diff options
Diffstat (limited to 'arch/mips/lantiq/xway/dma.c')
| -rw-r--r-- | arch/mips/lantiq/xway/dma.c | 274 |
1 files changed, 274 insertions, 0 deletions
diff --git a/arch/mips/lantiq/xway/dma.c b/arch/mips/lantiq/xway/dma.c new file mode 100644 index 000000000..34a116e84 --- /dev/null +++ b/arch/mips/lantiq/xway/dma.c @@ -0,0 +1,274 @@ +/* + * 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. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA. + * + * Copyright (C) 2011 John Crispin <blogic@openwrt.org> + */ + +#include <linux/init.h> +#include <linux/platform_device.h> +#include <linux/io.h> +#include <linux/dma-mapping.h> +#include <linux/module.h> +#include <linux/clk.h> +#include <linux/err.h> + +#include <lantiq_soc.h> +#include <xway_dma.h> + +#define LTQ_DMA_ID 0x08 +#define LTQ_DMA_CTRL 0x10 +#define LTQ_DMA_CPOLL 0x14 +#define LTQ_DMA_CS 0x18 +#define LTQ_DMA_CCTRL 0x1C +#define LTQ_DMA_CDBA 0x20 +#define LTQ_DMA_CDLEN 0x24 +#define LTQ_DMA_CIS 0x28 +#define LTQ_DMA_CIE 0x2C +#define LTQ_DMA_PS 0x40 +#define LTQ_DMA_PCTRL 0x44 +#define LTQ_DMA_IRNEN 0xf4 + +#define DMA_DESCPT BIT(3) /* descriptor complete irq */ +#define DMA_TX BIT(8) /* TX channel direction */ +#define DMA_CHAN_ON BIT(0) /* channel on / off bit */ +#define DMA_PDEN BIT(6) /* enable packet drop */ +#define DMA_CHAN_RST BIT(1) /* channel on / off bit */ +#define DMA_RESET BIT(0) /* channel on / off bit */ +#define DMA_IRQ_ACK 0x7e /* IRQ status register */ +#define DMA_POLL BIT(31) /* turn on channel polling */ +#define DMA_CLK_DIV4 BIT(6) /* polling clock divider */ +#define DMA_2W_BURST BIT(1) /* 2 word burst length */ +#define DMA_MAX_CHANNEL 20 /* the soc has 20 channels */ +#define DMA_ETOP_ENDIANNESS (0xf << 8) /* endianness swap etop channels */ +#define DMA_WEIGHT (BIT(17) | BIT(16)) /* default channel wheight */ + +#define ltq_dma_r32(x) ltq_r32(ltq_dma_membase + (x)) +#define ltq_dma_w32(x, y) ltq_w32(x, ltq_dma_membase + (y)) +#define ltq_dma_w32_mask(x, y, z) ltq_w32_mask(x, y, \ + ltq_dma_membase + (z)) + +static void __iomem *ltq_dma_membase; + +void +ltq_dma_enable_irq(struct ltq_dma_channel *ch) +{ + unsigned long flags; + + local_irq_save(flags); + ltq_dma_w32(ch->nr, LTQ_DMA_CS); + ltq_dma_w32_mask(0, 1 << ch->nr, LTQ_DMA_IRNEN); + local_irq_restore(flags); +} +EXPORT_SYMBOL_GPL(ltq_dma_enable_irq); + +void +ltq_dma_disable_irq(struct ltq_dma_channel *ch) +{ + unsigned long flags; + + local_irq_save(flags); + ltq_dma_w32(ch->nr, LTQ_DMA_CS); + ltq_dma_w32_mask(1 << ch->nr, 0, LTQ_DMA_IRNEN); + local_irq_restore(flags); +} +EXPORT_SYMBOL_GPL(ltq_dma_disable_irq); + +void +ltq_dma_ack_irq(struct ltq_dma_channel *ch) +{ + unsigned long flags; + + local_irq_save(flags); + ltq_dma_w32(ch->nr, LTQ_DMA_CS); + ltq_dma_w32(DMA_IRQ_ACK, LTQ_DMA_CIS); + local_irq_restore(flags); +} +EXPORT_SYMBOL_GPL(ltq_dma_ack_irq); + +void +ltq_dma_open(struct ltq_dma_channel *ch) +{ + unsigned long flag; + + local_irq_save(flag); + ltq_dma_w32(ch->nr, LTQ_DMA_CS); + ltq_dma_w32_mask(0, DMA_CHAN_ON, LTQ_DMA_CCTRL); + ltq_dma_enable_irq(ch); + local_irq_restore(flag); +} +EXPORT_SYMBOL_GPL(ltq_dma_open); + +void +ltq_dma_close(struct ltq_dma_channel *ch) +{ + unsigned long flag; + + local_irq_save(flag); + ltq_dma_w32(ch->nr, LTQ_DMA_CS); + ltq_dma_w32_mask(DMA_CHAN_ON, 0, LTQ_DMA_CCTRL); + ltq_dma_disable_irq(ch); + local_irq_restore(flag); +} +EXPORT_SYMBOL_GPL(ltq_dma_close); + +static void +ltq_dma_alloc(struct ltq_dma_channel *ch) +{ + unsigned long flags; + + ch->desc = 0; + ch->desc_base = dma_alloc_coherent(NULL, + LTQ_DESC_NUM * LTQ_DESC_SIZE, + &ch->phys, GFP_ATOMIC); + memset(ch->desc_base, 0, LTQ_DESC_NUM * LTQ_DESC_SIZE); + + local_irq_save(flags); + ltq_dma_w32(ch->nr, LTQ_DMA_CS); + ltq_dma_w32(ch->phys, LTQ_DMA_CDBA); + ltq_dma_w32(LTQ_DESC_NUM, LTQ_DMA_CDLEN); + ltq_dma_w32_mask(DMA_CHAN_ON, 0, LTQ_DMA_CCTRL); + wmb(); + ltq_dma_w32_mask(0, DMA_CHAN_RST, LTQ_DMA_CCTRL); + while (ltq_dma_r32(LTQ_DMA_CCTRL) & DMA_CHAN_RST) + ; + local_irq_restore(flags); +} + +void +ltq_dma_alloc_tx(struct ltq_dma_channel *ch) +{ + unsigned long flags; + + ltq_dma_alloc(ch); + + local_irq_save(flags); + ltq_dma_w32(DMA_DESCPT, LTQ_DMA_CIE); + ltq_dma_w32_mask(0, 1 << ch->nr, LTQ_DMA_IRNEN); + ltq_dma_w32(DMA_WEIGHT | DMA_TX, LTQ_DMA_CCTRL); + local_irq_restore(flags); +} +EXPORT_SYMBOL_GPL(ltq_dma_alloc_tx); + +void +ltq_dma_alloc_rx(struct ltq_dma_channel *ch) +{ + unsigned long flags; + + ltq_dma_alloc(ch); + + local_irq_save(flags); + ltq_dma_w32(DMA_DESCPT, LTQ_DMA_CIE); + ltq_dma_w32_mask(0, 1 << ch->nr, LTQ_DMA_IRNEN); + ltq_dma_w32(DMA_WEIGHT, LTQ_DMA_CCTRL); + local_irq_restore(flags); +} +EXPORT_SYMBOL_GPL(ltq_dma_alloc_rx); + +void +ltq_dma_free(struct ltq_dma_channel *ch) +{ + if (!ch->desc_base) + return; + ltq_dma_close(ch); + dma_free_coherent(NULL, LTQ_DESC_NUM * LTQ_DESC_SIZE, + ch->desc_base, ch->phys); +} +EXPORT_SYMBOL_GPL(ltq_dma_free); + +void +ltq_dma_init_port(int p) +{ + ltq_dma_w32(p, LTQ_DMA_PS); + switch (p) { + case DMA_PORT_ETOP: + /* + * Tell the DMA engine to swap the endianness of data frames and + * drop packets if the channel arbitration fails. + */ + ltq_dma_w32_mask(0, DMA_ETOP_ENDIANNESS | DMA_PDEN, + LTQ_DMA_PCTRL); + break; + + case DMA_PORT_DEU: + ltq_dma_w32((DMA_2W_BURST << 4) | (DMA_2W_BURST << 2), + LTQ_DMA_PCTRL); + break; + + default: + break; + } +} +EXPORT_SYMBOL_GPL(ltq_dma_init_port); + +static int +ltq_dma_init(struct platform_device *pdev) +{ + struct clk *clk; + struct resource *res; + unsigned id; + int i; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + ltq_dma_membase = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(ltq_dma_membase)) + panic("Failed to remap dma resource"); + + /* power up and reset the dma engine */ + clk = clk_get(&pdev->dev, NULL); + if (IS_ERR(clk)) + panic("Failed to get dma clock"); + + clk_enable(clk); + ltq_dma_w32_mask(0, DMA_RESET, LTQ_DMA_CTRL); + + /* disable all interrupts */ + ltq_dma_w32(0, LTQ_DMA_IRNEN); + + /* reset/configure each channel */ + for (i = 0; i < DMA_MAX_CHANNEL; i++) { + ltq_dma_w32(i, LTQ_DMA_CS); + ltq_dma_w32(DMA_CHAN_RST, LTQ_DMA_CCTRL); + ltq_dma_w32(DMA_POLL | DMA_CLK_DIV4, LTQ_DMA_CPOLL); + ltq_dma_w32_mask(DMA_CHAN_ON, 0, LTQ_DMA_CCTRL); + } + + id = ltq_dma_r32(LTQ_DMA_ID); + dev_info(&pdev->dev, + "Init done - hw rev: %X, ports: %d, channels: %d\n", + id & 0x1f, (id >> 16) & 0xf, id >> 20); + + return 0; +} + +static const struct of_device_id dma_match[] = { + { .compatible = "lantiq,dma-xway" }, + {}, +}; +MODULE_DEVICE_TABLE(of, dma_match); + +static struct platform_driver dma_driver = { + .probe = ltq_dma_init, + .driver = { + .name = "dma-xway", + .of_match_table = dma_match, + }, +}; + +int __init +dma_init(void) +{ + return platform_driver_register(&dma_driver); +} + +postcore_initcall(dma_init); |