This patch adds support for the DMA engine found inside the XWAY family of
SoCs. The engine has 5 ports and 20 channels.
Signed-off-by: John Crispin <blogic@xxxxxxxxxxx>
Signed-off-by: Ralph Hempel <ralph.hempel@xxxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxx
---
Changes in V2
* use spinlocks
Changes in V3
* dma is not a platform device
.../mips/include/asm/mach-lantiq/xway/lantiq_soc.h | 3 +-
arch/mips/include/asm/mach-lantiq/xway/xway_dma.h | 60 +++++
arch/mips/lantiq/xway/Makefile | 2 +-
arch/mips/lantiq/xway/dma.c | 253 ++++++++++++++++++++
4 files changed, 316 insertions(+), 2 deletions(-)
create mode 100644 arch/mips/include/asm/mach-lantiq/xway/xway_dma.h
create mode 100644 arch/mips/lantiq/xway/dma.c
diff --git a/arch/mips/include/asm/mach-lantiq/xway/lantiq_soc.h b/arch/mips/include/asm/mach-lantiq/xway/lantiq_soc.h
index 343e82c..4827afb 100644
--- a/arch/mips/include/asm/mach-lantiq/xway/lantiq_soc.h
+++ b/arch/mips/include/asm/mach-lantiq/xway/lantiq_soc.h
@@ -86,7 +86,8 @@
#define LTQ_PPE32_SIZE 0x40000
/* DMA */
-#define LTQ_DMA_BASE_ADDR 0xBE104100
+#define LTQ_DMA_BASE_ADDR 0x1E104100
+#define LTQ_DMA_SIZE 0x800
/* PCI */
#define PCI_CR_BASE_ADDR 0x1E105400
diff --git a/arch/mips/include/asm/mach-lantiq/xway/xway_dma.h b/arch/mips/include/asm/mach-lantiq/xway/xway_dma.h
new file mode 100644
index 0000000..872943a
--- /dev/null
+++ b/arch/mips/include/asm/mach-lantiq/xway/xway_dma.h
@@ -0,0 +1,60 @@
+/*
+ * 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@xxxxxxxxxxx>
+ */
+
+#ifndef LTQ_DMA_H__
+#define LTQ_DMA_H__
+
+#define LTQ_DESC_SIZE 0x08 /* each descriptor is 64bit */
+#define LTQ_DESC_NUM 0x40 /* 64 descriptors / channel */
+
+#define LTQ_DMA_OWN BIT(31) /* owner bit */
+#define LTQ_DMA_C BIT(30) /* complete bit */
+#define LTQ_DMA_SOP BIT(29) /* start of packet */
+#define LTQ_DMA_EOP BIT(28) /* end of packet */
+#define LTQ_DMA_TX_OFFSET(x) ((x & 0x1f) << 23) /* data bytes offset */
+#define LTQ_DMA_RX_OFFSET(x) ((x & 0x7) << 23) /* data bytes offset */
+#define LTQ_DMA_SIZE_MASK (0xffff) /* the size field is 16 bit */
+
+struct ltq_dma_desc {
+ u32 ctl;
+ u32 addr;
+};
+
+struct ltq_dma_channel {
+ int nr; /* the channel number */
+ int irq; /* the mapped irq */
+ int desc; /* the current descriptor */
+ struct ltq_dma_desc *desc_base; /* the descriptor base */
+ int phys; /* physical addr */
+};
+
+enum {
+ DMA_PORT_ETOP = 0,
+ DMA_PORT_DEU,
+};
+
+extern void ltq_dma_enable_irq(struct ltq_dma_channel *ch);
+extern void ltq_dma_disable_irq(struct ltq_dma_channel *ch);
+extern void ltq_dma_ack_irq(struct ltq_dma_channel *ch);
+extern void ltq_dma_open(struct ltq_dma_channel *ch);
+extern void ltq_dma_close(struct ltq_dma_channel *ch);
+extern void ltq_dma_alloc_tx(struct ltq_dma_channel *ch);
+extern void ltq_dma_alloc_rx(struct ltq_dma_channel *ch);
+extern void ltq_dma_free(struct ltq_dma_channel *ch);
+extern void ltq_dma_init_port(int p);
+
+#endif
diff --git a/arch/mips/lantiq/xway/Makefile b/arch/mips/lantiq/xway/Makefile
index a021def..d88a3e8 100644
--- a/arch/mips/lantiq/xway/Makefile
+++ b/arch/mips/lantiq/xway/Makefile
@@ -1,4 +1,4 @@
-obj-y := pmu.o ebu.o reset.o gpio.o gpio_stp.o gpio_ebu.o devices.o
+obj-y := pmu.o ebu.o reset.o gpio.o gpio_stp.o gpio_ebu.o devices.o dma.o
obj-$(CONFIG_SOC_XWAY) += clk-xway.o prom-xway.o
obj-$(CONFIG_SOC_AMAZON_SE) += clk-ase.o prom-ase.o
diff --git a/arch/mips/lantiq/xway/dma.c b/arch/mips/lantiq/xway/dma.c
new file mode 100644
index 0000000..4278a45
--- /dev/null
+++ b/arch/mips/lantiq/xway/dma.c
@@ -0,0 +1,253 @@
+/*
+ * 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@xxxxxxxxxxx>
+ */
+
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/dma-mapping.h>
+
+#include <lantiq_soc.h>
+#include <xway_dma.h>
+
+#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_ENDIANESS (0xf << 8) /* endianess 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 struct resource ltq_dma_resource = {
+ .name = "dma",
+ .start = LTQ_DMA_BASE_ADDR,
+ .end = LTQ_DMA_BASE_ADDR + LTQ_DMA_SIZE - 1,
+ .flags = IORESOURCE_MEM,
+};
+
+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 endianess of data frames and
+ * drop packets if the channel arbitration fails.
+ */
+ ltq_dma_w32_mask(0, DMA_ETOP_ENDIANESS | 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);
+
+int __init
+ltq_dma_init(void)
+{
+ int i;
+
+ /* insert and request the memory region */
+ if (insert_resource(&iomem_resource, <q_dma_resource) < 0)
+ panic("Failed to insert dma memory\n");
+
+ if (request_mem_region(ltq_dma_resource.start,
+ resource_size(<q_dma_resource), "dma") < 0)
+ panic("Failed to request dma memory\n");
+
+ /* remap dma register range */
+ ltq_dma_membase = ioremap_nocache(ltq_dma_resource.start,
+ resource_size(<q_dma_resource));
+ if (!ltq_dma_membase)
+ panic("Failed to remap dma memory\n");
+
+ /* power up and reset the dma engine */
+ ltq_pmu_enable(PMU_DMA);
+ 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);
+ }
+ return 0;
+}
+
+postcore_initcall(ltq_dma_init);
--
1.7.2.3
