arch/arm/mach-omap2/dma.c

   1 /*
   2  * OMAP2+ DMA driver
   3  *
   4  * Copyright (C) 2003 - 2008 Nokia Corporation
   5  * Author: Juha Yrjölä <juha.yrjola@nokia.com>
   6  * DMA channel linking for 1610 by Samuel Ortiz <samuel.ortiz@nokia.com>
   7  * Graphics DMA and LCD DMA graphics tranformations
   8  * by Imre Deak <imre.deak@nokia.com>
   9  * OMAP2/3 support Copyright (C) 2004-2007 Texas Instruments, Inc.
  10  * Some functions based on earlier dma-omap.c Copyright (C) 2001 RidgeRun, Inc.
  11  *
  12  * Copyright (C) 2009 Texas Instruments
  13  * Added OMAP4 support - Santosh Shilimkar <santosh.shilimkar@ti.com>
  14  *
  15  * Copyright (C) 2010 Texas Instruments Incorporated - http://www.ti.com/
  16  * Converted DMA library into platform driver
  17  *      - G, Manjunath Kondaiah <manjugk@ti.com>
  18  *
  19  * This program is free software; you can redistribute it and/or modify
  20  * it under the terms of the GNU General Public License version 2 as
  21  * published by the Free Software Foundation.
  22  */
  23
  24 #include <linux/err.h>
  25 #include <linux/io.h>
  26 #include <linux/slab.h>
  27 #include <linux/module.h>
  28 #include <linux/init.h>
  29 #include <linux/device.h>
  30
  31 #include <plat/omap_hwmod.h>
  32 #include <plat/omap_device.h>
  33 #include <plat/dma.h>
  34
  35 #define OMAP2_DMA_STRIDE        0x60
  36
  37 static u32 errata;
  38 static u8 dma_stride;
  39
  40 static struct omap_dma_dev_attr *d;
  41
  42 static enum omap_reg_offsets dma_common_ch_start, dma_common_ch_end;
  43
  44 static u16 reg_map[] = {
  45         [REVISION]              = 0x00,
  46         [GCR]                   = 0x78,
  47         [IRQSTATUS_L0]          = 0x08,
  48         [IRQSTATUS_L1]          = 0x0c,
  49         [IRQSTATUS_L2]          = 0x10,
  50         [IRQSTATUS_L3]          = 0x14,
  51         [IRQENABLE_L0]          = 0x18,
  52         [IRQENABLE_L1]          = 0x1c,
  53         [IRQENABLE_L2]          = 0x20,
  54         [IRQENABLE_L3]          = 0x24,
  55         [SYSSTATUS]             = 0x28,
  56         [OCP_SYSCONFIG]         = 0x2c,
  57         [CAPS_0]                = 0x64,
  58         [CAPS_2]                = 0x6c,
  59         [CAPS_3]                = 0x70,
  60         [CAPS_4]                = 0x74,
  61
  62         /* Common register offsets */
  63         [CCR]                   = 0x80,
  64         [CLNK_CTRL]             = 0x84,
  65         [CICR]                  = 0x88,
  66         [CSR]                   = 0x8c,
  67         [CSDP]                  = 0x90,
  68         [CEN]                   = 0x94,
  69         [CFN]                   = 0x98,
  70         [CSEI]                  = 0xa4,
  71         [CSFI]                  = 0xa8,
  72         [CDEI]                  = 0xac,
  73         [CDFI]                  = 0xb0,
  74         [CSAC]                  = 0xb4,
  75         [CDAC]                  = 0xb8,
  76
  77         /* Channel specific register offsets */
  78         [CSSA]                  = 0x9c,
  79         [CDSA]                  = 0xa0,
  80         [CCEN]                  = 0xbc,
  81         [CCFN]                  = 0xc0,
  82         [COLOR]                 = 0xc4,
  83
  84         /* OMAP4 specific registers */
  85         [CDP]                   = 0xd0,
  86         [CNDP]                  = 0xd4,
  87         [CCDN]                  = 0xd8,
  88 };
  89
  90 static struct omap_device_pm_latency omap2_dma_latency[] = {
  91         {
  92                 .deactivate_func = omap_device_idle_hwmods,
  93                 .activate_func   = omap_device_enable_hwmods,
  94                 .flags           = OMAP_DEVICE_LATENCY_AUTO_ADJUST,
  95         },
  96 };
  97
  98 static void __iomem *dma_base;
  99 static inline void dma_write(u32 val, int reg, int lch)
 100 {
 101         u8  stride;
 102         u32 offset;
 103
 104         stride = (reg >= dma_common_ch_start) ? dma_stride : 0;
 105         offset = reg_map[reg] + (stride * lch);
 106         __raw_writel(val, dma_base + offset);
 107 }
 108
 109 static inline u32 dma_read(int reg, int lch)
 110 {
 111         u8 stride;
 112         u32 offset, val;
 113
 114         stride = (reg >= dma_common_ch_start) ? dma_stride : 0;
 115         offset = reg_map[reg] + (stride * lch);
 116         val = __raw_readl(dma_base + offset);
 117         return val;
 118 }
 119
 120 static inline void omap2_disable_irq_lch(int lch)
 121 {
 122         u32 val;
 123
 124         val = dma_read(IRQENABLE_L0, lch);
 125         val &= ~(1 << lch);
 126         dma_write(val, IRQENABLE_L0, lch);
 127 }
 128
 129 static void omap2_clear_dma(int lch)
 130 {
 131         int i = dma_common_ch_start;
 132
 133         for (; i <= dma_common_ch_end; i += 1)
 134                 dma_write(0, i, lch);
 135 }
 136
 137 static void omap2_show_dma_caps(void)
 138 {
 139         u8 revision = dma_read(REVISION, 0) & 0xff;
 140         printk(KERN_INFO "OMAP DMA hardware revision %d.%d\n",
 141                                 revision >> 4, revision & 0xf);
 142         return;
 143 }
 144
 145 static u32 configure_dma_errata(void)
 146 {
 147
 148         /*
 149          * Errata applicable for OMAP2430ES1.0 and all omap2420
 150          *
 151          * I.
 152          * Erratum ID: Not Available
 153          * Inter Frame DMA buffering issue DMA will wrongly
 154          * buffer elements if packing and bursting is enabled. This might
 155          * result in data gets stalled in FIFO at the end of the block.
 156          * Workaround: DMA channels must have BUFFERING_DISABLED bit set to
 157          * guarantee no data will stay in the DMA FIFO in case inter frame
 158          * buffering occurs
 159          *
 160          * II.
 161          * Erratum ID: Not Available
 162          * DMA may hang when several channels are used in parallel
 163          * In the following configuration, DMA channel hanging can occur:
 164          * a. Channel i, hardware synchronized, is enabled
 165          * b. Another channel (Channel x), software synchronized, is enabled.
 166          * c. Channel i is disabled before end of transfer
 167          * d. Channel i is reenabled.
 168          * e. Steps 1 to 4 are repeated a certain number of times.
 169          * f. A third channel (Channel y), software synchronized, is enabled.
 170          * Channel x and Channel y may hang immediately after step 'f'.
 171          * Workaround:
 172          * For any channel used - make sure NextLCH_ID is set to the value j.
 173          */
 174         if (cpu_is_omap2420() || (cpu_is_omap2430() &&
 175                                 (omap_type() == OMAP2430_REV_ES1_0))) {
 176
 177                 SET_DMA_ERRATA(DMA_ERRATA_IFRAME_BUFFERING);
 178                 SET_DMA_ERRATA(DMA_ERRATA_PARALLEL_CHANNELS);
 179         }
 180
 181         /*
 182          * Erratum ID: i378: OMAP2+: sDMA Channel is not disabled
 183          * after a transaction error.
 184          * Workaround: SW should explicitely disable the channel.
 185          */
 186         if (cpu_class_is_omap2())
 187                 SET_DMA_ERRATA(DMA_ERRATA_i378);
 188
 189         /*
 190          * Erratum ID: i541: sDMA FIFO draining does not finish
 191          * If sDMA channel is disabled on the fly, sDMA enters standby even
 192          * through FIFO Drain is still in progress
 193          * Workaround: Put sDMA in NoStandby more before a logical channel is
 194          * disabled, then put it back to SmartStandby right after the channel
 195          * finishes FIFO draining.
 196          */
 197         if (cpu_is_omap34xx())
 198                 SET_DMA_ERRATA(DMA_ERRATA_i541);
 199
 200         /*
 201          * Erratum ID: i88 : Special programming model needed to disable DMA
 202          * before end of block.
 203          * Workaround: software must ensure that the DMA is configured in No
 204          * Standby mode(DMAx_OCP_SYSCONFIG.MIDLEMODE = "01")
 205          */
 206         if (omap_type() == OMAP3430_REV_ES1_0)
 207                 SET_DMA_ERRATA(DMA_ERRATA_i88);
 208
 209         /*
 210          * Erratum 3.2/3.3: sometimes 0 is returned if CSAC/CDAC is
 211          * read before the DMA controller finished disabling the channel.
 212          */
 213         SET_DMA_ERRATA(DMA_ERRATA_3_3);
 214
 215         /*
 216          * Erratum ID: Not Available
 217          * A bug in ROM code leaves IRQ status for channels 0 and 1 uncleared
 218          * after secure sram context save and restore.
 219          * Work around: Hence we need to manually clear those IRQs to avoid
 220          * spurious interrupts. This affects only secure devices.
 221          */
 222         if (cpu_is_omap34xx() && (omap_type() != OMAP2_DEVICE_TYPE_GP))
 223                 SET_DMA_ERRATA(DMA_ROMCODE_BUG);
 224
 225         return errata;
 226 }
 227
 228 /* One time initializations */
 229 static int __init omap2_system_dma_init_dev(struct omap_hwmod *oh, void *unused)
 230 {
 231         struct omap_device                      *od;
 232         struct omap_system_dma_plat_info        *p;
 233         struct resource                         *mem;
 234         char                                    *name = "omap_dma_system";
 235
 236         dma_stride              = OMAP2_DMA_STRIDE;
 237         dma_common_ch_start     = CSDP;
 238         if (cpu_is_omap3630() || cpu_is_omap4430())
 239                 dma_common_ch_end = CCDN;
 240         else
 241                 dma_common_ch_end = CCFN;
 242
 243         p = kzalloc(sizeof(struct omap_system_dma_plat_info), GFP_KERNEL);
 244         if (!p) {
 245                 pr_err("%s: Unable to allocate pdata for %s:%s\n",
 246                         __func__, name, oh->name);
 247                 return -ENOMEM;
 248         }
 249
 250         p->dma_attr             = (struct omap_dma_dev_attr *)oh->dev_attr;
 251         p->disable_irq_lch      = omap2_disable_irq_lch;
 252         p->show_dma_caps        = omap2_show_dma_caps;
 253         p->clear_dma            = omap2_clear_dma;
 254         p->dma_write            = dma_write;
 255         p->dma_read             = dma_read;
 256
 257         p->clear_lch_regs       = NULL;
 258
 259         p->errata               = configure_dma_errata();
 260
 261         od = omap_device_build(name, 0, oh, p, sizeof(*p),
 262                         omap2_dma_latency, ARRAY_SIZE(omap2_dma_latency), 0);
 263         kfree(p);
 264         if (IS_ERR(od)) {
 265                 pr_err("%s: Cant build omap_device for %s:%s.\n",
 266                         __func__, name, oh->name);
 267                 return PTR_ERR(od);
 268         }
 269
 270         mem = platform_get_resource(&od->pdev, IORESOURCE_MEM, 0);
 271         if (!mem) {
 272                 dev_err(&od->pdev.dev, "%s: no mem resource\n", __func__);
 273                 return -EINVAL;
 274         }
 275         dma_base = ioremap(mem->start, resource_size(mem));
 276         if (!dma_base) {
 277                 dev_err(&od->pdev.dev, "%s: ioremap fail\n", __func__);
 278                 return -ENOMEM;
 279         }
 280
 281         d = oh->dev_attr;
 282         d->chan = kzalloc(sizeof(struct omap_dma_lch) *
 283                                         (d->lch_count), GFP_KERNEL);
 284
 285         if (!d->chan) {
 286                 dev_err(&od->pdev.dev, "%s: kzalloc fail\n", __func__);
 287                 return -ENOMEM;
 288         }
 289         return 0;
 290 }
 291
 292 static int __init omap2_system_dma_init(void)
 293 {
 294         return omap_hwmod_for_each_by_class("dma",
 295                         omap2_system_dma_init_dev, NULL);
 296 }
 297 arch_initcall(omap2_system_dma_init);