cregit-Linux how code gets into the kernel

Release 4.14 arch/mips/alchemy/common/dma.c

/*
 *
 * BRIEF MODULE DESCRIPTION
 *      A DMA channel allocator for Au1x00. API is modeled loosely off of
 *      linux/kernel/dma.c.
 *
 * Copyright 2000, 2008 MontaVista Software Inc.
 * Author: MontaVista Software, Inc. <source@mvista.com>
 * Copyright (C) 2005 Ralf Baechle (ralf@linux-mips.org)
 *
 *  This program is free software; you can redistribute  it and/or modify it
 *  under  the terms of  the GNU General  Public License as published by the
 *  Free Software Foundation;  either version 2 of the  License, or (at your
 *  option) any later version.
 *
 *  THIS  SOFTWARE  IS PROVIDED   ``AS  IS'' AND   ANY  EXPRESS OR IMPLIED
 *  WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
 *  NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT, INDIRECT,
 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF
 *  USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT
 *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *  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.,
 *  675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

#include <linux/init.h>
#include <linux/export.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>

#include <asm/mach-au1x00/au1000.h>
#include <asm/mach-au1x00/au1000_dma.h>

/*
 * A note on resource allocation:
 *
 * All drivers needing DMA channels, should allocate and release them
 * through the public routines `request_dma()' and `free_dma()'.
 *
 * In order to avoid problems, all processes should allocate resources in
 * the same sequence and release them in the reverse order.
 *
 * So, when allocating DMAs and IRQs, first allocate the DMA, then the IRQ.
 * When releasing them, first release the IRQ, then release the DMA. The
 * main reason for this order is that, if you are requesting the DMA buffer
 * done interrupt, you won't know the irq number until the DMA channel is
 * returned from request_dma.
 */

/* DMA Channel register block spacing */

#define DMA_CHANNEL_LEN		0x00000100


DEFINE_SPINLOCK(au1000_dma_spin_lock);


struct dma_chan au1000_dma_table[NUM_AU1000_DMA_CHANNELS] = {
      {.dev_id = -1,},
      {.dev_id = -1,},
      {.dev_id = -1,},
      {.dev_id = -1,},
      {.dev_id = -1,},
      {.dev_id = -1,},
      {.dev_id = -1,},
      {.dev_id = -1,}
};

EXPORT_SYMBOL(au1000_dma_table);

/* Device FIFO addresses and default DMA modes */

static const struct dma_dev {
	
unsigned int fifo_addr;
	
unsigned int dma_mode;

} dma_dev_table[DMA_NUM_DEV] = {
	{ AU1000_UART0_PHYS_ADDR + 0x04, DMA_DW8 },		/* UART0_TX */
	{ AU1000_UART0_PHYS_ADDR + 0x00, DMA_DW8 | DMA_DR },	/* UART0_RX */
	{ 0, 0 },	/* DMA_REQ0 */
	{ 0, 0 },	/* DMA_REQ1 */
	{ AU1000_AC97_PHYS_ADDR + 0x08, DMA_DW16 },		/* AC97 TX c */
	{ AU1000_AC97_PHYS_ADDR + 0x08, DMA_DW16 | DMA_DR },	/* AC97 RX c */
	{ AU1000_UART3_PHYS_ADDR + 0x04, DMA_DW8 | DMA_NC },	/* UART3_TX */
	{ AU1000_UART3_PHYS_ADDR + 0x00, DMA_DW8 | DMA_NC | DMA_DR }, /* UART3_RX */
	{ AU1000_USB_UDC_PHYS_ADDR + 0x00, DMA_DW8 | DMA_NC | DMA_DR }, /* EP0RD */
	{ AU1000_USB_UDC_PHYS_ADDR + 0x04, DMA_DW8 | DMA_NC }, /* EP0WR */
	{ AU1000_USB_UDC_PHYS_ADDR + 0x08, DMA_DW8 | DMA_NC }, /* EP2WR */
	{ AU1000_USB_UDC_PHYS_ADDR + 0x0c, DMA_DW8 | DMA_NC }, /* EP3WR */
	{ AU1000_USB_UDC_PHYS_ADDR + 0x10, DMA_DW8 | DMA_NC | DMA_DR }, /* EP4RD */
	{ AU1000_USB_UDC_PHYS_ADDR + 0x14, DMA_DW8 | DMA_NC | DMA_DR }, /* EP5RD */
	/* on Au1500, these 2 are DMA_REQ2/3 (GPIO208/209) instead! */
	{ AU1000_I2S_PHYS_ADDR + 0x00, DMA_DW32 | DMA_NC},	/* I2S TX */
	{ AU1000_I2S_PHYS_ADDR + 0x00, DMA_DW32 | DMA_NC | DMA_DR}, /* I2S RX */
};


int au1000_dma_read_proc(char *buf, char **start, off_t fpos, int length, int *eof, void *data) { int i, len = 0; struct dma_chan *chan; for (i = 0; i < NUM_AU1000_DMA_CHANNELS; i++) { chan = get_dma_chan(i); if (chan != NULL) len += sprintf(buf + len, "%2d: %s\n", i, chan->dev_str); } if (fpos >= len) { *start = buf; *eof = 1; return 0; } *start = buf + fpos; len -= fpos; if (len > length) return length; *eof = 1; return len; }

Contributors

PersonTokensPropCommitsCommitProp
Ralf Bächle12694.03%150.00%
Sergei Shtylyov85.97%150.00%
Total134100.00%2100.00%

/* Device FIFO addresses and default DMA modes - 2nd bank */ static const struct dma_dev dma_dev_table_bank2[DMA_NUM_DEV_BANK2] = { { AU1100_SD0_PHYS_ADDR + 0x00, DMA_DS | DMA_DW8 }, /* coherent */ { AU1100_SD0_PHYS_ADDR + 0x04, DMA_DS | DMA_DW8 | DMA_DR }, /* coherent */ { AU1100_SD1_PHYS_ADDR + 0x00, DMA_DS | DMA_DW8 }, /* coherent */ { AU1100_SD1_PHYS_ADDR + 0x04, DMA_DS | DMA_DW8 | DMA_DR } /* coherent */ };
void dump_au1000_dma_channel(unsigned int dmanr) { struct dma_chan *chan; if (dmanr >= NUM_AU1000_DMA_CHANNELS) return; chan = &au1000_dma_table[dmanr]; printk(KERN_INFO "Au1000 DMA%d Register Dump:\n", dmanr); printk(KERN_INFO " mode = 0x%08x\n", __raw_readl(chan->io + DMA_MODE_SET)); printk(KERN_INFO " addr = 0x%08x\n", __raw_readl(chan->io + DMA_PERIPHERAL_ADDR)); printk(KERN_INFO " start0 = 0x%08x\n", __raw_readl(chan->io + DMA_BUFFER0_START)); printk(KERN_INFO " start1 = 0x%08x\n", __raw_readl(chan->io + DMA_BUFFER1_START)); printk(KERN_INFO " count0 = 0x%08x\n", __raw_readl(chan->io + DMA_BUFFER0_COUNT)); printk(KERN_INFO " count1 = 0x%08x\n", __raw_readl(chan->io + DMA_BUFFER1_COUNT)); }

Contributors

PersonTokensPropCommitsCommitProp
Ralf Bächle12094.49%133.33%
Manuel Lauss64.72%133.33%
Andrew Morton10.79%133.33%
Total127100.00%3100.00%

/* * Finds a free channel, and binds the requested device to it. * Returns the allocated channel number, or negative on error. * Requests the DMA done IRQ if irqhandler != NULL. */
int request_au1000_dma(int dev_id, const char *dev_str, irq_handler_t irqhandler, unsigned long irqflags, void *irq_dev_id) { struct dma_chan *chan; const struct dma_dev *dev; int i, ret; if (alchemy_get_cputype() == ALCHEMY_CPU_AU1100) { if (dev_id < 0 || dev_id >= (DMA_NUM_DEV + DMA_NUM_DEV_BANK2)) return -EINVAL; } else { if (dev_id < 0 || dev_id >= DMA_NUM_DEV) return -EINVAL; } for (i = 0; i < NUM_AU1000_DMA_CHANNELS; i++) if (au1000_dma_table[i].dev_id < 0) break; if (i == NUM_AU1000_DMA_CHANNELS) return -ENODEV; chan = &au1000_dma_table[i]; if (dev_id >= DMA_NUM_DEV) { dev_id -= DMA_NUM_DEV; dev = &dma_dev_table_bank2[dev_id]; } else dev = &dma_dev_table[dev_id]; if (irqhandler) { chan->irq_dev = irq_dev_id; ret = request_irq(chan->irq, irqhandler, irqflags, dev_str, chan->irq_dev); if (ret) { chan->irq_dev = NULL; return ret; } } else { chan->irq_dev = NULL; } /* fill it in */ chan->io = (void __iomem *)(KSEG1ADDR(AU1000_DMA_PHYS_ADDR) + i * DMA_CHANNEL_LEN); chan->dev_id = dev_id; chan->dev_str = dev_str; chan->fifo_addr = dev->fifo_addr; chan->mode = dev->dma_mode; /* initialize the channel before returning */ init_dma(i); return i; }

Contributors

PersonTokensPropCommitsCommitProp
Ralf Bächle18368.03%114.29%
Andrew Morton5721.19%114.29%
Manuel Lauss238.55%342.86%
Sergei Shtylyov51.86%114.29%
David Howells10.37%114.29%
Total269100.00%7100.00%

EXPORT_SYMBOL(request_au1000_dma);
void free_au1000_dma(unsigned int dmanr) { struct dma_chan *chan = get_dma_chan(dmanr); if (!chan) { printk(KERN_ERR "Error trying to free DMA%d\n", dmanr); return; } disable_dma(dmanr); if (chan->irq_dev) free_irq(chan->irq, chan->irq_dev); chan->irq_dev = NULL; chan->dev_id = -1; }

Contributors

PersonTokensPropCommitsCommitProp
Ralf Bächle6795.71%133.33%
Sergei Shtylyov22.86%133.33%
Manuel Lauss11.43%133.33%
Total70100.00%3100.00%

EXPORT_SYMBOL(free_au1000_dma);
static int __init au1000_dma_init(void) { int base, i; switch (alchemy_get_cputype()) { case ALCHEMY_CPU_AU1000: base = AU1000_DMA_INT_BASE; break; case ALCHEMY_CPU_AU1500: base = AU1500_DMA_INT_BASE; break; case ALCHEMY_CPU_AU1100: base = AU1100_DMA_INT_BASE; break; default: goto out; } for (i = 0; i < NUM_AU1000_DMA_CHANNELS; i++) au1000_dma_table[i].irq = base + i; printk(KERN_INFO "Alchemy DMA initialized\n"); out: return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Manuel Lauss84100.00%1100.00%
Total84100.00%1100.00%

arch_initcall(au1000_dma_init);

Overall Contributors

PersonTokensPropCommitsCommitProp
Ralf Bächle71466.60%321.43%
Manuel Lauss21520.06%535.71%
Andrew Morton11911.10%321.43%
Sergei Shtylyov222.05%17.14%
Paul Gortmaker10.09%17.14%
David Howells10.09%17.14%
Total1072100.00%14100.00%
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
Created with cregit.