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linux/arch/arm/mach-omap2/dma.c
Nishanth Menon 76be4a5415 ARM: OMAP2+: DMA: remove requirement of irq for platform-dma driver 
we have currently 2 DMA drivers that try to co-exist.
drivers/dma/omap-dma.c which registers it's own IRQ and is device tree
aware and uses arch/arm/plat-omap/dma.c instance created by
arch/arm/mach-omap2/dma.c to maintain channel usage (omap_request_dma).

Currently both try to register interrupts and mach-omap2/plat-omap dma.c
attempts to use the IRQ number registered by hwmod to register it's own
interrupt handler.

Now, there is no reasonable way of static allocating DMA irq in GIC
SPI when we use crossbar. However, since the dma_chan structure is
freed as a result of IRQ not being present due to devm allocation,
maintaining information of channel by platform code fails at a later
point in time when that region of memory is reused.

So, if hwmod does not indicate an IRQ number, then, assume that
dma-engine will take care of the interrupt handling.

Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2014-07-21 23:32:51 -07:00

294 lines
8.8 KiB
C
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/*
* OMAP2+ DMA driver
*
* Copyright (C) 2003 - 2008 Nokia Corporation
* Author: Juha Yrjölä <juha.yrjola@nokia.com>
* DMA channel linking for 1610 by Samuel Ortiz <samuel.ortiz@nokia.com>
* Graphics DMA and LCD DMA graphics tranformations
* by Imre Deak <imre.deak@nokia.com>
* OMAP2/3 support Copyright (C) 2004-2007 Texas Instruments, Inc.
* Some functions based on earlier dma-omap.c Copyright (C) 2001 RidgeRun, Inc.
*
* Copyright (C) 2009 Texas Instruments
* Added OMAP4 support - Santosh Shilimkar <santosh.shilimkar@ti.com>
*
* Copyright (C) 2010 Texas Instruments Incorporated - http://www.ti.com/
* Converted DMA library into platform driver
* - G, Manjunath Kondaiah <manjugk@ti.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/err.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/of.h>
#include <linux/omap-dma.h>
#include "soc.h"
#include "omap_hwmod.h"
#include "omap_device.h"
static enum omap_reg_offsets dma_common_ch_end;
static const struct omap_dma_reg reg_map[] = {
[REVISION] = { 0x0000, 0x00, OMAP_DMA_REG_32BIT },
[GCR] = { 0x0078, 0x00, OMAP_DMA_REG_32BIT },
[IRQSTATUS_L0] = { 0x0008, 0x00, OMAP_DMA_REG_32BIT },
[IRQSTATUS_L1] = { 0x000c, 0x00, OMAP_DMA_REG_32BIT },
[IRQSTATUS_L2] = { 0x0010, 0x00, OMAP_DMA_REG_32BIT },
[IRQSTATUS_L3] = { 0x0014, 0x00, OMAP_DMA_REG_32BIT },
[IRQENABLE_L0] = { 0x0018, 0x00, OMAP_DMA_REG_32BIT },
[IRQENABLE_L1] = { 0x001c, 0x00, OMAP_DMA_REG_32BIT },
[IRQENABLE_L2] = { 0x0020, 0x00, OMAP_DMA_REG_32BIT },
[IRQENABLE_L3] = { 0x0024, 0x00, OMAP_DMA_REG_32BIT },
[SYSSTATUS] = { 0x0028, 0x00, OMAP_DMA_REG_32BIT },
[OCP_SYSCONFIG] = { 0x002c, 0x00, OMAP_DMA_REG_32BIT },
[CAPS_0] = { 0x0064, 0x00, OMAP_DMA_REG_32BIT },
[CAPS_2] = { 0x006c, 0x00, OMAP_DMA_REG_32BIT },
[CAPS_3] = { 0x0070, 0x00, OMAP_DMA_REG_32BIT },
[CAPS_4] = { 0x0074, 0x00, OMAP_DMA_REG_32BIT },
/* Common register offsets */
[CCR] = { 0x0080, 0x60, OMAP_DMA_REG_32BIT },
[CLNK_CTRL] = { 0x0084, 0x60, OMAP_DMA_REG_32BIT },
[CICR] = { 0x0088, 0x60, OMAP_DMA_REG_32BIT },
[CSR] = { 0x008c, 0x60, OMAP_DMA_REG_32BIT },
[CSDP] = { 0x0090, 0x60, OMAP_DMA_REG_32BIT },
[CEN] = { 0x0094, 0x60, OMAP_DMA_REG_32BIT },
[CFN] = { 0x0098, 0x60, OMAP_DMA_REG_32BIT },
[CSEI] = { 0x00a4, 0x60, OMAP_DMA_REG_32BIT },
[CSFI] = { 0x00a8, 0x60, OMAP_DMA_REG_32BIT },
[CDEI] = { 0x00ac, 0x60, OMAP_DMA_REG_32BIT },
[CDFI] = { 0x00b0, 0x60, OMAP_DMA_REG_32BIT },
[CSAC] = { 0x00b4, 0x60, OMAP_DMA_REG_32BIT },
[CDAC] = { 0x00b8, 0x60, OMAP_DMA_REG_32BIT },
/* Channel specific register offsets */
[CSSA] = { 0x009c, 0x60, OMAP_DMA_REG_32BIT },
[CDSA] = { 0x00a0, 0x60, OMAP_DMA_REG_32BIT },
[CCEN] = { 0x00bc, 0x60, OMAP_DMA_REG_32BIT },
[CCFN] = { 0x00c0, 0x60, OMAP_DMA_REG_32BIT },
[COLOR] = { 0x00c4, 0x60, OMAP_DMA_REG_32BIT },
/* OMAP4 specific registers */
[CDP] = { 0x00d0, 0x60, OMAP_DMA_REG_32BIT },
[CNDP] = { 0x00d4, 0x60, OMAP_DMA_REG_32BIT },
[CCDN] = { 0x00d8, 0x60, OMAP_DMA_REG_32BIT },
};
static void __iomem *dma_base;
static inline void dma_write(u32 val, int reg, int lch)
{
void __iomem *addr = dma_base;
addr += reg_map[reg].offset;
addr += reg_map[reg].stride * lch;
writel_relaxed(val, addr);
}
static inline u32 dma_read(int reg, int lch)
{
void __iomem *addr = dma_base;
addr += reg_map[reg].offset;
addr += reg_map[reg].stride * lch;
return readl_relaxed(addr);
}
static void omap2_clear_dma(int lch)
{
int i;
for (i = CSDP; i <= dma_common_ch_end; i += 1)
dma_write(0, i, lch);
}
static void omap2_show_dma_caps(void)
{
u8 revision = dma_read(REVISION, 0) & 0xff;
printk(KERN_INFO "OMAP DMA hardware revision %d.%d\n",
revision >> 4, revision & 0xf);
return;
}
static unsigned configure_dma_errata(void)
{
unsigned errata = 0;
/*
* Errata applicable for OMAP2430ES1.0 and all omap2420
*
* I.
* Erratum ID: Not Available
* Inter Frame DMA buffering issue DMA will wrongly
* buffer elements if packing and bursting is enabled. This might
* result in data gets stalled in FIFO at the end of the block.
* Workaround: DMA channels must have BUFFERING_DISABLED bit set to
* guarantee no data will stay in the DMA FIFO in case inter frame
* buffering occurs
*
* II.
* Erratum ID: Not Available
* DMA may hang when several channels are used in parallel
* In the following configuration, DMA channel hanging can occur:
* a. Channel i, hardware synchronized, is enabled
* b. Another channel (Channel x), software synchronized, is enabled.
* c. Channel i is disabled before end of transfer
* d. Channel i is reenabled.
* e. Steps 1 to 4 are repeated a certain number of times.
* f. A third channel (Channel y), software synchronized, is enabled.
* Channel x and Channel y may hang immediately after step 'f'.
* Workaround:
* For any channel used - make sure NextLCH_ID is set to the value j.
*/
if (cpu_is_omap2420() || (cpu_is_omap2430() &&
(omap_type() == OMAP2430_REV_ES1_0))) {
SET_DMA_ERRATA(DMA_ERRATA_IFRAME_BUFFERING);
SET_DMA_ERRATA(DMA_ERRATA_PARALLEL_CHANNELS);
}
/*
* Erratum ID: i378: OMAP2+: sDMA Channel is not disabled
* after a transaction error.
* Workaround: SW should explicitely disable the channel.
*/
if (cpu_class_is_omap2())
SET_DMA_ERRATA(DMA_ERRATA_i378);
/*
* Erratum ID: i541: sDMA FIFO draining does not finish
* If sDMA channel is disabled on the fly, sDMA enters standby even
* through FIFO Drain is still in progress
* Workaround: Put sDMA in NoStandby more before a logical channel is
* disabled, then put it back to SmartStandby right after the channel
* finishes FIFO draining.
*/
if (cpu_is_omap34xx())
SET_DMA_ERRATA(DMA_ERRATA_i541);
/*
* Erratum ID: i88 : Special programming model needed to disable DMA
* before end of block.
* Workaround: software must ensure that the DMA is configured in No
* Standby mode(DMAx_OCP_SYSCONFIG.MIDLEMODE = "01")
*/
if (omap_type() == OMAP3430_REV_ES1_0)
SET_DMA_ERRATA(DMA_ERRATA_i88);
/*
* Erratum 3.2/3.3: sometimes 0 is returned if CSAC/CDAC is
* read before the DMA controller finished disabling the channel.
*/
SET_DMA_ERRATA(DMA_ERRATA_3_3);
/*
* Erratum ID: Not Available
* A bug in ROM code leaves IRQ status for channels 0 and 1 uncleared
* after secure sram context save and restore.
* Work around: Hence we need to manually clear those IRQs to avoid
* spurious interrupts. This affects only secure devices.
*/
if (cpu_is_omap34xx() && (omap_type() != OMAP2_DEVICE_TYPE_GP))
SET_DMA_ERRATA(DMA_ROMCODE_BUG);
return errata;
}
static struct omap_system_dma_plat_info dma_plat_info __initdata = {
.reg_map = reg_map,
.channel_stride = 0x60,
.show_dma_caps = omap2_show_dma_caps,
.clear_dma = omap2_clear_dma,
.dma_write = dma_write,
.dma_read = dma_read,
};
static struct platform_device_info omap_dma_dev_info = {
.name = "omap-dma-engine",
.id = -1,
.dma_mask = DMA_BIT_MASK(32),
};
/* One time initializations */
static int __init omap2_system_dma_init_dev(struct omap_hwmod *oh, void *unused)
{
struct platform_device *pdev;
struct omap_system_dma_plat_info p;
struct omap_dma_dev_attr *d;
struct resource *mem;
char *name = "omap_dma_system";
p = dma_plat_info;
p.dma_attr = (struct omap_dma_dev_attr *)oh->dev_attr;
p.errata = configure_dma_errata();
pdev = omap_device_build(name, 0, oh, &p, sizeof(p));
if (IS_ERR(pdev)) {
pr_err("%s: Can't build omap_device for %s:%s.\n",
__func__, name, oh->name);
return PTR_ERR(pdev);
}
omap_dma_dev_info.res = pdev->resource;
omap_dma_dev_info.num_res = pdev->num_resources;
mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!mem) {
dev_err(&pdev->dev, "%s: no mem resource\n", __func__);
return -EINVAL;
}
dma_base = ioremap(mem->start, resource_size(mem));
if (!dma_base) {
dev_err(&pdev->dev, "%s: ioremap fail\n", __func__);
return -ENOMEM;
}
d = oh->dev_attr;
if (cpu_is_omap34xx() && (omap_type() != OMAP2_DEVICE_TYPE_GP))
d->dev_caps |= HS_CHANNELS_RESERVED;
if (platform_get_irq_byname(pdev, "0") < 0)
d->dev_caps |= DMA_ENGINE_HANDLE_IRQ;
/* Check the capabilities register for descriptor loading feature */
if (dma_read(CAPS_0, 0) & DMA_HAS_DESCRIPTOR_CAPS)
dma_common_ch_end = CCDN;
else
dma_common_ch_end = CCFN;
return 0;
}
static int __init omap2_system_dma_init(void)
{
struct platform_device *pdev;
int res;
res = omap_hwmod_for_each_by_class("dma",
omap2_system_dma_init_dev, NULL);
if (res)
return res;
if (of_have_populated_dt())
return res;
pdev = platform_device_register_full(&omap_dma_dev_info);
if (IS_ERR(pdev))
return PTR_ERR(pdev);
return res;
}
omap_arch_initcall(omap2_system_dma_init);
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