--- /dev/null
+/* Altera TSE SGDMA and MSGDMA Linux driver
+ * Copyright (C) 2014 Altera Corporation. All rights reserved
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/list.h>
+#include "altera_utils.h"
+#include "altera_tse.h"
+#include "altera_sgdmahw.h"
+#include "altera_sgdma.h"
+
+static void sgdma_descrip(struct sgdma_descrip *desc,
+ struct sgdma_descrip *ndesc,
+ dma_addr_t ndesc_phys,
+ dma_addr_t raddr,
+ dma_addr_t waddr,
+ u16 length,
+ int generate_eop,
+ int rfixed,
+ int wfixed);
+
+static int sgdma_async_write(struct altera_tse_private *priv,
+ struct sgdma_descrip *desc);
+
+static int sgdma_async_read(struct altera_tse_private *priv);
+
+static dma_addr_t
+sgdma_txphysaddr(struct altera_tse_private *priv,
+ struct sgdma_descrip *desc);
+
+static dma_addr_t
+sgdma_rxphysaddr(struct altera_tse_private *priv,
+ struct sgdma_descrip *desc);
+
+static int sgdma_txbusy(struct altera_tse_private *priv);
+
+static int sgdma_rxbusy(struct altera_tse_private *priv);
+
+static void
+queue_tx(struct altera_tse_private *priv, struct tse_buffer *buffer);
+
+static void
+queue_rx(struct altera_tse_private *priv, struct tse_buffer *buffer);
+
+static struct tse_buffer *
+dequeue_tx(struct altera_tse_private *priv);
+
+static struct tse_buffer *
+dequeue_rx(struct altera_tse_private *priv);
+
+static struct tse_buffer *
+queue_rx_peekhead(struct altera_tse_private *priv);
+
+int sgdma_initialize(struct altera_tse_private *priv)
+{
+ priv->txctrlreg = SGDMA_CTRLREG_ILASTD;
+
+ priv->rxctrlreg = SGDMA_CTRLREG_IDESCRIP |
+ SGDMA_CTRLREG_ILASTD;
+
+ INIT_LIST_HEAD(&priv->txlisthd);
+ INIT_LIST_HEAD(&priv->rxlisthd);
+
+ priv->rxdescphys = (dma_addr_t) 0;
+ priv->txdescphys = (dma_addr_t) 0;
+
+ priv->rxdescphys = dma_map_single(priv->device, priv->rx_dma_desc,
+ priv->rxdescmem, DMA_BIDIRECTIONAL);
+
+ if (dma_mapping_error(priv->device, priv->rxdescphys)) {
+ sgdma_uninitialize(priv);
+ netdev_err(priv->dev, "error mapping rx descriptor memory\n");
+ return -EINVAL;
+ }
+
+ priv->txdescphys = dma_map_single(priv->device, priv->rx_dma_desc,
+ priv->rxdescmem, DMA_TO_DEVICE);
+
+ if (dma_mapping_error(priv->device, priv->txdescphys)) {
+ sgdma_uninitialize(priv);
+ netdev_err(priv->dev, "error mapping tx descriptor memory\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+void sgdma_uninitialize(struct altera_tse_private *priv)
+{
+ if (priv->rxdescphys)
+ dma_unmap_single(priv->device, priv->rxdescphys,
+ priv->rxdescmem, DMA_BIDIRECTIONAL);
+
+ if (priv->txdescphys)
+ dma_unmap_single(priv->device, priv->txdescphys,
+ priv->txdescmem, DMA_TO_DEVICE);
+}
+
+/* This function resets the SGDMA controller and clears the
+ * descriptor memory used for transmits and receives.
+ */
+void sgdma_reset(struct altera_tse_private *priv)
+{
+ u32 *ptxdescripmem = (u32 *)priv->tx_dma_desc;
+ u32 txdescriplen = priv->txdescmem;
+ u32 *prxdescripmem = (u32 *)priv->rx_dma_desc;
+ u32 rxdescriplen = priv->rxdescmem;
+ struct sgdma_csr *ptxsgdma = (struct sgdma_csr *)priv->tx_dma_csr;
+ struct sgdma_csr *prxsgdma = (struct sgdma_csr *)priv->rx_dma_csr;
+
+ /* Initialize descriptor memory to 0 */
+ memset(ptxdescripmem, 0, txdescriplen);
+ memset(prxdescripmem, 0, rxdescriplen);
+
+ iowrite32(SGDMA_CTRLREG_RESET, &ptxsgdma->control);
+ iowrite32(0, &ptxsgdma->control);
+
+ iowrite32(SGDMA_CTRLREG_RESET, &prxsgdma->control);
+ iowrite32(0, &prxsgdma->control);
+}
+
+void sgdma_enable_rxirq(struct altera_tse_private *priv)
+{
+ struct sgdma_csr *csr = (struct sgdma_csr *)priv->rx_dma_csr;
+ priv->rxctrlreg |= SGDMA_CTRLREG_INTEN;
+ tse_set_bit(&csr->control, SGDMA_CTRLREG_INTEN);
+}
+
+void sgdma_enable_txirq(struct altera_tse_private *priv)
+{
+ struct sgdma_csr *csr = (struct sgdma_csr *)priv->tx_dma_csr;
+ priv->txctrlreg |= SGDMA_CTRLREG_INTEN;
+ tse_set_bit(&csr->control, SGDMA_CTRLREG_INTEN);
+}
+
+/* for SGDMA, RX interrupts remain enabled after enabling */
+void sgdma_disable_rxirq(struct altera_tse_private *priv)
+{
+}
+
+/* for SGDMA, TX interrupts remain enabled after enabling */
+void sgdma_disable_txirq(struct altera_tse_private *priv)
+{
+}
+
+void sgdma_clear_rxirq(struct altera_tse_private *priv)
+{
+ struct sgdma_csr *csr = (struct sgdma_csr *)priv->rx_dma_csr;
+ tse_set_bit(&csr->control, SGDMA_CTRLREG_CLRINT);
+}
+
+void sgdma_clear_txirq(struct altera_tse_private *priv)
+{
+ struct sgdma_csr *csr = (struct sgdma_csr *)priv->tx_dma_csr;
+ tse_set_bit(&csr->control, SGDMA_CTRLREG_CLRINT);
+}
+
+/* transmits buffer through SGDMA. Returns number of buffers
+ * transmitted, 0 if not possible.
+ *
+ * tx_lock is held by the caller
+ */
+int sgdma_tx_buffer(struct altera_tse_private *priv, struct tse_buffer *buffer)
+{
+ int pktstx = 0;
+ struct sgdma_descrip *descbase =
+ (struct sgdma_descrip *)priv->tx_dma_desc;
+
+ struct sgdma_descrip *cdesc = &descbase[0];
+ struct sgdma_descrip *ndesc = &descbase[1];
+
+ /* wait 'til the tx sgdma is ready for the next transmit request */
+ if (sgdma_txbusy(priv))
+ return 0;
+
+ sgdma_descrip(cdesc, /* current descriptor */
+ ndesc, /* next descriptor */
+ sgdma_txphysaddr(priv, ndesc),
+ buffer->dma_addr, /* address of packet to xmit */
+ 0, /* write addr 0 for tx dma */
+ buffer->len, /* length of packet */
+ SGDMA_CONTROL_EOP, /* Generate EOP */
+ 0, /* read fixed */
+ SGDMA_CONTROL_WR_FIXED); /* Generate SOP */
+
+ pktstx = sgdma_async_write(priv, cdesc);
+
+ /* enqueue the request to the pending transmit queue */
+ queue_tx(priv, buffer);
+
+ return 1;
+}
+
+
+/* tx_lock held to protect access to queued tx list
+ */
+u32 sgdma_tx_completions(struct altera_tse_private *priv)
+{
+ u32 ready = 0;
+ struct sgdma_descrip *desc = (struct sgdma_descrip *)priv->tx_dma_desc;
+
+ if (!sgdma_txbusy(priv) &&
+ ((desc->control & SGDMA_CONTROL_HW_OWNED) == 0) &&
+ (dequeue_tx(priv))) {
+ ready = 1;
+ }
+
+ return ready;
+}
+
+int sgdma_add_rx_desc(struct altera_tse_private *priv,
+ struct tse_buffer *rxbuffer)
+{
+ queue_rx(priv, rxbuffer);
+ return sgdma_async_read(priv);
+}
+
+/* status is returned on upper 16 bits,
+ * length is returned in lower 16 bits
+ */
+u32 sgdma_rx_status(struct altera_tse_private *priv)
+{
+ struct sgdma_csr *csr = (struct sgdma_csr *)priv->rx_dma_csr;
+ struct sgdma_descrip *base = (struct sgdma_descrip *)priv->rx_dma_desc;
+ struct sgdma_descrip *desc = NULL;
+ int pktsrx;
+ unsigned int rxstatus = 0;
+ unsigned int pktlength = 0;
+ unsigned int pktstatus = 0;
+ struct tse_buffer *rxbuffer = NULL;
+
+ dma_sync_single_for_cpu(priv->device,
+ priv->rxdescphys,
+ priv->rxdescmem,
+ DMA_BIDIRECTIONAL);
+
+ desc = &base[0];
+ if ((ioread32(&csr->status) & SGDMA_STSREG_EOP) ||
+ (desc->status & SGDMA_STATUS_EOP)) {
+ pktlength = desc->bytes_xferred;
+ pktstatus = desc->status & 0x3f;
+ rxstatus = pktstatus;
+ rxstatus = rxstatus << 16;
+ rxstatus |= (pktlength & 0xffff);
+
+ desc->status = 0;
+
+ rxbuffer = dequeue_rx(priv);
+ if (rxbuffer == NULL)
+ netdev_err(priv->dev,
+ "sgdma rx and rx queue empty!\n");
+
+ /* kick the rx sgdma after reaping this descriptor */
+ pktsrx = sgdma_async_read(priv);
+ }
+
+ return rxstatus;
+}
+
+
+/* Private functions */
+static void sgdma_descrip(struct sgdma_descrip *desc,
+ struct sgdma_descrip *ndesc,
+ dma_addr_t ndesc_phys,
+ dma_addr_t raddr,
+ dma_addr_t waddr,
+ u16 length,
+ int generate_eop,
+ int rfixed,
+ int wfixed)
+{
+ /* Clear the next descriptor as not owned by hardware */
+ u32 ctrl = ndesc->control;
+ ctrl &= ~SGDMA_CONTROL_HW_OWNED;
+ ndesc->control = ctrl;
+
+ ctrl = 0;
+ ctrl = SGDMA_CONTROL_HW_OWNED;
+ ctrl |= generate_eop;
+ ctrl |= rfixed;
+ ctrl |= wfixed;
+
+ /* Channel is implicitly zero, initialized to 0 by default */
+
+ desc->raddr = raddr;
+ desc->waddr = waddr;
+ desc->next = lower_32_bits(ndesc_phys);
+ desc->control = ctrl;
+ desc->status = 0;
+ desc->rburst = 0;
+ desc->wburst = 0;
+ desc->bytes = length;
+ desc->bytes_xferred = 0;
+}
+
+/* If hardware is busy, don't restart async read.
+ * if status register is 0 - meaning initial state, restart async read,
+ * probably for the first time when populating a receive buffer.
+ * If read status indicate not busy and a status, restart the async
+ * DMA read.
+ */
+static int sgdma_async_read(struct altera_tse_private *priv)
+{
+ struct sgdma_csr *csr = (struct sgdma_csr *)priv->rx_dma_csr;
+ struct sgdma_descrip *descbase =
+ (struct sgdma_descrip *)priv->rx_dma_desc;
+
+ struct sgdma_descrip *cdesc = &descbase[0];
+ struct sgdma_descrip *ndesc = &descbase[1];
+
+ unsigned int sts = ioread32(&csr->status);
+ struct tse_buffer *rxbuffer = NULL;
+
+ if (!sgdma_rxbusy(priv)) {
+ rxbuffer = queue_rx_peekhead(priv);
+ if (rxbuffer == NULL)
+ return 0;
+
+ sgdma_descrip(cdesc, /* current descriptor */
+ ndesc, /* next descriptor */
+ sgdma_rxphysaddr(priv, ndesc),
+ 0, /* read addr 0 for rx dma */
+ rxbuffer->dma_addr, /* write addr for rx dma */
+ 0, /* read 'til EOP */
+ 0, /* EOP: NA for rx dma */
+ 0, /* read fixed: NA for rx dma */
+ 0); /* SOP: NA for rx DMA */
+
+ /* clear control and status */
+ iowrite32(0, &csr->control);
+
+ /* If statuc available, clear those bits */
+ if (sts & 0xf)
+ iowrite32(0xf, &csr->status);
+
+ dma_sync_single_for_device(priv->device,
+ priv->rxdescphys,
+ priv->rxdescmem,
+ DMA_BIDIRECTIONAL);
+
+ iowrite32(lower_32_bits(sgdma_rxphysaddr(priv, cdesc)),
+ &csr->next_descrip);
+
+ iowrite32((priv->rxctrlreg | SGDMA_CTRLREG_START),
+ &csr->control);
+
+ return 1;
+ }
+
+ return 0;
+}
+
+static int sgdma_async_write(struct altera_tse_private *priv,
+ struct sgdma_descrip *desc)
+{
+ struct sgdma_csr *csr = (struct sgdma_csr *)priv->tx_dma_csr;
+
+ if (sgdma_txbusy(priv))
+ return 0;
+
+ /* clear control and status */
+ iowrite32(0, &csr->control);
+ iowrite32(0x1f, &csr->status);
+
+ dma_sync_single_for_device(priv->device, priv->txdescphys,
+ priv->txdescmem, DMA_TO_DEVICE);
+
+ iowrite32(lower_32_bits(sgdma_txphysaddr(priv, desc)),
+ &csr->next_descrip);
+
+ iowrite32((priv->txctrlreg | SGDMA_CTRLREG_START),
+ &csr->control);
+
+ return 1;
+}
+
+static dma_addr_t
+sgdma_txphysaddr(struct altera_tse_private *priv,
+ struct sgdma_descrip *desc)
+{
+ dma_addr_t paddr = priv->txdescmem_busaddr;
+ dma_addr_t offs = (dma_addr_t)((dma_addr_t)desc -
+ (dma_addr_t)priv->tx_dma_desc);
+ return paddr + offs;
+}
+
+static dma_addr_t
+sgdma_rxphysaddr(struct altera_tse_private *priv,
+ struct sgdma_descrip *desc)
+{
+ dma_addr_t paddr = priv->rxdescmem_busaddr;
+ dma_addr_t offs = (dma_addr_t)((dma_addr_t)desc -
+ (dma_addr_t)priv->rx_dma_desc);
+ return paddr + offs;
+}
+
+#define list_remove_head(list, entry, type, member) \
+ do { \
+ entry = NULL; \
+ if (!list_empty(list)) { \
+ entry = list_entry((list)->next, type, member); \
+ list_del_init(&entry->member); \
+ } \
+ } while (0)
+
+#define list_peek_head(list, entry, type, member) \
+ do { \
+ entry = NULL; \
+ if (!list_empty(list)) { \
+ entry = list_entry((list)->next, type, member); \
+ } \
+ } while (0)
+
+/* adds a tse_buffer to the tail of a tx buffer list.
+ * assumes the caller is managing and holding a mutual exclusion
+ * primitive to avoid simultaneous pushes/pops to the list.
+ */
+static void
+queue_tx(struct altera_tse_private *priv, struct tse_buffer *buffer)
+{
+ list_add_tail(&buffer->lh, &priv->txlisthd);
+}
+
+
+/* adds a tse_buffer to the tail of a rx buffer list
+ * assumes the caller is managing and holding a mutual exclusion
+ * primitive to avoid simultaneous pushes/pops to the list.
+ */
+static void
+queue_rx(struct altera_tse_private *priv, struct tse_buffer *buffer)
+{
+ list_add_tail(&buffer->lh, &priv->rxlisthd);
+}
+
+/* dequeues a tse_buffer from the transmit buffer list, otherwise
+ * returns NULL if empty.
+ * assumes the caller is managing and holding a mutual exclusion
+ * primitive to avoid simultaneous pushes/pops to the list.
+ */
+static struct tse_buffer *
+dequeue_tx(struct altera_tse_private *priv)
+{
+ struct tse_buffer *buffer = NULL;
+ list_remove_head(&priv->txlisthd, buffer, struct tse_buffer, lh);
+ return buffer;
+}
+
+/* dequeues a tse_buffer from the receive buffer list, otherwise
+ * returns NULL if empty
+ * assumes the caller is managing and holding a mutual exclusion
+ * primitive to avoid simultaneous pushes/pops to the list.
+ */
+static struct tse_buffer *
+dequeue_rx(struct altera_tse_private *priv)
+{
+ struct tse_buffer *buffer = NULL;
+ list_remove_head(&priv->rxlisthd, buffer, struct tse_buffer, lh);
+ return buffer;
+}
+
+/* dequeues a tse_buffer from the receive buffer list, otherwise
+ * returns NULL if empty
+ * assumes the caller is managing and holding a mutual exclusion
+ * primitive to avoid simultaneous pushes/pops to the list while the
+ * head is being examined.
+ */
+static struct tse_buffer *
+queue_rx_peekhead(struct altera_tse_private *priv)
+{
+ struct tse_buffer *buffer = NULL;
+ list_peek_head(&priv->rxlisthd, buffer, struct tse_buffer, lh);
+ return buffer;
+}
+
+/* check and return rx sgdma status without polling
+ */
+static int sgdma_rxbusy(struct altera_tse_private *priv)
+{
+ struct sgdma_csr *csr = (struct sgdma_csr *)priv->rx_dma_csr;
+ return ioread32(&csr->status) & SGDMA_STSREG_BUSY;
+}
+
+/* waits for the tx sgdma to finish it's current operation, returns 0
+ * when it transitions to nonbusy, returns 1 if the operation times out
+ */
+static int sgdma_txbusy(struct altera_tse_private *priv)
+{
+ int delay = 0;
+ struct sgdma_csr *csr = (struct sgdma_csr *)priv->tx_dma_csr;
+
+ /* if DMA is busy, wait for current transactino to finish */
+ while ((ioread32(&csr->status) & SGDMA_STSREG_BUSY) && (delay++ < 100))
+ udelay(1);
+
+ if (ioread32(&csr->status) & SGDMA_STSREG_BUSY) {
+ netdev_err(priv->dev, "timeout waiting for tx dma\n");
+ return 1;
+ }
+ return 0;
+}
--- /dev/null
+/* Altera TSE SGDMA and MSGDMA Linux driver
+ * Copyright (C) 2014 Altera Corporation. All rights reserved
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __ALTERA_SGDMAHW_H__
+#define __ALTERA_SGDMAHW_H__
+
+/* SGDMA descriptor structure */
+struct sgdma_descrip {
+ unsigned int raddr; /* address of data to be read */
+ unsigned int pad1;
+ unsigned int waddr;
+ unsigned int pad2;
+ unsigned int next;
+ unsigned int pad3;
+ unsigned short bytes;
+ unsigned char rburst;
+ unsigned char wburst;
+ unsigned short bytes_xferred; /* 16 bits, bytes xferred */
+
+ /* bit 0: error
+ * bit 1: length error
+ * bit 2: crc error
+ * bit 3: truncated error
+ * bit 4: phy error
+ * bit 5: collision error
+ * bit 6: reserved
+ * bit 7: status eop for recv case
+ */
+ unsigned char status;
+
+ /* bit 0: eop
+ * bit 1: read_fixed
+ * bit 2: write fixed
+ * bits 3,4,5,6: Channel (always 0)
+ * bit 7: hardware owned
+ */
+ unsigned char control;
+} __packed;
+
+
+#define SGDMA_STATUS_ERR BIT(0)
+#define SGDMA_STATUS_LENGTH_ERR BIT(1)
+#define SGDMA_STATUS_CRC_ERR BIT(2)
+#define SGDMA_STATUS_TRUNC_ERR BIT(3)
+#define SGDMA_STATUS_PHY_ERR BIT(4)
+#define SGDMA_STATUS_COLL_ERR BIT(5)
+#define SGDMA_STATUS_EOP BIT(7)
+
+#define SGDMA_CONTROL_EOP BIT(0)
+#define SGDMA_CONTROL_RD_FIXED BIT(1)
+#define SGDMA_CONTROL_WR_FIXED BIT(2)
+
+/* Channel is always 0, so just zero initialize it */
+
+#define SGDMA_CONTROL_HW_OWNED BIT(7)
+
+/* SGDMA register space */
+struct sgdma_csr {
+ /* bit 0: error
+ * bit 1: eop
+ * bit 2: descriptor completed
+ * bit 3: chain completed
+ * bit 4: busy
+ * remainder reserved
+ */
+ u32 status;
+ u32 pad1[3];
+
+ /* bit 0: interrupt on error
+ * bit 1: interrupt on eop
+ * bit 2: interrupt after every descriptor
+ * bit 3: interrupt after last descrip in a chain
+ * bit 4: global interrupt enable
+ * bit 5: starts descriptor processing
+ * bit 6: stop core on dma error
+ * bit 7: interrupt on max descriptors
+ * bits 8-15: max descriptors to generate interrupt
+ * bit 16: Software reset
+ * bit 17: clears owned by hardware if 0, does not clear otherwise
+ * bit 18: enables descriptor polling mode
+ * bit 19-26: clocks before polling again
+ * bit 27-30: reserved
+ * bit 31: clear interrupt
+ */
+ u32 control;
+ u32 pad2[3];
+ u32 next_descrip;
+ u32 pad3[3];
+};
+
+
+#define SGDMA_STSREG_ERR BIT(0) /* Error */
+#define SGDMA_STSREG_EOP BIT(1) /* EOP */
+#define SGDMA_STSREG_DESCRIP BIT(2) /* Descriptor completed */
+#define SGDMA_STSREG_CHAIN BIT(3) /* Chain completed */
+#define SGDMA_STSREG_BUSY BIT(4) /* Controller busy */
+
+#define SGDMA_CTRLREG_IOE BIT(0) /* Interrupt on error */
+#define SGDMA_CTRLREG_IOEOP BIT(1) /* Interrupt on EOP */
+#define SGDMA_CTRLREG_IDESCRIP BIT(2) /* Interrupt after every descriptor */
+#define SGDMA_CTRLREG_ILASTD BIT(3) /* Interrupt after last descriptor */
+#define SGDMA_CTRLREG_INTEN BIT(4) /* Global Interrupt enable */
+#define SGDMA_CTRLREG_START BIT(5) /* starts descriptor processing */
+#define SGDMA_CTRLREG_STOPERR BIT(6) /* stop on dma error */
+#define SGDMA_CTRLREG_INTMAX BIT(7) /* Interrupt on max descriptors */
+#define SGDMA_CTRLREG_RESET BIT(16)/* Software reset */
+#define SGDMA_CTRLREG_COBHW BIT(17)/* Clears owned by hardware */
+#define SGDMA_CTRLREG_POLL BIT(18)/* enables descriptor polling mode */
+#define SGDMA_CTRLREG_CLRINT BIT(31)/* Clears interrupt */
+
+#endif /* __ALTERA_SGDMAHW_H__ */
projects / cascardo / linux.git / commitdiff