* [PATCH 1/3 v2] [RESEND]spi: controller driver for Designware SPI core
@ 2009-09-21 8:47 Feng Tang
2009-09-29 22:16 ` Andrew Morton
0 siblings, 1 reply; 2+ messages in thread
From: Feng Tang @ 2009-09-21 8:47 UTC (permalink / raw)
To: dbrownell-Rn4VEauK+AKRv+LV9MX5uipxlwaOVQ5f,
spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f,
akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b
>From 5d87c87105aba522468cabb6fe206a4515dc85e8 Mon Sep 17 00:00:00 2001
From: Feng Tang <feng.tang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Date: Tue, 4 Aug 2009 16:23:47 +0800
Subject: [PATCH 1/3] spi: controller driver for Designware SPI core
Driver for the Designware SPI core, it supports multipul interfaces
like PCI/APB etc. User can use "dw_apb_ssi_db.pdf" from Synopsys as
HW datasheet.
Signed-off-by: Feng Tang <feng.tang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
---
drivers/spi/Kconfig | 6 +
drivers/spi/Makefile | 1 +
drivers/spi/dw_spi.c | 941 ++++++++++++++++++++++++++++++++++++++++++++
include/linux/spi/dw_spi.h | 212 ++++++++++
4 files changed, 1160 insertions(+), 0 deletions(-)
create mode 100644 drivers/spi/dw_spi.c
create mode 100644 include/linux/spi/dw_spi.h
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 2c733c2..80b1017 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -227,6 +227,12 @@ config SPI_XILINX
See the "OPB Serial Peripheral Interface (SPI) (v1.00e)"
Product Specification document (DS464) for hardware details.
+config SPI_DESIGNWARE
+ bool "DesignWare SPI controller core support"
+ depends on SPI_MASTER
+ help
+ general driver for SPI controller core from DesignWare
+
#
# Add new SPI master controllers in alphabetical order above this line
#
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 3de408d..f3f36e0 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -31,6 +31,7 @@ obj-$(CONFIG_SPI_S3C24XX) += spi_s3c24xx.o
obj-$(CONFIG_SPI_TXX9) += spi_txx9.o
obj-$(CONFIG_SPI_XILINX) += xilinx_spi.o
obj-$(CONFIG_SPI_SH_SCI) += spi_sh_sci.o
+obj-$(CONFIG_SPI_DESIGNWARE) += dw_spi.o
# ... add above this line ...
# SPI protocol drivers (device/link on bus)
diff --git a/drivers/spi/dw_spi.c b/drivers/spi/dw_spi.c
new file mode 100644
index 0000000..261c27c
--- /dev/null
+++ b/drivers/spi/dw_spi.c
@@ -0,0 +1,941 @@
+/*
+ * dw_spi.c - Designware SPI core controller driver (refer pxa2xx_spi.c)
+ *
+ * Copyright (c) 2009, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <linux/highmem.h>
+#include <linux/delay.h>
+
+#include <linux/spi/dw_spi.h>
+#include <linux/spi/spi.h>
+
+#ifdef CONFIG_DEBUG_FS
+#include <linux/debugfs.h>
+#endif
+
+#define START_STATE ((void *)0)
+#define RUNNING_STATE ((void *)1)
+#define DONE_STATE ((void *)2)
+#define ERROR_STATE ((void *)-1)
+
+#define QUEUE_RUNNING 0
+#define QUEUE_STOPPED 1
+
+#define MRST_SPI_DEASSERT 0
+#define MRST_SPI_ASSERT 1
+
+/* Slave spi_dev related */
+struct chip_data {
+ u16 cr0;
+ u8 cs; /* chip select pin */
+ u8 n_bytes; /* current is a 1/2/4 byte op */
+ u8 tmode; /* TR/TO/RO/EEPROM */
+ u8 type; /* SPI/SSP/MicroWire */
+
+ u8 poll_mode; /* 1 means use poll mode */
+
+ u32 dma_width;
+ u32 rx_threshold;
+ u32 tx_threshold;
+ u8 enable_dma;
+ u8 bits_per_word;
+ u16 clk_div; /* baud rate divider */
+ u32 speed_hz; /* baud rate */
+ int (*write)(struct dw_spi *dws);
+ int (*read)(struct dw_spi *dws);
+ void (*cs_control)(u32 command);
+};
+
+#ifdef CONFIG_DEBUG_FS
+static int spi_show_regs_open(struct inode *inode, struct file *file)
+{
+ file->private_data = inode->i_private;
+ return 0;
+}
+
+#define SPI_REGS_BUFSIZE 1024
+static ssize_t spi_show_regs(struct file *file, char __user *user_buf,
+ size_t count, loff_t *ppos)
+{
+ struct dw_spi *dws;
+ char *buf;
+ u32 len = 0;
+ ssize_t ret;
+
+ dws = (struct dw_spi *)file->private_data;
+
+ buf = kzalloc(SPI_REGS_BUFSIZE, GFP_KERNEL);
+ if (!buf)
+ return 0;
+
+ len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+ "MRST SPI0 registers:\n");
+ len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+ "=================================\n");
+ len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+ "CTRL0: \t\t0x%08x\n", dw_readl(dws, ctrl0));
+ len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+ "CTRL1: \t\t0x%08x\n", dw_readl(dws, ctrl1));
+ len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+ "SSIENR: \t0x%08x\n", dw_readl(dws, ssienr));
+ len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+ "SER: \t\t0x%08x\n", dw_readl(dws, ser));
+ len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+ "BAUDR: \t\t0x%08x\n", dw_readl(dws, baudr));
+ len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+ "TXFTLR: \t0x%08x\n", dw_readl(dws, txfltr));
+ len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+ "RXFTLR: \t0x%08x\n", dw_readl(dws, rxfltr));
+ len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+ "TXFLR: \t\t0x%08x\n", dw_readl(dws, txflr));
+ len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+ "RXFLR: \t\t0x%08x\n", dw_readl(dws, rxflr));
+ len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+ "SR: \t\t0x%08x\n", dw_readl(dws, sr));
+ len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+ "IMR: \t\t0x%08x\n", dw_readl(dws, imr));
+ len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+ "ISR: \t\t0x%08x\n", dw_readl(dws, isr));
+ len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+ "DMACR: \t\t0x%08x\n", dw_readl(dws, dmacr));
+ len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+ "DMATDLR: \t0x%08x\n", dw_readl(dws, dmatdlr));
+ len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+ "DMARDLR: \t0x%08x\n", dw_readl(dws, dmardlr));
+ len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+ "=================================\n");
+
+ ret = simple_read_from_buffer(user_buf, count, ppos, buf, len);
+ kfree(buf);
+ return ret;
+}
+
+static const struct file_operations mrst_spi_regs_ops = {
+ .owner = THIS_MODULE,
+ .open = spi_show_regs_open,
+ .read = spi_show_regs,
+};
+
+static int mrst_spi_debugfs_init(struct dw_spi *dws)
+{
+ dws->debugfs = debugfs_create_dir("mrst_spi", NULL);
+ if (!dws->debugfs)
+ return -ENOMEM;
+
+ debugfs_create_file("registers", S_IFREG | S_IRUGO,
+ dws->debugfs, (void *)dws, &mrst_spi_regs_ops);
+ return 0;
+}
+
+static void mrst_spi_debugfs_remove(struct dw_spi *dws)
+{
+ if (dws->debugfs)
+ debugfs_remove_recursive(dws->debugfs);
+}
+
+#else
+static inline int mrst_spi_debugfs_init(struct dw_spi *dws)
+{
+}
+
+static inline void mrst_spi_debugfs_remove(struct dw_spi *dws)
+{
+}
+#endif /* CONFIG_DEBUG_FS */
+
+static int flush(struct dw_spi *dws)
+{
+ unsigned long limit = loops_per_jiffy << 1;
+
+ while (dw_readw(dws, sr) & SR_RF_NOT_EMPT) {
+ limit = loops_per_jiffy << 1;
+ while ((dw_readw(dws, sr) & SR_BUSY) && limit--)
+ ;
+ dw_readw(dws, dr);
+ }
+ return limit;
+}
+
+static void null_cs_control(u32 command)
+{
+}
+
+static int null_writer(struct dw_spi *dws)
+{
+ u8 n_bytes = dws->n_bytes;
+
+ if (!(dw_readw(dws, sr) & SR_TF_NOT_FULL)
+ || (dws->tx == dws->tx_end))
+ return 0;
+ dw_writew(dws, dr, 0);
+ dws->tx += n_bytes;
+ return 1;
+}
+
+static int null_reader(struct dw_spi *dws)
+{
+ u8 n_bytes = dws->n_bytes;
+
+ while ((dw_readw(dws, sr) & SR_RF_NOT_EMPT)
+ && (dws->rx < dws->rx_end)) {
+ dw_readw(dws, dr);
+ dws->rx += n_bytes;
+ }
+ return dws->rx == dws->rx_end;
+}
+
+static int u8_writer(struct dw_spi *dws)
+{
+ if (!(dw_readw(dws, sr) & SR_TF_NOT_FULL)
+ || (dws->tx == dws->tx_end))
+ return 0;
+
+ dw_writew(dws, dr, *(u8 *)(dws->tx));
+ ++dws->tx;
+
+ while (dw_readw(dws, sr) & SR_BUSY)
+ ;
+ return 1;
+}
+
+static int u8_reader(struct dw_spi *dws)
+{
+ while ((dw_readw(dws, sr) & SR_RF_NOT_EMPT)
+ && (dws->rx < dws->rx_end)) {
+ *(u8 *)(dws->rx) = dw_readw(dws, dr);
+ ++dws->rx;
+ }
+
+ while (dw_readw(dws, sr) & SR_BUSY)
+ ;
+ return dws->rx == dws->rx_end;
+}
+
+static int u16_writer(struct dw_spi *dws)
+{
+ if (!(dw_readw(dws, sr) & SR_TF_NOT_FULL)
+ || (dws->tx == dws->tx_end))
+ return 0;
+
+ dw_writew(dws, dr, *(u16 *)(dws->tx));
+ dws->tx += 2;
+ while (dw_readw(dws, sr) & SR_BUSY)
+ ;
+
+ return 1;
+}
+
+static int u16_reader(struct dw_spi *dws)
+{
+ u16 temp;
+
+ while ((dw_readw(dws, sr) & SR_RF_NOT_EMPT)
+ && (dws->rx < dws->rx_end)) {
+ temp = dw_readw(dws, dr);
+ *(u16 *)(dws->rx) = temp;
+ dws->rx += 2;
+ }
+
+ while (dw_readw(dws, sr) & SR_BUSY)
+ ;
+
+ return dws->rx == dws->rx_end;
+}
+
+static void *next_transfer(struct dw_spi *dws)
+{
+ struct spi_message *msg = dws->cur_msg;
+ struct spi_transfer *trans = dws->cur_transfer;
+
+ /* Move to next transfer */
+ if (trans->transfer_list.next != &msg->transfers) {
+ dws->cur_transfer =
+ list_entry(trans->transfer_list.next,
+ struct spi_transfer,
+ transfer_list);
+ return RUNNING_STATE;
+ } else
+ return DONE_STATE;
+}
+
+/*
+ * Note: first step is the protocol driver prepares
+ * a dma-capable memory, and this func just need translate
+ * the virt addr to physical
+ */
+static int map_dma_buffers(struct dw_spi *dws)
+{
+ if (!dws->cur_msg->is_dma_mapped || !dws->dma_inited
+ || !dws->cur_chip->enable_dma)
+ return 0;
+
+ if (dws->cur_transfer->tx_dma)
+ dws->tx_dma = dws->cur_transfer->tx_dma;
+
+ if (dws->cur_transfer->rx_dma)
+ dws->rx_dma = dws->cur_transfer->rx_dma;
+
+ return 1;
+}
+
+static inline void unmap_dma_buffers(struct dw_spi *dws)
+{
+ if (!dws->dma_mapped)
+ return;
+ dws->dma_mapped = 0;
+}
+
+/* Caller already set message->status; dma and pio irqs are blocked */
+static void giveback(struct dw_spi *dws)
+{
+ struct spi_transfer *last_transfer;
+ unsigned long flags;
+ struct spi_message *msg;
+
+ spin_lock_irqsave(&dws->lock, flags);
+ msg = dws->cur_msg;
+ dws->cur_msg = NULL;
+ dws->cur_transfer = NULL;
+ dws->prev_chip = dws->cur_chip;
+ dws->cur_chip = NULL;
+ queue_work(dws->workqueue, &dws->pump_messages);
+ spin_unlock_irqrestore(&dws->lock, flags);
+
+ last_transfer = list_entry(msg->transfers.prev,
+ struct spi_transfer,
+ transfer_list);
+
+ if (!last_transfer->cs_change)
+ dws->cs_control(MRST_SPI_DEASSERT);
+
+ msg->state = NULL;
+ if (msg->complete)
+ msg->complete(msg->context);
+}
+
+static void int_error_stop(struct dw_spi *dws, const char *msg)
+{
+ /* Stop and reset hw */
+ flush(dws);
+ spi_enable_chip(dws, 0);
+
+ dev_err(&dws->master->dev, "%s\n", msg);
+ dws->cur_msg->state = ERROR_STATE;
+ tasklet_schedule(&dws->pump_transfers);
+}
+
+static void transfer_complete(struct dw_spi *dws)
+{
+ /* Update total byte transfered return count actual bytes read */
+ dws->cur_msg->actual_length += dws->len;
+
+ /* Move to next transfer */
+ dws->cur_msg->state = next_transfer(dws);
+
+ /* Handle end of message */
+ if (dws->cur_msg->state == DONE_STATE) {
+ dws->cur_msg->status = 0;
+ giveback(dws);
+ } else
+ tasklet_schedule(&dws->pump_transfers);
+}
+
+static irqreturn_t interrupt_transfer(struct dw_spi *dws)
+{
+ u16 irq_status, irq_mask = 0x3f;
+
+ irq_status = dw_readw(dws, isr) & irq_mask;
+ /* Error handling */
+ if (irq_status & (SPI_INT_TXOI | SPI_INT_RXOI | SPI_INT_RXUI)) {
+ dw_readw(dws, txoicr);
+ dw_readw(dws, rxoicr);
+ dw_readw(dws, rxuicr);
+ int_error_stop(dws, "interrupt_transfer: fifo overrun");
+ return IRQ_HANDLED;
+ }
+
+ /* INT comes from tx */
+ if (dws->tx && (irq_status & SPI_INT_TXEI))
+ while (dws->tx < dws->tx_end) {
+ dws->write(dws);
+
+ if (dws->tx == dws->tx_end) {
+ spi_mask_intr(dws, SPI_INT_TXEI);
+ transfer_complete(dws);
+ }
+ }
+
+ /* INT comes from rx */
+ if (dws->rx && (irq_status & SPI_INT_RXFI)) {
+ if (dws->read(dws))
+ transfer_complete(dws);
+ }
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t dw_spi_irq(int irq, void *dev_id)
+{
+ struct dw_spi *dws = dev_id;
+
+ if (!dws->cur_msg) {
+ spi_mask_intr(dws, SPI_INT_TXEI);
+ /* Never fail */
+ return IRQ_HANDLED;
+ }
+
+ return dws->transfer_handler(dws);
+}
+
+/* Must be called inside pump_transfers() */
+static void poll_transfer(struct dw_spi *dws)
+{
+ if (dws->tx)
+ while (dws->write(dws))
+ dws->read(dws);
+
+ dws->read(dws);
+ transfer_complete(dws);
+}
+
+static void dma_transfer(struct dw_spi *dws, int cs_change)
+{
+}
+
+static void pump_transfers(unsigned long data)
+{
+ struct dw_spi *dws = (struct dw_spi *)data;
+ struct spi_message *message = NULL;
+ struct spi_transfer *transfer = NULL;
+ struct spi_transfer *previous = NULL;
+ struct spi_device *spi = NULL;
+ struct chip_data *chip = NULL;
+ u8 bits = 0;
+ u8 imask = 0;
+ u8 cs_change = 0;
+ u16 clk_div = 0;
+ u32 speed = 0;
+ u32 cr0 = 0;
+
+ /* Get current state information */
+ message = dws->cur_msg;
+ transfer = dws->cur_transfer;
+ chip = dws->cur_chip;
+ spi = message->spi;
+
+ if (message->state == ERROR_STATE) {
+ message->status = -EIO;
+ goto early_exit;
+ }
+
+ /* Handle end of message */
+ if (message->state == DONE_STATE) {
+ message->status = 0;
+ goto early_exit;
+ }
+
+ /* Delay if requested at end of transfer*/
+ if (message->state == RUNNING_STATE) {
+ previous = list_entry(transfer->transfer_list.prev,
+ struct spi_transfer,
+ transfer_list);
+ if (previous->delay_usecs)
+ udelay(previous->delay_usecs);
+ }
+
+ dws->n_bytes = chip->n_bytes;
+ dws->dma_width = chip->dma_width;
+ dws->cs_control = chip->cs_control;
+
+ dws->rx_dma = transfer->rx_dma;
+ dws->tx_dma = transfer->tx_dma;
+ dws->tx = (void *)transfer->tx_buf;
+ dws->tx_end = dws->tx + transfer->len;
+ dws->rx = transfer->rx_buf;
+ dws->rx_end = dws->rx + transfer->len;
+ dws->write = dws->tx ? chip->write : null_writer;
+ dws->read = dws->rx ? chip->read : null_reader;
+ dws->cs_change = transfer->cs_change;
+ dws->len = dws->cur_transfer->len;
+ if (chip != dws->prev_chip)
+ cs_change = 1;
+
+ cr0 = chip->cr0;
+
+ /* Handle per transfer options for bpw and speed */
+ if (transfer->speed_hz) {
+ speed = chip->speed_hz;
+
+ if (transfer->speed_hz != speed) {
+ speed = transfer->speed_hz;
+ if (speed > dws->max_freq) {
+ printk(KERN_ERR "MRST SPI0: unsupported"
+ "freq: %dHz\n", speed);
+ message->status = -EIO;
+ goto early_exit;
+ }
+
+ /* clk_div doesn't support odd number */
+ clk_div = dws->max_freq / speed;
+ clk_div = (clk_div >> 1) << 1;
+
+ chip->speed_hz = speed;
+ chip->clk_div = clk_div;
+ }
+ }
+ if (transfer->bits_per_word) {
+ bits = transfer->bits_per_word;
+
+ switch (bits) {
+ case 8:
+ dws->n_bytes = 1;
+ dws->dma_width = 1;
+ dws->read = (dws->read != null_reader) ?
+ u8_reader : null_reader;
+ dws->write = (dws->write != null_writer) ?
+ u8_writer : null_writer;
+ break;
+ case 16:
+ dws->n_bytes = 2;
+ dws->dma_width = 2;
+ dws->read = (dws->read != null_reader) ?
+ u16_reader : null_reader;
+ dws->write = (dws->write != null_writer) ?
+ u16_writer : null_writer;
+ break;
+ default:
+ printk(KERN_ERR "MRST SPI0: unsupported bits:"
+ "%db\n", bits);
+ message->status = -EIO;
+ goto early_exit;
+ }
+
+ cr0 = (bits - 1)
+ | (chip->type << SPI_FRF_OFFSET)
+ | (spi->mode << SPI_MODE_OFFSET)
+ | (chip->tmode << SPI_TMOD_OFFSET);
+ }
+ message->state = RUNNING_STATE;
+
+ /* Try to map dma buffer and do a dma transfer if successful */
+ dws->dma_mapped = map_dma_buffers(dws);
+
+ if (!dws->dma_mapped && !chip->poll_mode) {
+ if (dws->rx)
+ imask |= SPI_INT_RXFI;
+ if (dws->tx)
+ imask |= SPI_INT_TXEI;
+ dws->transfer_handler = interrupt_transfer;
+ }
+
+ /*
+ * Reprogram registers only if
+ * 1. chip select changes
+ * 2. clk_div is changed
+ * 3. control value changes
+ */
+ if (dw_readw(dws, ctrl0) != cr0 || cs_change || clk_div) {
+ spi_enable_chip(dws, 0);
+
+ if (dw_readw(dws, ctrl0) != cr0)
+ dw_writew(dws, ctrl0, cr0);
+
+ /* Set the interrupt mask, for poll mode just diable all int */
+ spi_mask_intr(dws, 0xff);
+ if (!chip->poll_mode)
+ spi_umask_intr(dws, imask);
+
+ spi_set_clk(dws, clk_div ? clk_div : chip->clk_div);
+ spi_chip_sel(dws, spi->chip_select);
+ spi_enable_chip(dws, 1);
+
+ if (cs_change)
+ dws->prev_chip = chip;
+ }
+
+ if (dws->dma_mapped)
+ dma_transfer(dws, cs_change);
+
+ if (chip->poll_mode)
+ poll_transfer(dws);
+
+ return;
+
+early_exit:
+ giveback(dws);
+ return;
+}
+
+static void pump_messages(struct work_struct *work)
+{
+ struct dw_spi *dws =
+ container_of(work, struct dw_spi, pump_messages);
+ unsigned long flags;
+
+ /* Lock queue and check for queue work */
+ spin_lock_irqsave(&dws->lock, flags);
+ if (list_empty(&dws->queue) || dws->run == QUEUE_STOPPED) {
+ dws->busy = 0;
+ spin_unlock_irqrestore(&dws->lock, flags);
+ return;
+ }
+
+ /* Make sure we are not already running a message */
+ if (dws->cur_msg) {
+ spin_unlock_irqrestore(&dws->lock, flags);
+ return;
+ }
+
+ /* Extract head of queue */
+ dws->cur_msg = list_entry(dws->queue.next, struct spi_message, queue);
+ list_del_init(&dws->cur_msg->queue);
+
+ /* Initial message state*/
+ dws->cur_msg->state = START_STATE;
+ dws->cur_transfer = list_entry(dws->cur_msg->transfers.next,
+ struct spi_transfer,
+ transfer_list);
+ dws->cur_chip = spi_get_ctldata(dws->cur_msg->spi);
+
+ /* Mark as busy and launch transfers */
+ tasklet_schedule(&dws->pump_transfers);
+
+ dws->busy = 1;
+ spin_unlock_irqrestore(&dws->lock, flags);
+}
+
+/* spi_device use this to queue in their spi_msg */
+static int dw_spi_transfer(struct spi_device *spi, struct spi_message *msg)
+{
+ struct dw_spi *dws = spi_master_get_devdata(spi->master);
+ unsigned long flags;
+
+ spin_lock_irqsave(&dws->lock, flags);
+
+ if (dws->run == QUEUE_STOPPED) {
+ spin_unlock_irqrestore(&dws->lock, flags);
+ return -ESHUTDOWN;
+ }
+
+ msg->actual_length = 0;
+ msg->status = -EINPROGRESS;
+ msg->state = START_STATE;
+
+ list_add_tail(&msg->queue, &dws->queue);
+
+ if (dws->run == QUEUE_RUNNING && !dws->busy) {
+
+ if (dws->cur_transfer || dws->cur_msg)
+ queue_work(dws->workqueue,
+ &dws->pump_messages);
+ else {
+ /* If no other data transaction in air, just go */
+ spin_unlock_irqrestore(&dws->lock, flags);
+ pump_messages(&dws->pump_messages);
+ return 0;
+ }
+ }
+
+ spin_unlock_irqrestore(&dws->lock, flags);
+ return 0;
+}
+
+/* This may be called twice for each spi dev */
+static int dw_spi_setup(struct spi_device *spi)
+{
+ struct dw_spi_chip *chip_info = NULL;
+ struct chip_data *chip;
+
+ if (spi->bits_per_word != 8 && spi->bits_per_word != 16)
+ return -EINVAL;
+
+ /* Only alloc on first setup */
+ chip = spi_get_ctldata(spi);
+ if (!chip) {
+ chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
+ if (!chip)
+ return -ENOMEM;
+
+ chip->cs_control = null_cs_control;
+ chip->enable_dma = 0;
+ }
+
+ /*
+ * Protocol drivers may change the chip settings, so...
+ * if chip_info exists, use it
+ */
+ chip_info = spi->controller_data;
+
+ /* chip_info doesn't always exist */
+ if (chip_info) {
+ if (chip_info->cs_control)
+ chip->cs_control = chip_info->cs_control;
+
+ chip->poll_mode = chip_info->poll_mode;
+ chip->type = chip_info->type;
+
+ chip->rx_threshold = 0;
+ chip->tx_threshold = 0;
+
+ chip->enable_dma = chip_info->enable_dma;
+ }
+
+ if (spi->bits_per_word <= 8) {
+ chip->n_bytes = 1;
+ chip->dma_width = 1;
+ chip->read = u8_reader;
+ chip->write = u8_writer;
+ } else if (spi->bits_per_word <= 16) {
+ chip->n_bytes = 2;
+ chip->dma_width = 2;
+ chip->read = u16_reader;
+ chip->write = u16_writer;
+ } else {
+ /* Never take >16b case for MRST SPIC */
+ dev_err(&spi->dev, "invalid wordsize\n");
+ return -EINVAL;
+ }
+ chip->bits_per_word = spi->bits_per_word;
+
+ chip->speed_hz = spi->max_speed_hz;
+ if (chip->speed_hz)
+ chip->clk_div = 25000000 / chip->speed_hz;
+ else
+ chip->clk_div = 8; /* default value */
+
+ chip->tmode = 0; /* Tx & Rx */
+ /* Default SPI mode is SCPOL = 0, SCPH = 0 */
+ chip->cr0 = (chip->bits_per_word - 1)
+ | (chip->type << SPI_FRF_OFFSET)
+ | (spi->mode << SPI_MODE_OFFSET)
+ | (chip->tmode << SPI_TMOD_OFFSET);
+
+ spi_set_ctldata(spi, chip);
+ return 0;
+}
+
+static void dw_spi_cleanup(struct spi_device *spi)
+{
+ struct chip_data *chip = spi_get_ctldata(spi);
+ kfree(chip);
+}
+
+static int __init init_queue(struct dw_spi *dws)
+{
+ INIT_LIST_HEAD(&dws->queue);
+ spin_lock_init(&dws->lock);
+
+ dws->run = QUEUE_STOPPED;
+ dws->busy = 0;
+
+ tasklet_init(&dws->pump_transfers,
+ pump_transfers, (unsigned long)dws);
+
+ INIT_WORK(&dws->pump_messages, pump_messages);
+ dws->workqueue = create_singlethread_workqueue(
+ dev_name(dws->master->dev.parent));
+ if (dws->workqueue == NULL)
+ return -EBUSY;
+
+ return 0;
+}
+
+static int start_queue(struct dw_spi *dws)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&dws->lock, flags);
+
+ if (dws->run == QUEUE_RUNNING || dws->busy) {
+ spin_unlock_irqrestore(&dws->lock, flags);
+ return -EBUSY;
+ }
+
+ dws->run = QUEUE_RUNNING;
+ dws->cur_msg = NULL;
+ dws->cur_transfer = NULL;
+ dws->cur_chip = NULL;
+ dws->prev_chip = NULL;
+ spin_unlock_irqrestore(&dws->lock, flags);
+
+ queue_work(dws->workqueue, &dws->pump_messages);
+
+ return 0;
+}
+
+static int stop_queue(struct dw_spi *dws)
+{
+ unsigned long flags;
+ unsigned limit = 500;
+ int status = 0;
+
+ spin_lock_irqsave(&dws->lock, flags);
+ dws->run = QUEUE_STOPPED;
+ while (!list_empty(&dws->queue) && dws->busy && limit--) {
+ spin_unlock_irqrestore(&dws->lock, flags);
+ msleep(10);
+ spin_lock_irqsave(&dws->lock, flags);
+ }
+
+ if (!list_empty(&dws->queue) || dws->busy)
+ status = -EBUSY;
+ spin_unlock_irqrestore(&dws->lock, flags);
+
+ return status;
+}
+
+static int destroy_queue(struct dw_spi *dws)
+{
+ int status;
+
+ status = stop_queue(dws);
+ if (status != 0)
+ return status;
+ destroy_workqueue(dws->workqueue);
+ return 0;
+}
+
+/* Restart the controller, disable all interrupts, clean rx fifo */
+static void spi_hw_init(struct dw_spi *dws)
+{
+ spi_enable_chip(dws, 0);
+ spi_mask_intr(dws, 0xff);
+ spi_enable_chip(dws, 1);
+ flush(dws);
+}
+
+int __devinit dw_spi_add_host(struct dw_spi *dws)
+{
+ struct spi_master *master;
+ int ret;
+
+ BUG_ON(dws == NULL);
+
+ master = spi_alloc_master(dws->parent_dev, 0);
+ if (!master) {
+ ret = -ENOMEM;
+ goto exit;
+ }
+
+ dws->master = master;
+ dws->type = SSI_MOTO_SPI;
+ dws->prev_chip = NULL;
+ dws->dma_inited = 0;
+ dws->dma_addr = (dma_addr_t)(dws->paddr + 0x60);
+
+ ret = request_irq(dws->irq, dw_spi_irq, 0,
+ "dw_spi", dws);
+ if (ret < 0) {
+ dev_err(&master->dev, "can not get IRQ\n");
+ goto err_free_master;
+ }
+
+ master->mode_bits = SPI_CPOL | SPI_CPHA;
+ master->bus_num = dws->bus_num;
+ master->num_chipselect = dws->num_cs;
+ master->cleanup = dw_spi_cleanup;
+ master->setup = dw_spi_setup;
+ master->transfer = dw_spi_transfer;
+
+ dws->dma_inited = 0;
+
+ /* Basic HW init */
+ spi_hw_init(dws);
+
+ /* Initial and start queue */
+ ret = init_queue(dws);
+ if (ret) {
+ dev_err(&master->dev, "problem initializing queue\n");
+ goto err_diable_hw;
+ }
+ ret = start_queue(dws);
+ if (ret) {
+ dev_err(&master->dev, "problem starting queue\n");
+ goto err_diable_hw;
+ }
+
+ spi_master_set_devdata(master, dws);
+ ret = spi_register_master(master);
+ if (ret) {
+ dev_err(&master->dev, "problem registering spi master\n");
+ goto err_queue_alloc;
+ }
+
+ mrst_spi_debugfs_init(dws);
+ return 0;
+
+err_queue_alloc:
+ destroy_queue(dws);
+err_diable_hw:
+ spi_enable_chip(dws, 0);
+ free_irq(dws->irq, dws);
+err_free_master:
+ spi_master_put(master);
+exit:
+ return ret;
+}
+
+void __devexit dw_spi_remove_host(struct dw_spi *dws)
+{
+ int status = 0;
+
+ if (!dws)
+ return;
+ mrst_spi_debugfs_remove(dws);
+
+ /* Remove the queue */
+ status = destroy_queue(dws);
+ if (status != 0)
+ dev_err(&dws->master->dev, "dw_spi_remove: workqueue will not "
+ "complete, message memory not freed\n");
+
+ spi_enable_chip(dws, 0);
+ /* Disable clk */
+ spi_set_clk(dws, 0);
+ free_irq(dws->irq, dws);
+
+ /* Disconnect from the SPI framework */
+ spi_unregister_master(dws->master);
+}
+
+int dw_spi_suspend_host(struct dw_spi *dws)
+{
+ int ret = 0;
+
+ ret = stop_queue(dws);
+ if (ret)
+ return ret;
+ spi_enable_chip(dws, 0);
+ spi_set_clk(dws, 0);
+ return ret;
+}
+
+int dw_spi_resume_host(struct dw_spi *dws)
+{
+ int ret;
+
+ spi_hw_init(dws);
+ ret = start_queue(dws);
+ if (ret)
+ dev_err(&dws->master->dev, "fail to start queue (%d)\n", ret);
+ return ret;
+}
+
+MODULE_AUTHOR("Feng Tang <feng.tang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>");
+MODULE_DESCRIPTION("Driver for DesignWare SPI controller core");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/spi/dw_spi.h b/include/linux/spi/dw_spi.h
new file mode 100644
index 0000000..51b3e77
--- /dev/null
+++ b/include/linux/spi/dw_spi.h
@@ -0,0 +1,212 @@
+#ifndef DW_SPI_HEADER_H
+#define DW_SPI_HEADER_H
+#include <linux/io.h>
+
+/* Bit fields in CTRLR0 */
+#define SPI_DFS_OFFSET 0
+
+#define SPI_FRF_OFFSET 4
+#define SPI_FRF_SPI 0x0
+#define SPI_FRF_SSP 0x1
+#define SPI_FRF_MICROWIRE 0x2
+#define SPI_FRF_RESV 0x3
+
+#define SPI_MODE_OFFSET 6
+#define SPI_SCPH_OFFSET 6
+#define SPI_SCOL_OFFSET 7
+#define SPI_TMOD_OFFSET 8
+#define SPI_TMOD_TR 0x0 /* xmit & recv */
+#define SPI_TMOD_TO 0x1 /* xmit only */
+#define SPI_TMOD_RO 0x2 /* recv only */
+#define SPI_TMOD_EPROMREAD 0x3 /* eeprom read mode */
+
+#define SPI_SLVOE_OFFSET 10
+#define SPI_SRL_OFFSET 11
+#define SPI_CFS_OFFSET 12
+
+/* Bit fields in SR, 7 bits */
+#define SR_MASK 0x7f /* cover 7 bits */
+#define SR_BUSY (1 << 0)
+#define SR_TF_NOT_FULL (1 << 1)
+#define SR_TF_EMPT (1 << 2)
+#define SR_RF_NOT_EMPT (1 << 3)
+#define SR_RF_FULL (1 << 4)
+#define SR_TX_ERR (1 << 5)
+#define SR_DCOL (1 << 6)
+
+/* Bit fields in ISR, IMR, RISR, 7 bits */
+#define SPI_INT_TXEI (1 << 0)
+#define SPI_INT_TXOI (1 << 1)
+#define SPI_INT_RXUI (1 << 2)
+#define SPI_INT_RXOI (1 << 3)
+#define SPI_INT_RXFI (1 << 4)
+#define SPI_INT_MSTI (1 << 5)
+
+/* TX RX interrupt level threshhold, max can be 256 */
+#define SPI_INT_THRESHOLD 32
+
+enum dw_ssi_type {
+ SSI_MOTO_SPI = 0,
+ SSI_TI_SSP,
+ SSI_NS_MICROWIRE,
+};
+
+struct dw_spi_reg {
+ u32 ctrl0;
+ u32 ctrl1;
+ u32 ssienr;
+ u32 mwcr;
+ u32 ser;
+ u32 baudr;
+ u32 txfltr;
+ u32 rxfltr;
+ u32 txflr;
+ u32 rxflr;
+ u32 sr;
+ u32 imr;
+ u32 isr;
+ u32 risr;
+ u32 txoicr;
+ u32 rxoicr;
+ u32 rxuicr;
+ u32 msticr;
+ u32 icr;
+ u32 dmacr;
+ u32 dmatdlr;
+ u32 dmardlr;
+ u32 idr;
+ u32 version;
+ u32 dr; /* Currently oper as 32 bits,
+ though only low 16 bits matters */
+} __packed;
+
+struct dw_spi {
+ struct spi_master *master;
+ struct spi_device *cur_dev;
+ struct device *parent_dev;
+ enum dw_ssi_type type;
+
+ void __iomem *regs;
+ unsigned long paddr;
+ u32 iolen;
+ int irq;
+ u32 max_freq; /* max bus freq supported */
+
+ u16 bus_num;
+ u16 num_cs; /* supported slave numbers */
+
+ /* Driver message queue */
+ struct workqueue_struct *workqueue;
+ struct work_struct pump_messages;
+ spinlock_t lock;
+ struct list_head queue;
+ int busy;
+ int run;
+
+ /* Message Transfer pump */
+ struct tasklet_struct pump_transfers;
+
+ /* Current message transfer state info */
+ struct spi_message *cur_msg;
+ struct spi_transfer *cur_transfer;
+ struct chip_data *cur_chip;
+ struct chip_data *prev_chip;
+ size_t len;
+ void *tx;
+ void *tx_end;
+ void *rx;
+ void *rx_end;
+ int dma_mapped;
+ dma_addr_t rx_dma;
+ dma_addr_t tx_dma;
+ size_t rx_map_len;
+ size_t tx_map_len;
+ u8 n_bytes; /* current is a 1/2 bytes op */
+ u8 max_bits_per_word; /* maxim is 16b */
+ u32 dma_width;
+ int cs_change;
+ int (*write)(struct dw_spi *dws);
+ int (*read)(struct dw_spi *dws);
+ irqreturn_t (*transfer_handler)(struct dw_spi *dws);
+ void (*cs_control)(u32 command);
+
+ /* Dma info */
+ int dma_inited;
+ struct dma_chan *txchan;
+ struct dma_chan *rxchan;
+ int txdma_done;
+ int rxdma_done;
+ u64 tx_param;
+ u64 rx_param;
+ struct device *dma_dev;
+ dma_addr_t dma_addr;
+
+ /* Bus interface info */
+ void *priv;
+#ifdef CONFIG_DEBUG_FS
+ struct dentry *debugfs;
+#endif
+};
+
+#define dw_readl(dw, name) \
+ __raw_readl(&(((struct dw_spi_reg *)dw->regs)->name))
+#define dw_writel(dw, name, val) \
+ __raw_writel((val), &(((struct dw_spi_reg *)dw->regs)->name))
+#define dw_readw(dw, name) \
+ __raw_readw(&(((struct dw_spi_reg *)dw->regs)->name))
+#define dw_writew(dw, name, val) \
+ __raw_writew((val), &(((struct dw_spi_reg *)dw->regs)->name))
+
+static inline void spi_enable_chip(struct dw_spi *dws, int enable)
+{
+ dw_writel(dws, ssienr, (enable ? 1 : 0));
+}
+
+static inline void spi_set_clk(struct dw_spi *dws, u16 div)
+{
+ dw_writel(dws, baudr, div);
+}
+
+static inline void spi_chip_sel(struct dw_spi *dws, u16 cs)
+{
+ if (cs > dws->num_cs)
+ return;
+ dw_writel(dws, ser, 1 << cs);
+}
+
+/* Disable IRQ bits */
+static inline void spi_mask_intr(struct dw_spi *dws, u32 mask)
+{
+ u32 new_mask;
+
+ new_mask = dw_readl(dws, imr) & ~mask;
+ dw_writel(dws, imr, new_mask);
+}
+
+/* Enable IRQ bits */
+static inline void spi_umask_intr(struct dw_spi *dws, u32 mask)
+{
+ u32 new_mask;
+
+ new_mask = dw_readl(dws, imr) | mask;
+ dw_writel(dws, imr, new_mask);
+}
+
+/*
+ * Each SPI slave device to work with dw_api controller should
+ * has such a structure claiming its working mode (PIO/DMA etc),
+ * which can be save in the "controller_data" member of the
+ * struct spi_device
+ */
+struct dw_spi_chip {
+ u8 poll_mode; /* 0 for contoller polling mode */
+ u8 type; /* SPI/SSP/Micrwire */
+ u8 enable_dma;
+ void (*cs_control)(u32 command);
+};
+
+extern int dw_spi_add_host(struct dw_spi *dws);
+extern void dw_spi_remove_host(struct dw_spi *dws);
+extern int dw_spi_suspend_host(struct dw_spi *dws);
+extern int dw_spi_resume_host(struct dw_spi *dws);
+#endif /* DW_SPI_HEADER_H */
--
1.5.6.3
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^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH 1/3 v2] [RESEND]spi: controller driver for Designware SPI core
2009-09-21 8:47 [PATCH 1/3 v2] [RESEND]spi: controller driver for Designware SPI core Feng Tang
@ 2009-09-29 22:16 ` Andrew Morton
0 siblings, 0 replies; 2+ messages in thread
From: Andrew Morton @ 2009-09-29 22:16 UTC (permalink / raw)
To: Feng Tang
Cc: spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f,
dbrownell-Rn4VEauK+AKRv+LV9MX5uipxlwaOVQ5f
On Mon, 21 Sep 2009 16:47:29 +0800
Feng Tang <feng.tang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> wrote:
> >From 5d87c87105aba522468cabb6fe206a4515dc85e8 Mon Sep 17 00:00:00 2001
> From: Feng Tang <feng.tang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> Date: Tue, 4 Aug 2009 16:23:47 +0800
> Subject: [PATCH 1/3] spi: controller driver for Designware SPI core
>
> Driver for the Designware SPI core, it supports multipul interfaces
> like PCI/APB etc. User can use "dw_apb_ssi_db.pdf" from Synopsys as
> HW datasheet.
It appears that your email client replaced all the tabs with spaces - I
cannot apply these patches.
>
> ...
>
> +#define SPI_REGS_BUFSIZE 1024
> +static ssize_t spi_show_regs(struct file *file, char __user *user_buf,
> + size_t count, loff_t *ppos)
> +{
> + struct dw_spi *dws;
> + char *buf;
> + u32 len = 0;
> + ssize_t ret;
> +
> + dws = (struct dw_spi *)file->private_data;
Unneeded and undesirable cast of void*.
> + buf = kzalloc(SPI_REGS_BUFSIZE, GFP_KERNEL);
> + if (!buf)
> + return 0;
> +
> + len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
> + "MRST SPI0 registers:\n");
> + len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
> + "=================================\n");
> + len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
> + "CTRL0: \t\t0x%08x\n", dw_readl(dws, ctrl0));
> + len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
> + "CTRL1: \t\t0x%08x\n", dw_readl(dws, ctrl1));
> + len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
> + "SSIENR: \t0x%08x\n", dw_readl(dws, ssienr));
> + len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
> + "SER: \t\t0x%08x\n", dw_readl(dws, ser));
> + len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
> + "BAUDR: \t\t0x%08x\n", dw_readl(dws, baudr));
> + len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
> + "TXFTLR: \t0x%08x\n", dw_readl(dws, txfltr));
> + len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
> + "RXFTLR: \t0x%08x\n", dw_readl(dws, rxfltr));
> + len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
> + "TXFLR: \t\t0x%08x\n", dw_readl(dws, txflr));
> + len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
> + "RXFLR: \t\t0x%08x\n", dw_readl(dws, rxflr));
> + len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
> + "SR: \t\t0x%08x\n", dw_readl(dws, sr));
> + len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
> + "IMR: \t\t0x%08x\n", dw_readl(dws, imr));
> + len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
> + "ISR: \t\t0x%08x\n", dw_readl(dws, isr));
> + len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
> + "DMACR: \t\t0x%08x\n", dw_readl(dws, dmacr));
> + len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
> + "DMATDLR: \t0x%08x\n", dw_readl(dws, dmatdlr));
> + len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
> + "DMARDLR: \t0x%08x\n", dw_readl(dws, dmardlr));
> + len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
> + "=================================\n");
> +
> + ret = simple_read_from_buffer(user_buf, count, ppos, buf, len);
> + kfree(buf);
> + return ret;
> +}
> +
>
> ...
>
> +static int flush(struct dw_spi *dws)
> +{
> + unsigned long limit = loops_per_jiffy << 1;
> +
> + while (dw_readw(dws, sr) & SR_RF_NOT_EMPT) {
> + limit = loops_per_jiffy << 1;
> + while ((dw_readw(dws, sr) & SR_BUSY) && limit--)
> + ;
> + dw_readw(dws, dr);
> + }
> + return limit;
> +}
The duration of this timeout will have little relation to jiffies or
anything like that. It'll mainly be dependent upon bus latencies. You
may find that the upper bound to this delay is very large indeed.
If you really did intend to set some upper bound on the polling period,
it'd be better to do
unsigned long end = jiffies + usecs_to_jiffies(1000);
while (time_before(jiffies, end)) {
...
}
or something along those lines.
>
> ...
>
> +static int u16_reader(struct dw_spi *dws)
> +{
> + u16 temp;
> +
> + while ((dw_readw(dws, sr) & SR_RF_NOT_EMPT)
> + && (dws->rx < dws->rx_end)) {
> + temp = dw_readw(dws, dr);
> + *(u16 *)(dws->rx) = temp;
> + dws->rx += 2;
> + }
> +
> + while (dw_readw(dws, sr) & SR_BUSY)
> + ;
The code does this a lot.
It's a bit of a worry - if the hardware is misbehaving or gets
hot-unplugged or powered off or such, the kernel will silently lock up.
Better practice would be to pull this into a separate function and to
at least emit a printk from that function when the hardware has locked
up. Even better, handle that error and recover.
> + return dws->rx == dws->rx_end;
> +}
> +
>
> ...
>
> +static inline void unmap_dma_buffers(struct dw_spi *dws)
> +{
> + if (!dws->dma_mapped)
> + return;
> + dws->dma_mapped = 0;
> +}
One would think that a function called unmap_dma_buffers() would unmap
dma buffers. But this doesn't do that.
>
> ...
>
------------------------------------------------------------------------------
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2009-09-21 8:47 [PATCH 1/3 v2] [RESEND]spi: controller driver for Designware SPI core Feng Tang
2009-09-29 22:16 ` Andrew Morton
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