drivers/dma/lpc32xx_dma.c

   1 /*
   2  * Copyright (C) 2008 by NXP Semiconductors
   3  * @Author: Kevin Wells
   4  * @Descr: LPC3250 DMA controller interface support functions
   5  *
   6  * Copyright (c) 2015 Tyco Fire Protection Products.
   7  *
   8  * SPDX-License-Identifier:     GPL-2.0+
   9  */
  10
  11 #include <common.h>
  12 #include <errno.h>
  13 #include <asm/arch/dma.h>
  14 #include <asm/arch/cpu.h>
  15 #include <asm/arch/clk.h>
  16 #include <asm/arch/sys_proto.h>
  17 #include <asm/io.h>
  18
  19 /* DMA controller channel register structure */
  20 struct dmac_chan_reg {
  21         u32 src_addr;
  22         u32 dest_addr;
  23         u32 lli;
  24         u32 control;
  25         u32 config_ch;
  26         u32 reserved[3];
  27 };
  28
  29 /* DMA controller register structures */
  30 struct dma_reg {
  31         u32 int_stat;
  32         u32 int_tc_stat;
  33         u32 int_tc_clear;
  34         u32 int_err_stat;
  35         u32 int_err_clear;
  36         u32 raw_tc_stat;
  37         u32 raw_err_stat;
  38         u32 chan_enable;
  39         u32 sw_burst_req;
  40         u32 sw_single_req;
  41         u32 sw_last_burst_req;
  42         u32 sw_last_single_req;
  43         u32 config;
  44         u32 sync;
  45         u32 reserved[50];
  46         struct dmac_chan_reg dma_chan[8];
  47 };
  48
  49 #define DMA_NO_OF_CHANNELS      8
  50
  51 /* config register definitions */
  52 #define DMAC_CTRL_ENABLE        (1 << 0) /* For enabling the DMA controller */
  53
  54 static u32 alloc_ch;
  55
  56 static struct dma_reg *dma = (struct dma_reg *)DMA_BASE;
  57
  58 int lpc32xx_dma_get_channel(void)
  59 {
  60         int i;
  61
  62         if (!alloc_ch) { /* First time caller */
  63                 /*
  64                  * DMA clock are enable by "lpc32xx_dma_init()" and should
  65                  * be call by board "board_early_init_f()" function.
  66                  */
  67
  68                 /*
  69                  * Make sure DMA controller and all channels are disabled.
  70                  * Controller is in little-endian mode. Disable sync signals.
  71                  */
  72                 writel(0, &dma->config);
  73                 writel(0, &dma->sync);
  74
  75                 /* Clear interrupt and error statuses */
  76                 writel(0xFF, &dma->int_tc_clear);
  77                 writel(0xFF, &dma->raw_tc_stat);
  78                 writel(0xFF, &dma->int_err_clear);
  79                 writel(0xFF, &dma->raw_err_stat);
  80
  81                 /* Enable DMA controller */
  82                 writel(DMAC_CTRL_ENABLE, &dma->config);
  83         }
  84
  85         i = ffz(alloc_ch);
  86
  87         /* Check if all the available channels are busy */
  88         if (unlikely(i == DMA_NO_OF_CHANNELS))
  89                 return -1;
  90         alloc_ch |= BIT_MASK(i);
  91         return i;
  92 }
  93
  94 int lpc32xx_dma_start_xfer(unsigned int channel,
  95                            const struct lpc32xx_dmac_ll *desc, u32 config)
  96 {
  97         if (unlikely(((BIT_MASK(channel) & alloc_ch) == 0) ||
  98                      (channel >= DMA_NO_OF_CHANNELS))) {
  99                 error("Request for xfer on unallocated channel %d", channel);
 100                 return -1;
 101         }
 102         writel(BIT_MASK(channel), &dma->int_tc_clear);
 103         writel(BIT_MASK(channel), &dma->int_err_clear);
 104         writel(desc->dma_src, &dma->dma_chan[channel].src_addr);
 105         writel(desc->dma_dest, &dma->dma_chan[channel].dest_addr);
 106         writel(desc->next_lli, &dma->dma_chan[channel].lli);
 107         writel(desc->next_ctrl, &dma->dma_chan[channel].control);
 108         writel(config, &dma->dma_chan[channel].config_ch);
 109
 110         return 0;
 111 }
 112
 113 int lpc32xx_dma_wait_status(unsigned int channel)
 114 {
 115         unsigned long start;
 116         u32 reg;
 117
 118         /* Check if given channel is valid */
 119         if (unlikely(channel >= DMA_NO_OF_CHANNELS)) {
 120                 error("Request for status on unallocated channel %d", channel);
 121                 return -1;
 122         }
 123
 124         start = get_timer(0);
 125         while (1) {
 126                 reg = readl(&dma->raw_tc_stat);
 127                 reg |= readl(dma->raw_err_stat);
 128                 if (reg & BIT_MASK(channel))
 129                         break;
 130
 131                 if (get_timer(start) > CONFIG_SYS_HZ) {
 132                         error("DMA status timeout channel %d\n", channel);
 133                         return -ETIMEDOUT;
 134                 }
 135                 udelay(1);
 136         }
 137
 138         if (unlikely(readl(&dma->raw_err_stat) & BIT_MASK(channel))) {
 139                 setbits_le32(&dma->int_err_clear, BIT_MASK(channel));
 140                 setbits_le32(&dma->raw_err_stat, BIT_MASK(channel));
 141                 error("DMA error on channel %d\n", channel);
 142                 return -1;
 143         }
 144         setbits_le32(&dma->int_tc_clear, BIT_MASK(channel));
 145         setbits_le32(&dma->raw_tc_stat, BIT_MASK(channel));
 146         return 0;
 147 }