/* * 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" #define OMAP2_DMA_STRIDE 0x60 static u32 errata; static u8 dma_stride; static struct omap_dma_dev_attr *d; static enum omap_reg_offsets dma_common_ch_start, dma_common_ch_end; static u16 reg_map[] = { [REVISION] = 0x00, [GCR] = 0x78, [IRQSTATUS_L0] = 0x08, [IRQSTATUS_L1] = 0x0c, [IRQSTATUS_L2] = 0x10, [IRQSTATUS_L3] = 0x14, [IRQENABLE_L0] = 0x18, [IRQENABLE_L1] = 0x1c, [IRQENABLE_L2] = 0x20, [IRQENABLE_L3] = 0x24, [SYSSTATUS] = 0x28, [OCP_SYSCONFIG] = 0x2c, [CAPS_0] = 0x64, [CAPS_2] = 0x6c, [CAPS_3] = 0x70, [CAPS_4] = 0x74, /* Common register offsets */ [CCR] = 0x80, [CLNK_CTRL] = 0x84, [CICR] = 0x88, [CSR] = 0x8c, [CSDP] = 0x90, [CEN] = 0x94, [CFN] = 0x98, [CSEI] = 0xa4, [CSFI] = 0xa8, [CDEI] = 0xac, [CDFI] = 0xb0, [CSAC] = 0xb4, [CDAC] = 0xb8, /* Channel specific register offsets */ [CSSA] = 0x9c, [CDSA] = 0xa0, [CCEN] = 0xbc, [CCFN] = 0xc0, [COLOR] = 0xc4, /* OMAP4 specific registers */ [CDP] = 0xd0, [CNDP] = 0xd4, [CCDN] = 0xd8, }; static void __iomem *dma_base; static inline void dma_write(u32 val, int reg, int lch) { u8 stride; u32 offset; stride = (reg >= dma_common_ch_start) ? dma_stride : 0; offset = reg_map[reg] + (stride * lch); __raw_writel(val, dma_base + offset); } static inline u32 dma_read(int reg, int lch) { u8 stride; u32 offset, val; stride = (reg >= dma_common_ch_start) ? dma_stride : 0; offset = reg_map[reg] + (stride * lch); val = __raw_readl(dma_base + offset); return val; } static inline void omap2_disable_irq_lch(int lch) { u32 val; val = dma_read(IRQENABLE_L0, lch); val &= ~(1 << lch); dma_write(val, IRQENABLE_L0, lch); } static void omap2_clear_dma(int lch) { int i = dma_common_ch_start; for (; 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 u32 configure_dma_errata(void) { /* * 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; } /* 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 resource *mem; char *name = "omap_dma_system"; dma_stride = OMAP2_DMA_STRIDE; dma_common_ch_start = CSDP; p = kzalloc(sizeof(struct omap_system_dma_plat_info), GFP_KERNEL); if (!p) { pr_err("%s: Unable to allocate pdata for %s:%s\n", __func__, name, oh->name); return -ENOMEM; } p->dma_attr = (struct omap_dma_dev_attr *)oh->dev_attr; p->disable_irq_lch = omap2_disable_irq_lch; p->show_dma_caps = omap2_show_dma_caps; p->clear_dma = omap2_clear_dma; p->dma_write = dma_write; p->dma_read = dma_read; p->clear_lch_regs = NULL; p->errata = configure_dma_errata(); pdev = omap_device_build(name, 0, oh, p, sizeof(*p)); kfree(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); } 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; d->chan = kzalloc(sizeof(struct omap_dma_lch) * (d->lch_count), GFP_KERNEL); if (!d->chan) { dev_err(&pdev->dev, "%s: kzalloc fail\n", __func__); return -ENOMEM; } if (cpu_is_omap34xx() && (omap_type() != OMAP2_DEVICE_TYPE_GP)) d->dev_caps |= HS_CHANNELS_RESERVED; /* 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 const struct platform_device_info omap_dma_dev_info = { .name = "omap-dma-engine", .id = -1, .dma_mask = DMA_BIT_MASK(32), }; 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);