| /* SPDX-License-Identifier: GPL-2.0-only */ |
| /* This file is part of the coreboot project. */ |
| |
| #include <device/mmio.h> |
| #include <console/console.h> |
| #include <stdint.h> |
| #include <soc/addressmap.h> |
| #include <soc/dma.h> |
| #include <stddef.h> |
| |
| struct apb_dma * const apb_dma = (struct apb_dma *)TEGRA_APB_DMA_BASE; |
| |
| #define APB_DMA_OFFSET(n) \ |
| (struct apb_dma_channel_regs *)(TEGRA_APB_DMA_BASE + n) |
| struct apb_dma_channel apb_dma_channels[] = { |
| { .num = 0, .regs = APB_DMA_OFFSET(0x1000) }, |
| { .num = 1, .regs = APB_DMA_OFFSET(0x1040) }, |
| { .num = 2, .regs = APB_DMA_OFFSET(0x1080) }, |
| { .num = 3, .regs = APB_DMA_OFFSET(0x10c0) }, |
| { .num = 4, .regs = APB_DMA_OFFSET(0x1100) }, |
| { .num = 5, .regs = APB_DMA_OFFSET(0x1140) }, |
| { .num = 6, .regs = APB_DMA_OFFSET(0x1180) }, |
| { .num = 7, .regs = APB_DMA_OFFSET(0x11c0) }, |
| { .num = 8, .regs = APB_DMA_OFFSET(0x1200) }, |
| { .num = 9, .regs = APB_DMA_OFFSET(0x1240) }, |
| { .num = 10, .regs = APB_DMA_OFFSET(0x1280) }, |
| { .num = 11, .regs = APB_DMA_OFFSET(0x12c0) }, |
| { .num = 12, .regs = APB_DMA_OFFSET(0x1300) }, |
| { .num = 13, .regs = APB_DMA_OFFSET(0x1340) }, |
| { .num = 14, .regs = APB_DMA_OFFSET(0x1380) }, |
| { .num = 15, .regs = APB_DMA_OFFSET(0x13c0) }, |
| { .num = 16, .regs = APB_DMA_OFFSET(0x1400) }, |
| { .num = 17, .regs = APB_DMA_OFFSET(0x1440) }, |
| { .num = 18, .regs = APB_DMA_OFFSET(0x1480) }, |
| { .num = 19, .regs = APB_DMA_OFFSET(0x14c0) }, |
| { .num = 20, .regs = APB_DMA_OFFSET(0x1500) }, |
| { .num = 21, .regs = APB_DMA_OFFSET(0x1540) }, |
| { .num = 22, .regs = APB_DMA_OFFSET(0x1580) }, |
| { .num = 23, .regs = APB_DMA_OFFSET(0x15c0) }, |
| { .num = 24, .regs = APB_DMA_OFFSET(0x1600) }, |
| { .num = 25, .regs = APB_DMA_OFFSET(0x1640) }, |
| { .num = 26, .regs = APB_DMA_OFFSET(0x1680) }, |
| { .num = 27, .regs = APB_DMA_OFFSET(0x16c0) }, |
| { .num = 28, .regs = APB_DMA_OFFSET(0x1700) }, |
| { .num = 29, .regs = APB_DMA_OFFSET(0x1740) }, |
| { .num = 30, .regs = APB_DMA_OFFSET(0x1780) }, |
| { .num = 31, .regs = APB_DMA_OFFSET(0x17c0) }, |
| }; |
| |
| int dma_busy(struct apb_dma_channel * const channel) |
| { |
| /* |
| * In continuous mode, the BSY_n bit in APB_DMA_STATUS and |
| * BSY in APBDMACHAN_CHANNEL_n_STA_0 will remain set as '1' so long |
| * as the channel is enabled. So for this function we'll use the |
| * DMA_ACTIVITY bit in case of continuous mode. |
| * |
| * However, for ONCE mode, the BSY_n bit in APB_DMA_STATUS will be used |
| * to determine end of dma operation. |
| */ |
| uint32_t bit; |
| |
| if (read32(&channel->regs->csr) & APB_CSR_ONCE) |
| /* Once mode */ |
| bit = APB_STA_BSY; |
| else |
| /* Continuous mode */ |
| bit = APB_STA_DMA_ACTIVITY; |
| |
| return read32(&channel->regs->sta) & bit ? 1 : 0; |
| } |
| /* claim a DMA channel */ |
| struct apb_dma_channel * const dma_claim(void) |
| { |
| int i; |
| struct apb_dma_channel_regs *regs = NULL; |
| |
| /* |
| * Set global enable bit, otherwise register access to channel |
| * DMA registers will not be possible. |
| */ |
| setbits32(&apb_dma->command, APB_COMMAND_GEN); |
| |
| for (i = 0; i < ARRAY_SIZE(apb_dma_channels); i++) { |
| regs = apb_dma_channels[i].regs; |
| |
| if (!apb_dma_channels[i].in_use) { |
| u32 status = read32(®s->sta); |
| if (status & (1 << i)) { |
| /* FIXME: should this be fatal? */ |
| printk(BIOS_DEBUG, "%s: DMA channel %d busy?\n", |
| __func__, i); |
| } |
| break; |
| } |
| } |
| |
| if (i == ARRAY_SIZE(apb_dma_channels)) |
| return NULL; |
| |
| apb_dma_channels[i].in_use = 1; |
| return &apb_dma_channels[i]; |
| } |
| |
| /* release a DMA channel */ |
| void dma_release(struct apb_dma_channel * const channel) |
| { |
| int i; |
| |
| /* FIXME: make this "thread" friendly */ |
| while (dma_busy(channel)) |
| ; |
| |
| channel->in_use = 0; |
| |
| /* clear the global enable bit if no channels are in use */ |
| for (i = 0; i < ARRAY_SIZE(apb_dma_channels); i++) { |
| if (apb_dma_channels[i].in_use) |
| return; |
| } |
| |
| clrbits32(&apb_dma->command, APB_COMMAND_GEN); |
| } |
| |
| int dma_start(struct apb_dma_channel * const channel) |
| { |
| struct apb_dma_channel_regs *regs = channel->regs; |
| |
| /* Set ENB bit for this channel */ |
| setbits32(®s->csr, APB_CSR_ENB); |
| |
| return 0; |
| } |
| |
| int dma_stop(struct apb_dma_channel * const channel) |
| { |
| struct apb_dma_channel_regs *regs = channel->regs; |
| |
| /* Clear ENB bit for this channel */ |
| clrbits32(®s->csr, APB_CSR_ENB); |
| |
| return 0; |
| } |