diff mbox

dw_spi: add DMA support

Message ID 20101022191049.8830.51496.stgit@localhost.localdomain (mailing list archive)
State Superseded, archived
Headers show

Commit Message

Alan Cox Oct. 22, 2010, 7:11 p.m. UTC
None
diff mbox

Patch

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 82e45cf..6e6a638 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -404,6 +404,10 @@  config SPI_DW_PCI
 	tristate "PCI interface driver for DW SPI core"
 	depends on SPI_DESIGNWARE && PCI
 
+config SPI_DW_MID_DMA
+	bool "DMA support for DW SPI controller on Intel Moorestown platform"
+	depends on SPI_DW_PCI && INTEL_MID_DMAC
+
 config SPI_DW_MMIO
 	tristate "Memory-mapped io interface driver for DW SPI core"
 	depends on SPI_DESIGNWARE && HAVE_CLK
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index b427c2e..4949370 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -17,7 +17,8 @@  obj-$(CONFIG_SPI_BUTTERFLY)		+= spi_butterfly.o
 obj-$(CONFIG_SPI_COLDFIRE_QSPI)		+= coldfire_qspi.o
 obj-$(CONFIG_SPI_DAVINCI)		+= davinci_spi.o
 obj-$(CONFIG_SPI_DESIGNWARE)		+= dw_spi.o
-obj-$(CONFIG_SPI_DW_PCI)		+= dw_spi_pci.o
+obj-$(CONFIG_SPI_DW_PCI)		+= dw_spi_midpci.o
+dw_spi_midpci-objs			:= dw_spi_pci.o dw_spi_mid.o
 obj-$(CONFIG_SPI_DW_MMIO)		+= dw_spi_mmio.o
 obj-$(CONFIG_SPI_EP93XX)		+= ep93xx_spi.o
 obj-$(CONFIG_SPI_GPIO)			+= spi_gpio.o
diff --git a/drivers/spi/dw_spi.c b/drivers/spi/dw_spi.c
index 9043931..69cc223 100644
--- a/drivers/spi/dw_spi.c
+++ b/drivers/spi/dw_spi.c
@@ -164,20 +164,23 @@  static inline void mrst_spi_debugfs_remove(struct dw_spi *dws)
 
 static void wait_till_not_busy(struct dw_spi *dws)
 {
-	unsigned long end = jiffies + 1 + usecs_to_jiffies(1000);
+	unsigned long end = jiffies + 1 + usecs_to_jiffies(5000);
 
 	while (time_before(jiffies, end)) {
 		if (!(dw_readw(dws, sr) & SR_BUSY))
 			return;
+		cpu_relax();
 	}
 	dev_err(&dws->master->dev,
-		"DW SPI: Status keeps busy for 1000us after a read/write!\n");
+		"DW SPI: Status keeps busy for 5000us after a read/write!\n");
 }
 
 static void flush(struct dw_spi *dws)
 {
-	while (dw_readw(dws, sr) & SR_RF_NOT_EMPT)
+	while (dw_readw(dws, sr) & SR_RF_NOT_EMPT) {
 		dw_readw(dws, dr);
+		cpu_relax();
+	}
 
 	wait_till_not_busy(dws);
 }
@@ -285,8 +288,10 @@  static void *next_transfer(struct dw_spi *dws)
  */
 static int map_dma_buffers(struct dw_spi *dws)
 {
-	if (!dws->cur_msg->is_dma_mapped || !dws->dma_inited
-		|| !dws->cur_chip->enable_dma)
+	if (!dws->cur_msg->is_dma_mapped
+		|| !dws->dma_inited
+		|| !dws->cur_chip->enable_dma
+		|| !dws->dma_ops)
 		return 0;
 
 	if (dws->cur_transfer->tx_dma)
@@ -338,7 +343,7 @@  static void int_error_stop(struct dw_spi *dws, const char *msg)
 	tasklet_schedule(&dws->pump_transfers);
 }
 
-static void transfer_complete(struct dw_spi *dws)
+void dw_spi_xfer_done(struct dw_spi *dws)
 {
 	/* Update total byte transfered return count actual bytes read */
 	dws->cur_msg->actual_length += dws->len;
@@ -353,6 +358,7 @@  static void transfer_complete(struct dw_spi *dws)
 	} else
 		tasklet_schedule(&dws->pump_transfers);
 }
+EXPORT_SYMBOL_GPL(dw_spi_xfer_done);
 
 static irqreturn_t interrupt_transfer(struct dw_spi *dws)
 {
@@ -384,7 +390,7 @@  static irqreturn_t interrupt_transfer(struct dw_spi *dws)
 		if (dws->tx_end > dws->tx)
 			spi_umask_intr(dws, SPI_INT_TXEI);
 		else
-			transfer_complete(dws);
+			dw_spi_xfer_done(dws);
 	}
 
 	return IRQ_HANDLED;
@@ -414,11 +420,7 @@  static void poll_transfer(struct dw_spi *dws)
 	while (dws->write(dws))
 		dws->read(dws);
 
-	transfer_complete(dws);
-}
-
-static void dma_transfer(struct dw_spi *dws, int cs_change)
-{
+	dw_spi_xfer_done(dws);
 }
 
 static void pump_transfers(unsigned long data)
@@ -600,7 +602,7 @@  static void pump_transfers(unsigned long data)
 	}
 
 	if (dws->dma_mapped)
-		dma_transfer(dws, cs_change);
+		dws->dma_ops->dma_transfer(dws, cs_change);
 
 	if (chip->poll_mode)
 		poll_transfer(dws);
@@ -896,11 +898,15 @@  int __devinit dw_spi_add_host(struct dw_spi *dws)
 	master->setup = dw_spi_setup;
 	master->transfer = dw_spi_transfer;
 
-	dws->dma_inited = 0;
-
 	/* Basic HW init */
 	spi_hw_init(dws);
 
+	if (dws->dma_ops && dws->dma_ops->dma_init) {
+		ret = dws->dma_ops->dma_init(dws);
+		if (ret)
+			goto err_diable_hw;
+	}
+
 	/* Initial and start queue */
 	ret = init_queue(dws);
 	if (ret) {
@@ -925,6 +931,8 @@  int __devinit dw_spi_add_host(struct dw_spi *dws)
 
 err_queue_alloc:
 	destroy_queue(dws);
+	if (dws->dma_ops && dws->dma_ops->dma_exit)
+		dws->dma_ops->dma_exit(dws);
 err_diable_hw:
 	spi_enable_chip(dws, 0);
 	free_irq(dws->irq, dws);
@@ -933,7 +941,7 @@  err_free_master:
 exit:
 	return ret;
 }
-EXPORT_SYMBOL(dw_spi_add_host);
+EXPORT_SYMBOL_GPL(dw_spi_add_host);
 
 void __devexit dw_spi_remove_host(struct dw_spi *dws)
 {
@@ -949,6 +957,8 @@  void __devexit dw_spi_remove_host(struct dw_spi *dws)
 		dev_err(&dws->master->dev, "dw_spi_remove: workqueue will not "
 			"complete, message memory not freed\n");
 
+	if (dws->dma_ops && dws->dma_ops->dma_exit)
+		dws->dma_ops->dma_exit(dws);
 	spi_enable_chip(dws, 0);
 	/* Disable clk */
 	spi_set_clk(dws, 0);
@@ -957,7 +967,7 @@  void __devexit dw_spi_remove_host(struct dw_spi *dws)
 	/* Disconnect from the SPI framework */
 	spi_unregister_master(dws->master);
 }
-EXPORT_SYMBOL(dw_spi_remove_host);
+EXPORT_SYMBOL_GPL(dw_spi_remove_host);
 
 int dw_spi_suspend_host(struct dw_spi *dws)
 {
@@ -970,7 +980,7 @@  int dw_spi_suspend_host(struct dw_spi *dws)
 	spi_set_clk(dws, 0);
 	return ret;
 }
-EXPORT_SYMBOL(dw_spi_suspend_host);
+EXPORT_SYMBOL_GPL(dw_spi_suspend_host);
 
 int dw_spi_resume_host(struct dw_spi *dws)
 {
@@ -982,7 +992,7 @@  int dw_spi_resume_host(struct dw_spi *dws)
 		dev_err(&dws->master->dev, "fail to start queue (%d)\n", ret);
 	return ret;
 }
-EXPORT_SYMBOL(dw_spi_resume_host);
+EXPORT_SYMBOL_GPL(dw_spi_resume_host);
 
 MODULE_AUTHOR("Feng Tang <feng.tang@intel.com>");
 MODULE_DESCRIPTION("Driver for DesignWare SPI controller core");
diff --git a/drivers/spi/dw_spi_mid.c b/drivers/spi/dw_spi_mid.c
new file mode 100644
index 0000000..f7b5450
--- /dev/null
+++ b/drivers/spi/dw_spi_mid.c
@@ -0,0 +1,243 @@ 
+/*
+ * dw_spi_mid.c - special handling for DW core on Intel MID platform
+ *
+ * Copyright (c) 2009, Intel Corporation.
+ *
+ * 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, write to the Free Software Foundation,
+ * Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <linux/slab.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/dw_spi.h>
+
+#ifdef CONFIG_SPI_DW_MID_DMA
+#include <linux/intel_mid_dma.h>
+#include <linux/pci.h>
+
+struct mid_dma {
+	struct intel_mid_dma_slave	dmas_tx;
+	struct intel_mid_dma_slave	dmas_rx;
+};
+
+static bool mid_spi_dma_chan_filter(struct dma_chan *chan, void *param)
+{
+	struct dw_spi *dws = (struct dw_spi *)param;
+	bool ret = false;
+
+	if (!dws->dmac)
+		goto out;
+
+	if (chan->device->dev == &dws->dmac->dev)
+		ret = true;
+
+out:
+	return ret;
+}
+
+static int mid_spi_dma_init(struct dw_spi *dws)
+{
+	struct mid_dma *dw_dma = dws->dma_priv;
+	struct intel_mid_dma_slave *rxs, *txs;
+	dma_cap_mask_t mask;
+
+	dws->txchan = NULL;
+	dws->rxchan = NULL;
+
+	/*get pci device for DMA*/
+	dws->dmac = pci_get_device(PCI_VENDOR_ID_INTEL, 0x813, NULL);
+
+	/* 1. Init rx channel */
+	rxs = &dw_dma->dmas_rx;
+
+	rxs->dirn = DMA_FROM_DEVICE;
+	rxs->hs_mode = LNW_DMA_HW_HS;
+	rxs->cfg_mode = LNW_DMA_PER_TO_MEM;
+	rxs->src_width = LNW_DMA_WIDTH_16BIT;
+	rxs->dst_width = LNW_DMA_WIDTH_32BIT;
+	rxs->src_msize = LNW_DMA_MSIZE_16;
+	rxs->dst_msize = LNW_DMA_MSIZE_16;
+
+	dma_cap_zero(mask);
+	dma_cap_set(DMA_MEMCPY, mask);
+	dma_cap_set(DMA_SLAVE, mask);
+
+	dws->rxchan = dma_request_channel(mask, mid_spi_dma_chan_filter, dws);
+	if (!dws->rxchan)
+		goto err_exit;
+	dws->rxchan->private = rxs;
+
+	/* 2. Init tx channel */
+	txs = &dw_dma->dmas_tx;
+
+	txs->dirn = DMA_TO_DEVICE;
+	txs->hs_mode = LNW_DMA_HW_HS;
+	txs->cfg_mode = LNW_DMA_MEM_TO_PER;
+	txs->src_width = LNW_DMA_WIDTH_32BIT;
+	txs->dst_width = LNW_DMA_WIDTH_16BIT;
+	txs->src_msize = LNW_DMA_MSIZE_16;
+	txs->dst_msize = LNW_DMA_MSIZE_16;
+
+	dma_cap_set(DMA_SLAVE, mask);
+	dma_cap_set(DMA_MEMCPY, mask);
+
+	dws->txchan = dma_request_channel(mask, mid_spi_dma_chan_filter, dws);
+	if (!dws->txchan)
+		goto free_rxchan;
+	dws->txchan->private = txs;
+
+	/* Set the dma done bit to 1 */
+	dws->dma_inited = 1;
+	dws->txdma_done = 1;
+	dws->rxdma_done = 1;
+
+	dws->tx_param = ((u64)(unsigned long)dws << 32)
+				| (unsigned long)(&dws->txdma_done);
+	dws->rx_param = ((u64)(unsigned long)dws << 32)
+				| (unsigned long)(&dws->rxdma_done);
+	return 0;
+
+free_rxchan:
+	dma_release_channel(dws->rxchan);
+err_exit:
+	return -1;
+
+}
+
+static void mid_spi_dma_exit(struct dw_spi *dws)
+{
+	dma_release_channel(dws->txchan);
+	dma_release_channel(dws->rxchan);
+}
+
+static void dw_spi_dma_done(void *arg)
+{
+	u64 *param = arg;
+	struct dw_spi *dws;
+	int *done;
+
+	dws = (struct dw_spi *)(unsigned long)(*param >> 32);
+	done = (int *)(unsigned long)(*param & 0xffffffff);
+
+	*done = 1;
+	/* wait till both tx/rx channels are done */
+	if (!dws->txdma_done || !dws->rxdma_done)
+		return;
+
+	dw_spi_xfer_done(dws);
+}
+
+static int mid_spi_dma_transfer(struct dw_spi *dws, int cs_change)
+{
+	struct dma_async_tx_descriptor *txdesc = NULL, *rxdesc = NULL;
+	struct dma_chan *txchan, *rxchan;
+	enum dma_ctrl_flags flag;
+	u16 dma_ctrl = 0;
+
+	/* 1. setup DMA related registers */
+	if (cs_change) {
+		spi_enable_chip(dws, 0);
+		dw_writew(dws, dmardlr, 0xf);
+		dw_writew(dws, dmatdlr, 0x10);
+		if (dws->tx_dma)
+			dma_ctrl |= 0x2;
+		if (dws->rx_dma)
+			dma_ctrl |= 0x1;
+		dw_writew(dws, dmacr, dma_ctrl);
+		spi_enable_chip(dws, 1);
+	}
+
+	if (dws->tx_dma)
+		dws->txdma_done = 0;
+	if (dws->rx_dma)
+		dws->rxdma_done = 0;
+
+	/* 2. start the TX dma transfer */
+	txchan = dws->txchan;
+	rxchan = dws->rxchan;
+
+	flag = DMA_PREP_INTERRUPT | DMA_CTRL_ACK;
+	if (dws->tx_dma) {
+		txdesc = txchan->device->device_prep_dma_memcpy(txchan,
+				dws->dma_addr, dws->tx_dma,
+				dws->len, flag);
+		txdesc->callback = dw_spi_dma_done;
+		txdesc->callback_param = &dws->tx_param;
+	}
+
+	/* 3. start the RX dma transfer */
+	if (dws->rx_dma) {
+		rxdesc = rxchan->device->device_prep_dma_memcpy(rxchan,
+				dws->rx_dma, dws->dma_addr,
+				dws->len, flag);
+		rxdesc->callback = dw_spi_dma_done;
+		rxdesc->callback_param = &dws->rx_param;
+	}
+
+	/* rx must be started before tx due to spi instinct */
+	if (rxdesc)
+		rxdesc->tx_submit(rxdesc);
+	if (txdesc)
+		txdesc->tx_submit(txdesc);
+
+	return 0;
+}
+
+static struct dw_spi_dma_ops mid_dma_ops = {
+	.dma_init	= mid_spi_dma_init,
+	.dma_exit	= mid_spi_dma_exit,
+	.dma_transfer	= mid_spi_dma_transfer,
+};
+#endif
+
+/* Some specific info for SPI0 controller on Moorestown */
+/* HW info for MRST CLk Control Unit, one 32b reg */
+#define MRST_SPI_CLK_BASE	100000000	/* 100m */
+#define MRST_CLK_SPI0_REG	0xff11d86c
+#define CLK_SPI_BDIV_OFFSET	0
+#define CLK_SPI_BDIV_MASK	0x00000007
+#define CLK_SPI_CDIV_OFFSET	9
+#define CLK_SPI_CDIV_MASK	0x00000e00
+#define CLK_SPI_CDIV_100M	0x0
+#define CLK_SPI_CDIV_50M	0x1
+#define CLK_SPI_CDIV_33M	0x2
+#define CLK_SPI_CDIV_25M	0x3
+#define CLK_SPI_DISABLE_OFFSET	8
+
+int dw_spi_mid_init(struct dw_spi *dws)
+{
+	u32 *clk_reg, clk_cdiv;
+
+	clk_reg = ioremap_nocache(MRST_CLK_SPI0_REG, 16);
+	if (!clk_reg)
+		return -ENOMEM;
+
+	/* get SPI controller operating freq info */
+	clk_cdiv  = ((*clk_reg) & CLK_SPI_CDIV_MASK) >> CLK_SPI_CDIV_OFFSET;
+	dws->max_freq = MRST_SPI_CLK_BASE / (clk_cdiv + 1);
+	iounmap(clk_reg);
+
+	dws->num_cs = 16;
+	dws->fifo_len = 40;	/* FIFO has 40 words buffer */
+
+#ifdef CONFIG_SPI_DW_MID_DMA
+	dws->dma_priv = kzalloc(sizeof(struct mid_dma), GFP_KERNEL);
+	if (!dws->dma_priv)
+		return -ENOMEM;
+	dws->dma_ops = &mid_dma_ops;
+#endif
+	return 0;
+}
+
diff --git a/drivers/spi/dw_spi_pci.c b/drivers/spi/dw_spi_pci.c
index 1f52755..076d1f8 100644
--- a/drivers/spi/dw_spi_pci.c
+++ b/drivers/spi/dw_spi_pci.c
@@ -1,5 +1,5 @@ 
 /*
- * mrst_spi_pci.c - PCI interface driver for DW SPI Core
+ * dw_spi_pci.c - PCI interface driver for DW SPI Core
  *
  * Copyright (c) 2009, Intel Corporation.
  *
@@ -26,8 +26,8 @@ 
 #define DRIVER_NAME "dw_spi_pci"
 
 struct dw_spi_pci {
-	struct pci_dev		*pdev;
-	struct dw_spi		dws;
+	struct pci_dev	*pdev;
+	struct dw_spi	dws;
 };
 
 static int __devinit spi_pci_probe(struct pci_dev *pdev,
@@ -72,9 +72,13 @@  static int __devinit spi_pci_probe(struct pci_dev *pdev,
 	dws->parent_dev = &pdev->dev;
 	dws->bus_num = 0;
 	dws->num_cs = 4;
-	dws->max_freq = 25000000;	/* for Moorestwon */
 	dws->irq = pdev->irq;
-	dws->fifo_len = 40;		/* FIFO has 40 words buffer */
+
+	if (pdev->device == 0x0800) {
+		ret = dw_spi_mid_init(dws);
+		if (ret)
+			goto err_unmap;
+	}
 
 	ret = dw_spi_add_host(dws);
 	if (ret)
diff --git a/include/linux/spi/dw_spi.h b/include/linux/spi/dw_spi.h
index c91302f..b2ecf9f 100644
--- a/include/linux/spi/dw_spi.h
+++ b/include/linux/spi/dw_spi.h
@@ -1,5 +1,6 @@ 
 #ifndef DW_SPI_HEADER_H
 #define DW_SPI_HEADER_H
+
 #include <linux/io.h>
 
 /* Bit fields in CTRLR0 */
@@ -82,6 +83,13 @@  struct dw_spi_reg {
 				though only low 16 bits matters */
 } __packed;
 
+struct dw_spi;
+struct dw_spi_dma_ops {
+	int (*dma_init)(struct dw_spi *dws);
+	void (*dma_exit)(struct dw_spi *dws);
+	int (*dma_transfer)(struct dw_spi *dws, int cs_change);
+};
+
 struct dw_spi {
 	struct spi_master	*master;
 	struct spi_device	*cur_dev;
@@ -143,6 +151,9 @@  struct dw_spi {
 	u64			rx_param;
 	struct device		*dma_dev;
 	dma_addr_t		dma_addr;
+	struct dw_spi_dma_ops	*dma_ops;
+	void			*dma_priv; /* platform relate info */
+	struct pci_dev		*dmac;
 
 	/* Bus interface info */
 	void			*priv;
@@ -216,4 +227,8 @@  extern int dw_spi_add_host(struct dw_spi *dws);
 extern void dw_spi_remove_host(struct dw_spi *dws);
 extern int dw_spi_suspend_host(struct dw_spi *dws);
 extern int dw_spi_resume_host(struct dw_spi *dws);
+extern void dw_spi_xfer_done(struct dw_spi *dws);
+
+/* platform related setup */
+extern int dw_spi_mid_init(struct dw_spi *dws); /* Intel MID platforms */
 #endif /* DW_SPI_HEADER_H */