net: davinci_emac: separate out cpdma code

In addition to being embedded into the EMAC controller, the CPDMA hardware
block is used in TI's CPSW switch controller.  Fortunately, the programming
interface to this hardware block remains pretty nicely consistent across these
devices.

This patch adds a new CPDMA services layer, which can then be reused across
EMAC and CPSW drivers.
Signed-off-by: Cyril Chemparathy <cyril@ti.com>
Tested-by: Michael Williamson <michael.williamson@criticallink.com>
Tested-by: Caglar Akyuz <caglarakyuz@gmail.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

drivers/net/Kconfig

@@ -952,6 +952,7 @@ config TI_DAVINCI_EMAC
 	tristate "TI DaVinci EMAC Support"
 	depends on ARM && ( ARCH_DAVINCI || ARCH_OMAP3 )
 	select TI_DAVINCI_MDIO
+	select TI_DAVINCI_CPDMA
 	select PHYLIB
 	help
 	  This driver supports TI's DaVinci Ethernet .
@@ -969,6 +970,15 @@ config TI_DAVINCI_MDIO
 	  To compile this driver as a module, choose M here: the module
 	  will be called davinci_mdio.  This is recommended.
 
+config TI_DAVINCI_CPDMA
+	tristate "TI DaVinci CPDMA Support"
+	depends on ARM && ( ARCH_DAVINCI || ARCH_OMAP3 )
+	help
+	  This driver supports TI's DaVinci CPDMA dma engine.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called davinci_cpdma.  This is recommended.
+
 config DM9000
 	tristate "DM9000 support"
 	depends on ARM || BLACKFIN || MIPS

drivers/net/Makefile

@@ -8,6 +8,7 @@ obj-$(CONFIG_PHYLIB) += phy/
 
 obj-$(CONFIG_TI_DAVINCI_EMAC) += davinci_emac.o
 obj-$(CONFIG_TI_DAVINCI_MDIO) += davinci_mdio.o
+obj-$(CONFIG_TI_DAVINCI_CPDMA) += davinci_cpdma.o
 
 obj-$(CONFIG_E1000) += e1000/
 obj-$(CONFIG_E1000E) += e1000e/

drivers/net/davinci_cpdma.h

+/*
+ * Texas Instruments CPDMA Driver
+ *
+ * Copyright (C) 2010 Texas Instruments
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+#ifndef __DAVINCI_CPDMA_H__
+#define __DAVINCI_CPDMA_H__
+
+#define CPDMA_MAX_CHANNELS	BITS_PER_LONG
+
+#define tx_chan_num(chan)	(chan)
+#define rx_chan_num(chan)	((chan) + CPDMA_MAX_CHANNELS)
+#define is_rx_chan(chan)	((chan)->chan_num >= CPDMA_MAX_CHANNELS)
+#define is_tx_chan(chan)	(!is_rx_chan(chan))
+#define __chan_linear(chan_num)	((chan_num) & (CPDMA_MAX_CHANNELS - 1))
+#define chan_linear(chan)	__chan_linear((chan)->chan_num)
+
+struct cpdma_params {
+	struct device		*dev;
+	void __iomem		*dmaregs;
+	void __iomem		*txhdp, *rxhdp, *txcp, *rxcp;
+	void __iomem		*rxthresh, *rxfree;
+	int			num_chan;
+	bool			has_soft_reset;
+	int			min_packet_size;
+	u32			desc_mem_phys;
+	int			desc_mem_size;
+	int			desc_align;
+
+	/*
+	 * Some instances of embedded cpdma controllers have extra control and
+	 * status registers.  The following flag enables access to these
+	 * "extended" registers.
+	 */
+	bool			has_ext_regs;
+};
+
+struct cpdma_chan_stats {
+	u32			head_enqueue;
+	u32			tail_enqueue;
+	u32			pad_enqueue;
+	u32			misqueued;
+	u32			desc_alloc_fail;
+	u32			pad_alloc_fail;
+	u32			runt_receive_buff;
+	u32			runt_transmit_buff;
+	u32			empty_dequeue;
+	u32			busy_dequeue;
+	u32			good_dequeue;
+	u32			requeue;
+	u32			teardown_dequeue;
+};
+
+struct cpdma_ctlr;
+struct cpdma_chan;
+
+typedef void (*cpdma_handler_fn)(void *token, int len, int status);
+
+struct cpdma_ctlr *cpdma_ctlr_create(struct cpdma_params *params);
+int cpdma_ctlr_destroy(struct cpdma_ctlr *ctlr);
+int cpdma_ctlr_start(struct cpdma_ctlr *ctlr);
+int cpdma_ctlr_stop(struct cpdma_ctlr *ctlr);
+int cpdma_ctlr_dump(struct cpdma_ctlr *ctlr);
+
+struct cpdma_chan *cpdma_chan_create(struct cpdma_ctlr *ctlr, int chan_num,
+				     cpdma_handler_fn handler);
+int cpdma_chan_destroy(struct cpdma_chan *chan);
+int cpdma_chan_start(struct cpdma_chan *chan);
+int cpdma_chan_stop(struct cpdma_chan *chan);
+int cpdma_chan_dump(struct cpdma_chan *chan);
+
+int cpdma_chan_get_stats(struct cpdma_chan *chan,
+			 struct cpdma_chan_stats *stats);
+int cpdma_chan_submit(struct cpdma_chan *chan, void *token, void *data,
+		      int len, gfp_t gfp_mask);
+int cpdma_chan_process(struct cpdma_chan *chan, int quota);
+
+int cpdma_ctlr_int_ctrl(struct cpdma_ctlr *ctlr, bool enable);
+void cpdma_ctlr_eoi(struct cpdma_ctlr *ctlr);
+int cpdma_chan_int_ctrl(struct cpdma_chan *chan, bool enable);
+
+enum cpdma_control {
+	CPDMA_CMD_IDLE,			/* write-only */
+	CPDMA_COPY_ERROR_FRAMES,	/* read-write */
+	CPDMA_RX_OFF_LEN_UPDATE,	/* read-write */
+	CPDMA_RX_OWNERSHIP_FLIP,	/* read-write */
+	CPDMA_TX_PRIO_FIXED,		/* read-write */
+	CPDMA_STAT_IDLE,		/* read-only */
+	CPDMA_STAT_TX_ERR_CHAN,		/* read-only */
+	CPDMA_STAT_TX_ERR_CODE,		/* read-only */
+	CPDMA_STAT_RX_ERR_CHAN,		/* read-only */
+	CPDMA_STAT_RX_ERR_CODE,		/* read-only */
+	CPDMA_RX_BUFFER_OFFSET,		/* read-write */
+};
+
+int cpdma_control_get(struct cpdma_ctlr *ctlr, int control);
+int cpdma_control_set(struct cpdma_ctlr *ctlr, int control, int value);
+
+#endif