (or very close to) BPT to prevent
+ * DMA controller from overtaking FIFO and causing FIFO underflow
+ * error. So we force the packet size to be aligned on BPT boundary
+ * not to confuse DMA driver which requires the packet size to be
+ * aligned on maxburst boundary;
+ * - BPT should be set to the LPB device port size for operation with
+ * disabled auto-incrementing according Reference Manual.
+ */
+ if (lpbfifo.req->size == 0 || !IS_ALIGNED(lpbfifo.req->size, 4)) {
+ e = -EINVAL;
+ goto err_param;
+ }
+
+ if (lpbfifo.req->portsize != LPB_DEV_PORTSIZE_UNDEFINED) {
+ bpt = lpbfifo.req->portsize;
+ no_incr = 1;
+ } else {
+ bpt = 32;
+ }
+ while (true) {
+ if (!IS_ALIGNED(lpbfifo.req->bus_phys, min(bpt, 0x8u)) ||
+ !IS_ALIGNED(lpbfifo.req->size, bpt)) {
+ if (no_incr) {
+ e = -EINVAL;
+ goto err_param;
+ }
+
+ bpt >>= 1;
+ } else {
+ dma_conf.dst_maxburst = max(bpt, 0x4u) / 4;
+ dma_conf.src_maxburst = max(bpt, 0x4u) / 4;
+ break;
+ }
+ }
+
+ for (i = 0; i < lpbfifo.cs_n; i++) {
+ phys_addr_t cs_start;
+ phys_addr_t cs_end;
+
+ cs_start = lpbfifo.cs_ranges[i].addr;
+ cs_end = cs_start + lpbfifo.cs_ranges[i].size - 1;
+
+ if (lpbfifo.req->bus_phys >= cs_start &&
+ lpbfifo.req->bus_phys + lpbfifo.req->size - 1 <= cs_end) {
+ cs = lpbfifo.cs_ranges[i].csnum;
+ break;
+ }
+ }
+ if (i == lpbfifo.cs_n) {
+ e = -EFAULT;
+ goto err_param;
+ }
+
+ /* 2. Prepare DMA */
+ dma_dev = lpbfifo.chan->device;
+
+ sg_init_table(&sg, 1);
+ if (lpbfifo.req->dir == MPC512X_LPBFIFO_REQ_DIR_WRITE)
+ dir = DMA_TO_DEVICE;
+ else
+ dir = DMA_FROM_DEVICE;
+ sg_dma_address(&sg) = dma_map_single(dma_dev->dev,
+ lpbfifo.req->ram_virt, lpbfifo.req->size, dir);
+ if (dma_mapping_error(dma_dev->dev, sg_dma_address(&sg))) {
+ e = -EFAULT;
+ goto err_param;
+ }
+ lpbfifo.ram_bus_addr = sg_dma_address(&sg); /* For freeing later */
+ sg_dma_len(&sg) = lpbfifo.req->size;
+
+ if (lpbfifo.req->dir == MPC512X_LPBFIFO_REQ_DIR_WRITE) {
+ dma_conf.direction = DMA_MEM_TO_DEV;
+ dma_conf.dst_addr = lpbfifo.regs_phys +
+ offsetof(struct mpc512x_lpbfifo, data_word);
+ } else {
+ dma_conf.direction = DMA_DEV_TO_MEM;
+ dma_conf.src_addr = lpbfifo.regs_phys +
+ offsetof(struct mpc512x_lpbfifo, data_word);
+ }
+ dma_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+ dma_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+
+ /* Make DMA channel work with LPB FIFO data register */
+ if (dma_dev->device_config(lpbfifo.chan, &dma_conf)) {
+ e = -EINVAL;
+ goto err_dma_prep;
+ }
+
+ dma_tx = dmaengine_prep_slave_sg(lpbfifo.chan, &sg,
+ 1, dma_conf.direction, 0);
+ if (!dma_tx) {
+ e = -ENOSPC;
+ goto err_dma_prep;
+ }
+ dma_tx->callback = mpc512x_lpbfifo_callback;
+ dma_tx->callback_param = NULL;
+
+ /* 3. Prepare FIFO */
+ out_be32(&lpbfifo.regs->enable,
+ MPC512X_SCLPC_RESET | MPC512X_SCLPC_FIFO_RESET);
+ out_be32(&lpbfifo.regs->enable, 0x0);
+
+ /*
+ * Configure the watermarks for write operation (RAM->DMA->FIFO->dev):
+ * - high watermark 7 words according the Reference Manual,
+ * - low watermark 512 bytes (half of the FIFO).
+ * These watermarks don't work for read operation since the
+ * MPC512X_SCLPC_FLUSH bit is set (according the Reference Manual).
+ */
+ out_be32(&lpbfifo.regs->fifo_ctrl, MPC512X_SCLPC_FIFO_CTRL(0x7));
+ out_be32(&lpbfifo.regs->fifo_alarm, MPC512X_SCLPC_FIFO_ALARM(0x200));
+
+ /*
+ * Start address is a physical address of the region which belongs
+ * to the device on the LocalPlus Bus
+ */
+ out_be32(&lpbfifo.regs->start_addr, lpbfifo.req->bus_phys);
+
+ /*
+ * Configure chip select, transfer direction, address increment option
+ * and bytes per transaction option
+ */
+ bits = 0;
+ bits |= MPC512X_SCLPC_CS(cs);
+ if (lpbfifo.req->dir == MPC512X_LPBFIFO_REQ_DIR_READ)
+ bits |= MPC512X_SCLPC_READ | MPC512X_SCLPC_FLUSH;
+ if (no_incr)
+ bits |= MPC512X_SCLPC_DAI;
+ bits |= MPC512X_SCLPC_BPT(bpt);
+ out_be32(&lpbfifo.regs->ctrl, bits);
+
+ /* Unmask irqs */
+ bits = MPC512X_SCLPC_ENABLE | MPC512X_SCLPC_ABORT_INT_ENABLE;
+ if (lpbfifo.req->dir == MPC512X_LPBFIFO_REQ_DIR_WRITE)
+ bits |= MPC512X_SCLPC_NORM_INT_ENABLE;
+ else
+ lpbfifo.wait_lpbfifo_irq = false;
+
+ out_be32(&lpbfifo.regs->enable, bits);
+
+ /* 4. Set packet size and kick FIFO off */
+ bits = lpbfifo.req->size;
+ bits |= MPC512X_SCLPC_START;
+ out_be32(&lpbfifo.regs->pkt_size, bits);
+
+ /* 5. Finally kick DMA off */
+ cookie = dma_tx->tx_submit(dma_tx);
+ if (dma_submit_error(cookie)) {
+ e = -ENOSPC;
+ goto err_dma_submit;
+ }
+
+ return 0;
+
+ err_dma_submit:
+ out_be32(&lpbfifo.regs->enable,
+ MPC512X_SCLPC_RESET | MPC512X_SCLPC_FIFO_RESET);
+ err_dma_prep:
+ dma_unmap_single(dma_dev->dev, sg_dma_address(&sg),
+ lpbfifo.req->size, dir);
+ err_param:
+ return e;
+}
+
+int mpc512x_lpbfifo_submit(struct mpc512x_lpbfifo_request *req)
+{
+ unsigned long flags;
+ int result = 0;
+
+ spin_lock_irqsave(&lpbfifo.lock, flags);
+
+ if (!lpbfifo.regs) {
+ result = -ENODEV;
+ goto end0;
+ }
+
+ /* Check whether a transfer is in progress */
+ if (lpbfifo.req) {
+ result = -EBUSY;
+ goto end0;
+ }
+
+ lpbfifo.wait_lpbfifo_irq = true;
+ lpbfifo.wait_lpbfifo_callback = true;
+ lpbfifo.req = req;
+ result = mpc512x_lpbfifo_kick();
+ if (result != 0)
+ lpbfifo.req = NULL; /* Set the FIFO as idle */
+
+ end0:
+ spin_unlock_irqrestore(&lpbfifo.lock, flags);
+ return result;
+}
+EXPORT_SYMBOL(mpc512x_lpbfifo_submit);
+
+static int get_cs_ranges(void)
+{
+ int res = -ENODEV;
+ struct device_node *lb_node;
+ const u32 *addr_cells_p;
+ const u32 *size_cells_p;
+ int proplen;
+ size_t i;
+
+ lb_node = of_find_node_by_path("/localbus at 80000020");
+ if (!lb_node)
+ goto end0;
+
+ if (!of_device_is_compatible(lb_node, "fsl,mpc5121-localbus"))
+ goto end1;
+
+ /*
+ * The node defined as compatible with 'fsl,mpc5121-localbus'
+ * should have 2 address cells and 1 size cell.
+ * One item of its ranges property should consist of:
+ * - the first address cell which is the chipselect number;
+ * - the second address cell which is the offset in the chipselect,
+ * must be zero.
+ * - CPU address of the beginning of an access window;
+ * - the only size cell which is the size of an access window.
+ */
+ addr_cells_p = of_get_property(lb_node, "#address-cells", NULL);
+ size_cells_p = of_get_property(lb_node, "#size-cells", NULL);
+ if (addr_cells_p == NULL || *addr_cells_p != 2 ||
+ size_cells_p == NULL || *size_cells_p != 1) {
+ goto end1;
+ }
+
+ proplen = of_property_count_u32_elems(lb_node, "ranges");
+ if (proplen < 0 || proplen % 4 != 0)
+ goto end1;
+
+ lpbfifo.cs_n = proplen / 4;
+ lpbfifo.cs_ranges = kcalloc(lpbfifo.cs_n, sizeof(struct cs_range),
+ GFP_KERNEL);
+ if (!lpbfifo.cs_ranges)
+ goto end1;
+
+ if (of_property_read_u32_array(lb_node, "ranges",
+ (u32 *)lpbfifo.cs_ranges, proplen) != 0) {
+ goto end2;
+ }
+
+ for (i = 0; i < lpbfifo.cs_n; i++) {
+ if (lpbfifo.cs_ranges[i].base != 0)
+ goto end2;
+ }
+
+ res = 0;
+ end2:
+ if (res != 0)
+ kfree(lpbfifo.cs_ranges);
+ end1:
+ of_node_put(lb_node);
+ end0:
+ return res;
+}
+
+static int mpc512x_lpbfifo_probe(struct platform_device *pdev)
+{
+ struct resource r;
+ int e = 0;
+
+ memset(&lpbfifo, 0, sizeof(struct lpbfifo_data));
+
+ lpbfifo.irq = irq_of_parse_and_map(pdev->dev.of_node, 0);
+ if (lpbfifo.irq == NO_IRQ) {
+ dev_err(&pdev->dev, "mapping irq failed\n");
+ e = -ENODEV;
+ goto err0;
+ }
+
+ if (of_address_to_resource(pdev->dev.of_node, 0, &r) != 0) {
+ dev_err(&pdev->dev, "bad 'reg' in 'sclpc' device tree node\n");
+ e = -ENODEV;
+ goto err1;
+ }
+ lpbfifo.regs_phys = r.start;
+ lpbfifo.regs_size = resource_size(&r);
+
+ if (!request_mem_region(lpbfifo.regs_phys,
+ lpbfifo.regs_size, DRV_NAME)) {
+ dev_err(&pdev->dev, "unable to request region\n");
+ e = -EBUSY;
+ goto err1;
+ }
+
+ lpbfifo.regs = ioremap(lpbfifo.regs_phys, lpbfifo.regs_size);
+ if (!lpbfifo.regs) {
+ dev_err(&pdev->dev, "mapping registers failed\n");
+ e = -ENOMEM;
+ goto err2;
+ }
+
+ out_be32(&lpbfifo.regs->enable,
+ MPC512X_SCLPC_RESET | MPC512X_SCLPC_FIFO_RESET);
+
+ if (request_irq(lpbfifo.irq, mpc512x_lpbfifo_irq, 0,
+ DRV_NAME, &pdev->dev) != 0) {
+ dev_err(&pdev->dev, "requesting irq failed\n");
+ e = -ENODEV;
+ goto err3;
+ }
+
+ lpbfifo.chan = dma_request_slave_channel(&pdev->dev, "rx-tx");
+ if (lpbfifo.chan == NULL) {
+ dev_err(&pdev->dev, "requesting DMA channel failed\n");
+ e = -ENODEV;
+ goto err4;
+ }
+
+ if (get_cs_ranges() != 0) {
+ dev_err(&pdev->dev, "bad '/localbus' device tree node\n");
+ e = -ENODEV;
+ goto err5;
+ }
+
+ spin_lock_init(&lpbfifo.lock);
+
+ dev_info(&pdev->dev, "probe succeeded\n");
+ return 0;
+
+ err5:
+ dma_release_channel(lpbfifo.chan);
+ err4:
+ free_irq(lpbfifo.irq, &lpbfifo);
+ err3:
+ iounmap(lpbfifo.regs);
+ lpbfifo.regs = NULL;
+ err2:
+ release_mem_region(lpbfifo.regs_phys, lpbfifo.regs_size);
+ err1:
+ irq_dispose_mapping(lpbfifo.irq);
+ err0:
+ dev_err(&pdev->dev, "probe failed\n");
+ return e;
+}
+
+static int mpc512x_lpbfifo_remove(struct platform_device *pdev)
+{
+ unsigned long flags;
+ struct dma_device *dma_dev = lpbfifo.chan->device;
+ struct mpc512x_lpbfifo __iomem *regs = NULL;
+
+ spin_lock_irqsave(&lpbfifo.lock, flags);
+ regs = lpbfifo.regs;
+ lpbfifo.regs = NULL;
+ spin_unlock_irqrestore(&lpbfifo.lock, flags);
+
+ dma_dev->device_terminate_all(lpbfifo.chan);
+ out_be32(®s->enable, MPC512X_SCLPC_RESET | MPC512X_SCLPC_FIFO_RESET);
+ kfree(lpbfifo.cs_ranges);
+ dma_release_channel(lpbfifo.chan);
+ free_irq(lpbfifo.irq, &pdev->dev);
+ iounmap(regs);
+ release_mem_region(lpbfifo.regs_phys, lpbfifo.regs_size);
+ irq_dispose_mapping(lpbfifo.irq);
+
+ return 0;
+}
+
+static const struct of_device_id mpc512x_lpbfifo_match[] = {
+ { .compatible = "fsl,mpc512x-lpbfifo", },
+ {},
+};
+
+static struct platform_driver mpc512x_lpbfifo_driver = {
+ .probe = mpc512x_lpbfifo_probe,
+ .remove = mpc512x_lpbfifo_remove,
+ .driver = {
+ .name = DRV_NAME,
+ .owner = THIS_MODULE,
+ .of_match_table = mpc512x_lpbfifo_match,
+ },
+};
+
+module_platform_driver(mpc512x_lpbfifo_driver);
+
+MODULE_AUTHOR("Alexander Popov <alex.popov at linux.com>");
+MODULE_DESCRIPTION("MPC512x LocalPlus Bus FIFO device driver");
+MODULE_LICENSE("GPL v2");
--
1.9.1
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