--- /dev/null
+/*
+ * 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);
Code Review / kvmfornfv.git / blobdiff