[U-Boot] [RFC 02/14] dma: add bcm6348-iudma support

["Álvaro Fernández Rojas" <noltari@gmail.com>]

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
---
 drivers/dma/Kconfig         |   8 +
 drivers/dma/Makefile        |   1 +
 drivers/dma/bcm6348-iudma.c | 498 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 507 insertions(+)
 create mode 100644 drivers/dma/bcm6348-iudma.c

diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index 1b92c7789d..f58323f6c0 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -12,6 +12,14 @@ config DMA
 	  buses that is used to transfer data to and from memory.
 	  The uclass interface is defined in include/dma.h.
 
+config BCM6348_IUDMA
+	bool "BCM6348 IUDMA driver"
+	depends on ARCH_BMIPS
+	help
+	  Enable the BCM6348 IUDMA driver.
+	  This driver support data transfer from devices to
+	  memory and from memory to devices.
+
 config TI_EDMA3
 	bool "TI EDMA3 driver"
 	help
diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
index 39b78b2a3d..b2b4147349 100644
--- a/drivers/dma/Makefile
+++ b/drivers/dma/Makefile
@@ -9,6 +9,7 @@ obj-$(CONFIG_DMA) += dma-uclass.o
 
 obj-$(CONFIG_FSLDMAFEC) += MCD_tasksInit.o MCD_dmaApi.o MCD_tasks.o
 obj-$(CONFIG_APBH_DMA) += apbh_dma.o
+obj-$(CONFIG_BCM6348_IUDMA) += bcm6348-iudma.o
 obj-$(CONFIG_FSL_DMA) += fsl_dma.o
 obj-$(CONFIG_TI_KSNAV) += keystone_nav.o keystone_nav_cfg.o
 obj-$(CONFIG_TI_EDMA3) += ti-edma3.o
diff --git a/drivers/dma/bcm6348-iudma.c b/drivers/dma/bcm6348-iudma.c
new file mode 100644
index 0000000000..22d81cc990
--- /dev/null
+++ b/drivers/dma/bcm6348-iudma.c
@@ -0,0 +1,498 @@
+/*
+ * Copyright (C) 2018 Álvaro Fernández Rojas <noltari@gmail.com>
+ *
+ * Derived from linux/drivers/dma/bcm63xx-iudma.c:
+ *	Copyright (C) 2015 Simon Arlott <simon@fire.lp0.eu>
+ *
+ * Derived from linux/drivers/net/ethernet/broadcom/bcm63xx_enet.c:
+ *	Copyright (C) 2008 Maxime Bizon <mbizon@freebox.fr>
+ *
+ * Derived from bcm963xx_4.12L.06B_consumer/shared/opensource/include/bcm963xx/63268_map_part.h:
+ *	Copyright (C) 2000-2010 Broadcom Corporation
+ *
+ * Derived from bcm963xx_4.12L.06B_consumer/bcmdrivers/opensource/net/enet/impl4/bcmenet.c:
+ *	Copyright (C) 2010 Broadcom Corporation
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <clk.h>
+#include <dm.h>
+#include <dma-uclass.h>
+#include <memalign.h>
+#include <net.h>
+#include <reset.h>
+#include <asm/io.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+#define ALIGN_END_ADDR(type, ptr, size)	\
+	((unsigned long)(ptr) + roundup((size) * sizeof(type), \
+	 ARCH_DMA_MINALIGN))
+
+#define DMA_MAX_BURST_LENGTH	16
+
+/* DMA Channels */
+#define DMA_CHAN_FLOWC(x)		((x) >> 1)
+#define DMA_CHAN_FLOWC_MAX		8
+#define DMA_CHAN_MAX			16
+#define DMA_CHAN_SIZE			0x10
+#define DMA_CHAN_TOUT			500
+
+/* DMA Global Configuration register */
+#define DMA_CFG_REG			0x00
+#define DMA_CFG_ENABLE_SHIFT		0
+#define DMA_CFG_ENABLE_MASK		(1 << DMA_CFG_ENABLE_SHIFT)
+#define DMA_CFG_FLOWC_ENABLE(x)		BIT(DMA_CHAN_FLOWC(x) + 1)
+#define DMA_CFG_NCHANS_SHIFT		24
+#define DMA_CFG_NCHANS_MASK		(0xf << DMA_CFG_NCHANS_SHIFT)
+
+/* DMA Global Flow Control Threshold registers */
+#define DMA_FLOWC_THR_LO_REG(x)		(0x04 + DMA_CHAN_FLOWC(x) * 0x0c)
+#define DMA_FLOWC_THR_LO_SHIFT		0
+#define DMA_FLOWC_THR_LO_MASK		(5 << DMA_FLOWC_THR_LO_SHIFT)
+
+#define DMA_FLOWC_THR_HI_REG(x)		(0x08 + DMA_CHAN_FLOWC(x) * 0x0c)
+#define DMA_FLOWC_THR_HI_SHIFT		0
+#define DMA_FLOWC_THR_HI_MASK		(10 << DMA_FLOWC_THR_HI_SHIFT)
+
+/* DMA Global Flow Control Buffer Allocation registers */
+#define DMA_FLOWC_ALLOC_REG(x)		(0x0c + DMA_CHAN_FLOWC(x) * 0x0c)
+#define DMA_FLOWC_ALLOC_FORCE_SHIFT	31
+#define DMA_FLOWC_ALLOC_FORCE_MASK	(1 << DMA_FLOWC_ALLOC_FORCE_SHIFT)
+
+/* DMA Global Reset register */
+#define DMA_RST_REG			0x34
+#define DMA_RST_CHAN_SHIFT		0
+#define DMA_RST_CHAN_MASK(x)		(1 << x)
+
+/* DMA Channel Configuration register */
+#define DMAC_CFG_REG(x)			(DMA_CHAN_SIZE * (x) + 0x00)
+#define DMAC_CFG_ENABLE_SHIFT		0
+#define DMAC_CFG_ENABLE_MASK		(1 << DMAC_CFG_ENABLE_SHIFT)
+#define DMAC_CFG_PKT_HALT_SHIFT		1
+#define DMAC_CFG_PKT_HALT_MASK		(1 << DMAC_CFG_PKT_HALT_SHIFT)
+#define DMAC_CFG_BRST_HALT_SHIFT	2
+#define DMAC_CFG_BRST_HALT_MASK		(1 << DMAC_CFG_BRST_HALT_SHIFT)
+
+/* DMA Channel Interrupts registers */
+#define DMAC_IR_ST_REG(x)		(DMA_CHAN_SIZE * (x) + 0x04)
+#define DMAC_IR_EN_REG(x)		(DMA_CHAN_SIZE * (x) + 0x08)
+
+#define DMAC_IR_DONE_SHIFT		2
+#define DMAC_IR_DONE_MASK		(1 << DMAC_IR_DONE_SHIFT)
+
+/* DMA Channel Max Burst Length register */
+#define DMAC_BURST_REG(x)		(DMA_CHAN_SIZE * (x) + 0x0c)
+#define DMAC_BURST_MAX_SHIFT		0
+#define DMAC_BURST_MAX_MASK		(16 << DMAC_BURST_MAX_SHIFT)
+
+/* DMA SRAM Descriptor Ring Start register */
+#define DMAS_RSTART_REG(x)		(DMA_CHAN_SIZE * (x) + 0x00)
+
+/* DMA SRAM State/Bytes done/ring offset register */
+#define DMAS_STATE_DATA_REG(x)		(DMA_CHAN_SIZE * (x) + 0x04)
+
+/* DMA SRAM Buffer Descriptor status and length register */
+#define DMAS_DESC_LEN_STATUS_REG(x)	(DMA_CHAN_SIZE * (x) + 0x08)
+
+/* DMA SRAM Buffer Descriptor status and length register */
+#define DMAS_DESC_BASE_BUFPTR_REG(x)	(DMA_CHAN_SIZE * (x) + 0x0c)
+
+struct bcm6348_dma_desc {
+	uint16_t length;
+
+	uint16_t status;
+#define DMAD_ST_CRC_SHIFT	8
+#define DMAD_ST_CRC_MASK	(1 << DMAD_ST_CRC_SHIFT)
+#define DMAD_ST_WRAP_SHIFT	12
+#define DMAD_ST_WRAP_MASK	(1 << DMAD_ST_WRAP_SHIFT)
+#define DMAD_ST_SOP_SHIFT	13
+#define DMAD_ST_SOP_MASK	(1 << DMAD_ST_SOP_SHIFT)
+#define DMAD_ST_EOP_SHIFT	14
+#define DMAD_ST_EOP_MASK	(1 << DMAD_ST_EOP_SHIFT)
+#define DMAD_ST_OWN_SHIFT	15
+#define DMAD_ST_OWN_MASK	(1 << DMAD_ST_OWN_SHIFT)
+
+	uint32_t address;
+} __attribute__((aligned(1)));
+
+struct bcm6348_chan_priv {
+	void __iomem *dma_ring;
+	uint8_t dma_ring_size;
+	uint8_t desc_id;
+};
+
+struct bcm6348_iudma_priv {
+	void __iomem *base;
+	void __iomem *chan;
+	void __iomem *sram;
+	struct bcm6348_chan_priv **ch_priv;
+	uint8_t n_channels;
+};
+
+static bool bcm6348_iudma_chan_is_rx(uint8_t ch)
+{
+	return !(ch & 1);
+}
+
+static void bcm6348_iudma_chan_stop(struct bcm6348_iudma_priv *priv,
+				    uint8_t ch)
+{
+	unsigned int timeout = DMA_CHAN_TOUT;
+
+	/* disable dma channel interrupts */
+	writel_be(0, priv->chan + DMAC_IR_EN_REG(ch));
+
+	do {
+		uint32_t cfg, halt;
+
+		if (timeout > DMA_CHAN_TOUT / 2)
+			halt = DMAC_CFG_PKT_HALT_MASK;
+		else
+			halt = DMAC_CFG_BRST_HALT_MASK;
+
+		/* try to stop dma channel */
+		writel_be(halt, priv->chan + DMAC_CFG_REG(ch));
+		mb();
+
+		/* check if channel was stopped */
+		cfg = readl_be(priv->chan + DMAC_CFG_REG(ch));
+		if (!(cfg & DMAC_CFG_ENABLE_MASK))
+			break;
+
+		udelay(1);
+	} while (--timeout);
+
+	if (!timeout)
+		pr_err("unable to stop channel %u\n", ch);
+
+	/* reset dma channel */
+	setbits_be32(priv->base + DMA_RST_REG, DMA_RST_CHAN_MASK(ch));
+	clrbits_be32(priv->base + DMA_RST_REG, DMA_RST_CHAN_MASK(ch));
+}
+
+static int bcm6348_iudma_disable(struct dma *dma)
+{
+	struct bcm6348_iudma_priv *priv = dev_get_priv(dma->dev);
+
+	bcm6348_iudma_chan_stop(priv, dma->id);
+
+	if (bcm6348_iudma_chan_is_rx(dma->id))
+		writel_be(DMA_FLOWC_ALLOC_FORCE_MASK,
+			  DMA_FLOWC_ALLOC_REG(dma->id));
+
+	return 0;
+}
+
+static int bcm6348_iudma_enable(struct dma *dma)
+{
+	struct bcm6348_iudma_priv *priv = dev_get_priv(dma->dev);
+	struct bcm6348_chan_priv *ch_priv = priv->ch_priv[dma->id];
+	struct bcm6348_dma_desc *dma_desc;
+	uint8_t i;
+
+	/* init dma rings */
+	dma_desc = ch_priv->dma_ring;
+	for (i = 0; i < ch_priv->dma_ring_size; i++) {
+		if (bcm6348_iudma_chan_is_rx(dma->id)) {
+			dma_desc->status = DMAD_ST_OWN_MASK;
+			dma_desc->length = PKTSIZE_ALIGN;
+			dma_desc->address = virt_to_phys(net_rx_packets[i]);
+		} else {
+			dma_desc->status = 0;
+			dma_desc->length = 0;
+			dma_desc->address = 0;
+		}
+
+		if (i == ch_priv->dma_ring_size - 1)
+			dma_desc->status |= DMAD_ST_WRAP_MASK;
+
+		if (bcm6348_iudma_chan_is_rx(dma->id))
+			writel_be(1,
+				  priv->base + DMA_FLOWC_ALLOC_REG(dma->id));
+
+		dma_desc++;
+	}
+
+	/* init to first descriptor */
+	ch_priv->desc_id = 0;
+
+	/* force cache writeback */
+	flush_dcache_range((ulong)ch_priv->dma_ring,
+		ALIGN_END_ADDR(struct bcm6348_dma_desc, ch_priv->dma_ring,
+			       ch_priv->dma_ring_size));
+
+	/* clear sram */
+	writel_be(0, priv->sram + DMAS_STATE_DATA_REG(dma->id));
+	writel_be(0, priv->sram + DMAS_DESC_LEN_STATUS_REG(dma->id));
+	writel_be(0, priv->sram + DMAS_DESC_BASE_BUFPTR_REG(dma->id));
+
+	/* set dma ring start */
+	writel_be(virt_to_phys(ch_priv->dma_ring),
+		  priv->sram + DMAS_RSTART_REG(dma->id));
+
+	/* set flow control */
+	if (bcm6348_iudma_chan_is_rx(dma->id)) {
+		setbits_be32(priv->base + DMA_CFG_REG,
+			     DMA_CFG_FLOWC_ENABLE(dma->id));
+		writel_be(DMA_FLOWC_THR_LO_MASK,
+			  priv->base + DMA_FLOWC_THR_LO_REG(dma->id));
+		writel_be(DMA_FLOWC_THR_HI_MASK,
+			  priv->base + DMA_FLOWC_THR_HI_REG(dma->id));
+	}
+
+	/* set dma max burst */
+	writel_be(DMA_MAX_BURST_LENGTH, priv->chan + DMAC_BURST_REG(dma->id));
+
+	/* clear interrupts */
+	writel_be(DMAC_IR_DONE_MASK, priv->chan + DMAC_IR_ST_REG(dma->id));
+	writel_be(0, priv->chan + DMAC_IR_EN_REG(dma->id));
+
+	setbits_be32(priv->chan + DMAC_CFG_REG(dma->id), DMAC_CFG_ENABLE_MASK);
+
+	return 0;
+}
+
+static int bcm6348_iudma_request(struct dma *dma)
+{
+	struct bcm6348_iudma_priv *priv = dev_get_priv(dma->dev);
+	struct bcm6348_chan_priv *ch_priv;
+
+	/* check if channel is valid */
+	if (dma->id >= priv->n_channels)
+		return -ENODEV;
+
+	/* alloc channel private data */
+	priv->ch_priv[dma->id] = calloc(1, sizeof(struct bcm6348_chan_priv));
+	if (!priv->ch_priv[dma->id])
+		return -ENOMEM;
+	ch_priv = priv->ch_priv[dma->id];
+
+	/* alloc dma ring */
+	if (bcm6348_iudma_chan_is_rx(dma->id))
+		ch_priv->dma_ring_size = PKTBUFSRX;
+	else
+		ch_priv->dma_ring_size = 1;
+	ch_priv->dma_ring =
+		malloc_cache_aligned(sizeof(struct bcm6348_dma_desc) *
+				     ch_priv->dma_ring_size);
+	if (!ch_priv->dma_ring)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static int bcm6348_iudma_receive(struct dma *dma, void **dst)
+{
+	struct bcm6348_iudma_priv *priv = dev_get_priv(dma->dev);
+	struct bcm6348_chan_priv *ch_priv = priv->ch_priv[dma->id];
+	struct bcm6348_dma_desc *dma_desc;
+	void __iomem *dma_buff;
+	uint16_t status;
+	int ret;
+
+	/* get dma ring descriptor address */
+	dma_desc = ch_priv->dma_ring;
+	dma_desc += ch_priv->desc_id;
+
+	/* invalidate cache data */
+	invalidate_dcache_range((ulong)dma_desc,
+		ALIGN_END_ADDR(struct bcm6348_dma_desc, dma_desc, 1));
+
+	/* check dma own */
+	if (dma_desc->status & DMAD_ST_OWN_MASK)
+		return 0;
+
+	/* check dma end */
+	if (!(dma_desc->status & DMAD_ST_EOP_MASK))
+		return -EINVAL;
+
+	/* get dma buff descriptor address */
+	dma_buff = phys_to_virt(dma_desc->address);
+
+	/* invalidate cache data */
+	invalidate_dcache_range((ulong)dma_buff,
+				(ulong)(dma_buff + PKTSIZE_ALIGN));
+
+	/* get dma data */
+	*dst = dma_buff;
+	ret = dma_desc->length;
+
+	/* reinit dma descriptor */
+	status = dma_desc->status & DMAD_ST_WRAP_MASK;
+	status |= DMAD_ST_OWN_MASK;
+
+	dma_desc->length = PKTSIZE_ALIGN;
+	dma_desc->status = status;
+
+	/* flush cache */
+	flush_dcache_range((ulong)dma_desc,
+		ALIGN_END_ADDR(struct bcm6348_dma_desc, dma_desc, 1));
+
+	/* set flow control buffer alloc */
+	writel_be(1, priv->base + DMA_FLOWC_ALLOC_REG(dma->id));
+
+	/* enable dma */
+	setbits_be32(priv->chan + DMAC_CFG_REG(dma->id), DMAC_CFG_ENABLE_MASK);
+
+	/* set interrupt */
+	writel_be(DMAC_IR_DONE_MASK, priv->chan + DMAC_IR_EN_REG(dma->id));
+
+	/* increment dma descriptor */
+	ch_priv->desc_id = (ch_priv->desc_id + 1) % ch_priv->dma_ring_size;
+
+	return ret - 4;
+}
+
+static int bcm6348_iudma_send(struct dma *dma, void *src, size_t len)
+{
+	struct bcm6348_iudma_priv *priv = dev_get_priv(dma->dev);
+	struct bcm6348_chan_priv *ch_priv = priv->ch_priv[dma->id];
+	struct bcm6348_dma_desc *dma_desc;
+	uint16_t val;
+
+	/* get dma ring descriptor address */
+	dma_desc = ch_priv->dma_ring;
+	dma_desc += ch_priv->desc_id;
+
+	dma_desc->address = virt_to_phys(src);
+
+	/* config dma descriptor */
+	val = (DMAD_ST_OWN_MASK |
+	       DMAD_ST_EOP_MASK |
+	       DMAD_ST_CRC_MASK |
+	       DMAD_ST_SOP_MASK);
+	if (ch_priv->desc_id == ch_priv->dma_ring_size - 1)
+		val |= DMAD_ST_WRAP_MASK;
+
+	dma_desc->length = len;
+	dma_desc->status = val;
+
+	/* flush cache */
+	flush_dcache_range((ulong)src, (ulong)src + PKTSIZE_ALIGN);
+
+	/* flush cache */
+	flush_dcache_range((ulong)dma_desc,
+		ALIGN_END_ADDR(struct bcm6348_dma_desc, dma_desc, 1));
+
+	/* enable dma */
+	setbits_be32(priv->chan + DMAC_CFG_REG(dma->id), DMAC_CFG_ENABLE_MASK);
+
+	/* set interrupt */
+	writel_be(DMAC_IR_DONE_MASK, priv->chan + DMAC_IR_EN_REG(dma->id));
+
+	/* poll dma status */
+	do {
+		/* invalidate cache */
+		invalidate_dcache_range((ulong)dma_desc,
+			ALIGN_END_ADDR(struct bcm6348_dma_desc, dma_desc, 1));
+
+		if (!(dma_desc->status & DMAD_ST_OWN_MASK))
+			break;
+	} while(1);
+
+	/* increment dma descriptor */
+	ch_priv->desc_id = (ch_priv->desc_id + 1) % ch_priv->dma_ring_size;
+
+	return 0;
+}
+
+static const struct dma_ops bcm6348_iudma_ops = {
+	.disable = bcm6348_iudma_disable,
+	.enable = bcm6348_iudma_enable,
+	.request = bcm6348_iudma_request,
+	.receive = bcm6348_iudma_receive,
+	.send = bcm6348_iudma_send,
+};
+
+static const struct udevice_id bcm6348_iudma_ids[] = {
+	{ .compatible = "brcm,bcm6348-iudma", },
+	{ /* sentinel */ }
+};
+
+static int bcm6348_iudma_probe(struct udevice *dev)
+{
+	struct bcm6348_iudma_priv *priv = dev_get_priv(dev);
+	fdt_addr_t addr;
+	uint8_t ch;
+	int i;
+
+	/* try to enable clocks */
+	for (i = 0; ; i++) {
+		struct clk clk;
+		int ret;
+
+		ret = clk_get_by_index(dev, i, &clk);
+		if (ret < 0)
+			break;
+		if (clk_enable(&clk))
+			pr_err("failed to enable clock %d\n", i);
+		clk_free(&clk);
+	}
+
+	/* try to perform resets */
+	for (i = 0; ; i++) {
+		struct reset_ctl reset;
+		int ret;
+
+		ret = reset_get_by_index(dev, i, &reset);
+		if (ret < 0)
+			break;
+		if (reset_deassert(&reset))
+			pr_err("failed to deassert reset %d\n", i);
+		reset_free(&reset);
+	}
+
+	/* dma global base address */
+	addr = devfdt_get_addr_name(dev, "dma");
+	if (addr == FDT_ADDR_T_NONE)
+		return -EINVAL;
+	priv->base = ioremap(addr, 0);
+
+	/* dma channels base address */
+	addr = devfdt_get_addr_name(dev, "dma-channels");
+	if (addr == FDT_ADDR_T_NONE)
+		return -EINVAL;
+	priv->chan = ioremap(addr, 0);
+
+	/* dma sram base address */
+	addr = devfdt_get_addr_name(dev, "dma-sram");
+	if (addr == FDT_ADDR_T_NONE)
+		return -EINVAL;
+	priv->sram = ioremap(addr, 0);
+
+	/* disable dma controller */
+	clrbits_be32(priv->base + DMA_CFG_REG, DMA_CFG_ENABLE_MASK);
+
+	/* get number of channels */
+	priv->n_channels = fdtdec_get_uint(gd->fdt_blob, dev_of_offset(dev),
+					   "dma-channels", 8);
+	if (priv->n_channels > DMA_CHAN_MAX)
+		return -EINVAL;
+
+	/* alloc channel private data pointers */
+	priv->ch_priv = calloc(priv->n_channels,
+			       sizeof(struct bcm6348_chan_priv*));
+	if (!priv->ch_priv)
+		return -ENOMEM;
+
+	/* stop dma channels */
+	for (ch = 0; ch < priv->n_channels; ch++)
+		bcm6348_iudma_chan_stop(priv, ch);
+
+	/* enable dma controller */
+	setbits_be32(priv->base + DMA_CFG_REG, DMA_CFG_ENABLE_MASK);
+
+	return 0;
+}
+
+U_BOOT_DRIVER(bcm6348_iudma) = {
+	.name = "bcm6348_iudma",
+	.id = UCLASS_DMA,
+	.of_match = bcm6348_iudma_ids,
+	.ops = &bcm6348_iudma_ops,
+	.priv_auto_alloc_size = sizeof(struct bcm6348_iudma_priv),
+	.probe = bcm6348_iudma_probe,
+};
-- 
2.11.0