spi/pxa2xx: break out the private DMA API usage into a separate file

The PXA SPI driver uses PXA platform specific private DMA implementation
which does not work on non-PXA platforms. In order to use this driver on
other platforms we break out the private DMA implementation into a separate
file that gets compiled only when CONFIG_SPI_PXA2XX_PXADMA is set. The DMA
functions are stubbed out if there is no DMA implementation selected (i.e
we are building on non-PXA platform).

While we are there we can kill the dummy DMA bits in pxa2xx_spi.h as they
are not needed anymore for CE4100.

Once this is done we can add the generic DMA engine support to the driver
that allows usage of any DMA controller that implements DMA engine API.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Lu Cao <lucao@marvell.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

drivers/spi/Kconfig

@@ -297,6 +297,12 @@ config SPI_PPC4xx
 	help
 	  This selects a driver for the PPC4xx SPI Controller.
 
+config SPI_PXA2XX_PXADMA
+	bool "PXA2xx SSP legacy PXA DMA API support"
+	depends on SPI_PXA2XX && ARCH_PXA
+	help
+	  Enable PXA private legacy DMA API support.
+
 config SPI_PXA2XX
 	tristate "PXA2xx SSP SPI master"
 	depends on ARCH_PXA || PCI

drivers/spi/Makefile

@@ -47,7 +47,9 @@ obj-$(CONFIG_SPI_OMAP24XX)		+= spi-omap2-mcspi.o
 obj-$(CONFIG_SPI_ORION)			+= spi-orion.o
 obj-$(CONFIG_SPI_PL022)			+= spi-pl022.o
 obj-$(CONFIG_SPI_PPC4xx)		+= spi-ppc4xx.o
-obj-$(CONFIG_SPI_PXA2XX)		+= spi-pxa2xx.o
+spi-pxa2xx-platform-objs		:= spi-pxa2xx.o
+spi-pxa2xx-platform-$(CONFIG_SPI_PXA2XX_PXADMA)	+= spi-pxa2xx-pxadma.o
+obj-$(CONFIG_SPI_PXA2XX)		+= spi-pxa2xx-platform.o
 obj-$(CONFIG_SPI_PXA2XX_PCI)		+= spi-pxa2xx-pci.o
 obj-$(CONFIG_SPI_RSPI)			+= spi-rspi.o
 obj-$(CONFIG_SPI_S3C24XX)		+= spi-s3c24xx-hw.o

drivers/spi/spi-pxa2xx.h

+/*
+ * Copyright (C) 2005 Stephen Street / StreetFire Sound Labs
+ * Copyright (C) 2013, Intel Corporation
+ *
+ * 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.
+ */
+
+#ifndef SPI_PXA2XX_H
+#define SPI_PXA2XX_H
+
+#include <linux/errno.h>
+#include <linux/io.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/pxa2xx_ssp.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/pxa2xx_spi.h>
+
+struct driver_data {
+	/* Driver model hookup */
+	struct platform_device *pdev;
+
+	/* SSP Info */
+	struct ssp_device *ssp;
+
+	/* SPI framework hookup */
+	enum pxa_ssp_type ssp_type;
+	struct spi_master *master;
+
+	/* PXA hookup */
+	struct pxa2xx_spi_master *master_info;
+
+	/* PXA private DMA setup stuff */
+	int rx_channel;
+	int tx_channel;
+	u32 *null_dma_buf;
+
+	/* SSP register addresses */
+	void __iomem *ioaddr;
+	u32 ssdr_physical;
+
+	/* SSP masks*/
+	u32 dma_cr1;
+	u32 int_cr1;
+	u32 clear_sr;
+	u32 mask_sr;
+
+	/* Maximun clock rate */
+	unsigned long max_clk_rate;
+
+	/* Message Transfer pump */
+	struct tasklet_struct pump_transfers;
+
+	/* Current message transfer state info */
+	struct spi_message *cur_msg;
+	struct spi_transfer *cur_transfer;
+	struct chip_data *cur_chip;
+	size_t len;
+	void *tx;
+	void *tx_end;
+	void *rx;
+	void *rx_end;
+	int dma_mapped;
+	dma_addr_t rx_dma;
+	dma_addr_t tx_dma;
+	size_t rx_map_len;
+	size_t tx_map_len;
+	u8 n_bytes;
+	int (*write)(struct driver_data *drv_data);
+	int (*read)(struct driver_data *drv_data);
+	irqreturn_t (*transfer_handler)(struct driver_data *drv_data);
+	void (*cs_control)(u32 command);
+};
+
+struct chip_data {
+	u32 cr0;
+	u32 cr1;
+	u32 psp;
+	u32 timeout;
+	u8 n_bytes;
+	u32 dma_burst_size;
+	u32 threshold;
+	u32 dma_threshold;
+	u8 enable_dma;
+	u8 bits_per_word;
+	u32 speed_hz;
+	union {
+		int gpio_cs;
+		unsigned int frm;
+	};
+	int gpio_cs_inverted;
+	int (*write)(struct driver_data *drv_data);
+	int (*read)(struct driver_data *drv_data);
+	void (*cs_control)(u32 command);
+};
+
+#define DEFINE_SSP_REG(reg, off) \
+static inline u32 read_##reg(void const __iomem *p) \
+{ return __raw_readl(p + (off)); } \
+\
+static inline void write_##reg(u32 v, void __iomem *p) \
+{ __raw_writel(v, p + (off)); }
+
+DEFINE_SSP_REG(SSCR0, 0x00)
+DEFINE_SSP_REG(SSCR1, 0x04)
+DEFINE_SSP_REG(SSSR, 0x08)
+DEFINE_SSP_REG(SSITR, 0x0c)
+DEFINE_SSP_REG(SSDR, 0x10)
+DEFINE_SSP_REG(SSTO, 0x28)
+DEFINE_SSP_REG(SSPSP, 0x2c)
+
+#define START_STATE ((void *)0)
+#define RUNNING_STATE ((void *)1)
+#define DONE_STATE ((void *)2)
+#define ERROR_STATE ((void *)-1)
+
+#define MAX_DMA_LEN		8191
+#define IS_DMA_ALIGNED(x)	IS_ALIGNED((unsigned long)(x), DMA_ALIGNMENT)
+#define DMA_ALIGNMENT		8
+
+static inline int pxa25x_ssp_comp(struct driver_data *drv_data)
+{
+	if (drv_data->ssp_type == PXA25x_SSP)
+		return 1;
+	if (drv_data->ssp_type == CE4100_SSP)
+		return 1;
+	return 0;
+}
+
+static inline void write_SSSR_CS(struct driver_data *drv_data, u32 val)
+{
+	void __iomem *reg = drv_data->ioaddr;
+
+	if (drv_data->ssp_type == CE4100_SSP)
+		val |= read_SSSR(reg) & SSSR_ALT_FRM_MASK;
+
+	write_SSSR(val, reg);
+}
+
+extern int pxa2xx_spi_flush(struct driver_data *drv_data);
+extern void *pxa2xx_spi_next_transfer(struct driver_data *drv_data);
+
+#if defined(CONFIG_SPI_PXA2XX_PXADMA)
+extern bool pxa2xx_spi_dma_is_possible(size_t len);
+extern int pxa2xx_spi_map_dma_buffers(struct driver_data *drv_data);
+extern irqreturn_t pxa2xx_spi_dma_transfer(struct driver_data *drv_data);
+extern int pxa2xx_spi_dma_prepare(struct driver_data *drv_data, u32 dma_burst);
+extern void pxa2xx_spi_dma_start(struct driver_data *drv_data);
+extern int pxa2xx_spi_dma_setup(struct driver_data *drv_data);
+extern void pxa2xx_spi_dma_release(struct driver_data *drv_data);
+extern void pxa2xx_spi_dma_resume(struct driver_data *drv_data);
+extern int pxa2xx_spi_set_dma_burst_and_threshold(struct chip_data *chip,
+						  struct spi_device *spi,
+						  u8 bits_per_word,
+						  u32 *burst_code,
+						  u32 *threshold);
+#else
+static inline bool pxa2xx_spi_dma_is_possible(size_t len) { return false; }
+static inline int pxa2xx_spi_map_dma_buffers(struct driver_data *drv_data)
+{
+	return 0;
+}
+#define pxa2xx_spi_dma_transfer NULL
+static inline void pxa2xx_spi_dma_prepare(struct driver_data *drv_data,
+					  u32 dma_burst) {}
+static inline void pxa2xx_spi_dma_start(struct driver_data *drv_data) {}
+static inline int pxa2xx_spi_dma_setup(struct driver_data *drv_data)
+{
+	return 0;
+}
+static inline void pxa2xx_spi_dma_release(struct driver_data *drv_data) {}
+static inline void pxa2xx_spi_dma_resume(struct driver_data *drv_data) {}
+static inline int pxa2xx_spi_set_dma_burst_and_threshold(struct chip_data *chip,
+							 struct spi_device *spi,
+							 u8 bits_per_word,
+							 u32 *burst_code,
+							 u32 *threshold)
+{
+	return -ENODEV;
+}
+#endif
+
+#endif /* SPI_PXA2XX_H */

include/linux/spi/pxa2xx_spi.h

@@ -53,85 +53,5 @@ struct pxa2xx_spi_chip {
 
 extern void pxa2xx_set_spi_info(unsigned id, struct pxa2xx_spi_master *info);
 
-#else
-/*
- * This is the implemtation for CE4100 on x86. ARM defines them in mach/ or
- * plat/ include path.
- * The CE4100 does not provide DMA support. This bits are here to let the driver
- * compile and will never be used. Maybe we get DMA support at a later point in
- * time.
- */
-
-#define DCSR(n)         (n)
-#define DSADR(n)        (n)
-#define DTADR(n)        (n)
-#define DCMD(n)         (n)
-#define DRCMR(n)        (n)
-
-#define DCSR_RUN	(1 << 31)	/* Run Bit */
-#define DCSR_NODESC	(1 << 30)	/* No-Descriptor Fetch */
-#define DCSR_STOPIRQEN	(1 << 29)	/* Stop Interrupt Enable */
-#define DCSR_REQPEND	(1 << 8)	/* Request Pending (read-only) */
-#define DCSR_STOPSTATE	(1 << 3)	/* Stop State (read-only) */
-#define DCSR_ENDINTR	(1 << 2)	/* End Interrupt */
-#define DCSR_STARTINTR	(1 << 1)	/* Start Interrupt */
-#define DCSR_BUSERR	(1 << 0)	/* Bus Error Interrupt */
-
-#define DCSR_EORIRQEN	(1 << 28)	/* End of Receive Interrupt Enable */
-#define DCSR_EORJMPEN	(1 << 27)	/* Jump to next descriptor on EOR */
-#define DCSR_EORSTOPEN	(1 << 26)	/* STOP on an EOR */
-#define DCSR_SETCMPST	(1 << 25)	/* Set Descriptor Compare Status */
-#define DCSR_CLRCMPST	(1 << 24)	/* Clear Descriptor Compare Status */
-#define DCSR_CMPST	(1 << 10)	/* The Descriptor Compare Status */
-#define DCSR_EORINTR	(1 << 9)	/* The end of Receive */
-
-#define DRCMR_MAPVLD	(1 << 7)	/* Map Valid */
-#define DRCMR_CHLNUM	0x1f		/* mask for Channel Number */
-
-#define DDADR_DESCADDR	0xfffffff0	/* Address of next descriptor */
-#define DDADR_STOP	(1 << 0)	/* Stop */
-
-#define DCMD_INCSRCADDR	(1 << 31)	/* Source Address Increment Setting. */
-#define DCMD_INCTRGADDR	(1 << 30)	/* Target Address Increment Setting. */
-#define DCMD_FLOWSRC	(1 << 29)	/* Flow Control by the source. */
-#define DCMD_FLOWTRG	(1 << 28)	/* Flow Control by the target. */
-#define DCMD_STARTIRQEN	(1 << 22)	/* Start Interrupt Enable */
-#define DCMD_ENDIRQEN	(1 << 21)	/* End Interrupt Enable */
-#define DCMD_ENDIAN	(1 << 18)	/* Device Endian-ness. */
-#define DCMD_BURST8	(1 << 16)	/* 8 byte burst */
-#define DCMD_BURST16	(2 << 16)	/* 16 byte burst */
-#define DCMD_BURST32	(3 << 16)	/* 32 byte burst */
-#define DCMD_WIDTH1	(1 << 14)	/* 1 byte width */
-#define DCMD_WIDTH2	(2 << 14)	/* 2 byte width (HalfWord) */
-#define DCMD_WIDTH4	(3 << 14)	/* 4 byte width (Word) */
-#define DCMD_LENGTH	0x01fff		/* length mask (max = 8K - 1) */
-
-/*
- * Descriptor structure for PXA's DMA engine
- * Note: this structure must always be aligned to a 16-byte boundary.
- */
-
-typedef enum {
-	DMA_PRIO_HIGH = 0,
-	DMA_PRIO_MEDIUM = 1,
-	DMA_PRIO_LOW = 2
-} pxa_dma_prio;
-
-/*
- * DMA registration
- */
-
-static inline int pxa_request_dma(char *name,
-		pxa_dma_prio prio,
-		void (*irq_handler)(int, void *),
-		void *data)
-{
-	return -ENODEV;
-}
-
-static inline void pxa_free_dma(int dma_ch)
-{
-}
-
 #endif
 #endif