remarkable-linux/drivers/spi/spi-dw.h
Michael van der Westhuizen c4fe57f762 spi: dw: Allow interface drivers to limit data I/O to word sizes
The commit dd11444327 ("spi: dw-spi: Convert 16bit accesses to 32bit
accesses") changed all 16bit accesses in the DW_apb_ssi driver to 32bit.
This, unfortunately, breaks data register access on picoXcell, where the
DW IP needs data register accesses to be word accesses (all other
accesses appear to be OK).

This change introduces a new master variable to allow interface drivers
to specify that 16bit data transfer I/O is required.  This change also
introduces the ability to set this variable via device tree bindings in
the MMIO interface driver.  Both the core and the MMIO interface driver
default to the current 32bit behaviour.

Before this change, on a picoXcell pc3x3:
 spi_master spi32766: interrupt_transfer: fifo overrun/underrun
 m25p80 spi32766.0: error -5 reading 9f
 m25p80: probe of spi32766.0 failed with error -5

After this change:
 m25p80 spi32766.0: m25p40 (512 Kbytes)

Fixes: dd11444327 ("spi: dw-spi: Convert 16bit accesses to 32bit accesses")
Signed-off-by: Michael van der Westhuizen <michael@smart-africa.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-08-21 10:25:28 -07:00

248 lines
6 KiB
C

#ifndef DW_SPI_HEADER_H
#define DW_SPI_HEADER_H
#include <linux/io.h>
#include <linux/scatterlist.h>
#include <linux/gpio.h>
/* Register offsets */
#define DW_SPI_CTRL0 0x00
#define DW_SPI_CTRL1 0x04
#define DW_SPI_SSIENR 0x08
#define DW_SPI_MWCR 0x0c
#define DW_SPI_SER 0x10
#define DW_SPI_BAUDR 0x14
#define DW_SPI_TXFLTR 0x18
#define DW_SPI_RXFLTR 0x1c
#define DW_SPI_TXFLR 0x20
#define DW_SPI_RXFLR 0x24
#define DW_SPI_SR 0x28
#define DW_SPI_IMR 0x2c
#define DW_SPI_ISR 0x30
#define DW_SPI_RISR 0x34
#define DW_SPI_TXOICR 0x38
#define DW_SPI_RXOICR 0x3c
#define DW_SPI_RXUICR 0x40
#define DW_SPI_MSTICR 0x44
#define DW_SPI_ICR 0x48
#define DW_SPI_DMACR 0x4c
#define DW_SPI_DMATDLR 0x50
#define DW_SPI_DMARDLR 0x54
#define DW_SPI_IDR 0x58
#define DW_SPI_VERSION 0x5c
#define DW_SPI_DR 0x60
/* Bit fields in CTRLR0 */
#define SPI_DFS_OFFSET 0
#define SPI_FRF_OFFSET 4
#define SPI_FRF_SPI 0x0
#define SPI_FRF_SSP 0x1
#define SPI_FRF_MICROWIRE 0x2
#define SPI_FRF_RESV 0x3
#define SPI_MODE_OFFSET 6
#define SPI_SCPH_OFFSET 6
#define SPI_SCOL_OFFSET 7
#define SPI_TMOD_OFFSET 8
#define SPI_TMOD_MASK (0x3 << SPI_TMOD_OFFSET)
#define SPI_TMOD_TR 0x0 /* xmit & recv */
#define SPI_TMOD_TO 0x1 /* xmit only */
#define SPI_TMOD_RO 0x2 /* recv only */
#define SPI_TMOD_EPROMREAD 0x3 /* eeprom read mode */
#define SPI_SLVOE_OFFSET 10
#define SPI_SRL_OFFSET 11
#define SPI_CFS_OFFSET 12
/* Bit fields in SR, 7 bits */
#define SR_MASK 0x7f /* cover 7 bits */
#define SR_BUSY (1 << 0)
#define SR_TF_NOT_FULL (1 << 1)
#define SR_TF_EMPT (1 << 2)
#define SR_RF_NOT_EMPT (1 << 3)
#define SR_RF_FULL (1 << 4)
#define SR_TX_ERR (1 << 5)
#define SR_DCOL (1 << 6)
/* Bit fields in ISR, IMR, RISR, 7 bits */
#define SPI_INT_TXEI (1 << 0)
#define SPI_INT_TXOI (1 << 1)
#define SPI_INT_RXUI (1 << 2)
#define SPI_INT_RXOI (1 << 3)
#define SPI_INT_RXFI (1 << 4)
#define SPI_INT_MSTI (1 << 5)
/* Bit fields in DMACR */
#define SPI_DMA_RDMAE (1 << 0)
#define SPI_DMA_TDMAE (1 << 1)
/* TX RX interrupt level threshold, max can be 256 */
#define SPI_INT_THRESHOLD 32
enum dw_ssi_type {
SSI_MOTO_SPI = 0,
SSI_TI_SSP,
SSI_NS_MICROWIRE,
};
struct dw_spi;
struct dw_spi_dma_ops {
int (*dma_init)(struct dw_spi *dws);
void (*dma_exit)(struct dw_spi *dws);
int (*dma_setup)(struct dw_spi *dws, struct spi_transfer *xfer);
bool (*can_dma)(struct spi_master *master, struct spi_device *spi,
struct spi_transfer *xfer);
int (*dma_transfer)(struct dw_spi *dws, struct spi_transfer *xfer);
void (*dma_stop)(struct dw_spi *dws);
};
struct dw_spi {
struct spi_master *master;
enum dw_ssi_type type;
char name[16];
void __iomem *regs;
unsigned long paddr;
int irq;
u32 fifo_len; /* depth of the FIFO buffer */
u32 max_freq; /* max bus freq supported */
u32 reg_io_width; /* DR I/O width in bytes */
u16 bus_num;
u16 num_cs; /* supported slave numbers */
/* Current message transfer state info */
size_t len;
void *tx;
void *tx_end;
void *rx;
void *rx_end;
int dma_mapped;
u8 n_bytes; /* current is a 1/2 bytes op */
u32 dma_width;
irqreturn_t (*transfer_handler)(struct dw_spi *dws);
/* DMA info */
int dma_inited;
struct dma_chan *txchan;
struct dma_chan *rxchan;
unsigned long dma_chan_busy;
dma_addr_t dma_addr; /* phy address of the Data register */
struct dw_spi_dma_ops *dma_ops;
void *dma_tx;
void *dma_rx;
/* Bus interface info */
void *priv;
#ifdef CONFIG_DEBUG_FS
struct dentry *debugfs;
#endif
};
static inline u32 dw_readl(struct dw_spi *dws, u32 offset)
{
return __raw_readl(dws->regs + offset);
}
static inline u16 dw_readw(struct dw_spi *dws, u32 offset)
{
return __raw_readw(dws->regs + offset);
}
static inline void dw_writel(struct dw_spi *dws, u32 offset, u32 val)
{
__raw_writel(val, dws->regs + offset);
}
static inline void dw_writew(struct dw_spi *dws, u32 offset, u16 val)
{
__raw_writew(val, dws->regs + offset);
}
static inline u32 dw_read_io_reg(struct dw_spi *dws, u32 offset)
{
switch (dws->reg_io_width) {
case 2:
return dw_readw(dws, offset);
case 4:
default:
return dw_readl(dws, offset);
}
}
static inline void dw_write_io_reg(struct dw_spi *dws, u32 offset, u32 val)
{
switch (dws->reg_io_width) {
case 2:
dw_writew(dws, offset, val);
break;
case 4:
default:
dw_writel(dws, offset, val);
break;
}
}
static inline void spi_enable_chip(struct dw_spi *dws, int enable)
{
dw_writel(dws, DW_SPI_SSIENR, (enable ? 1 : 0));
}
static inline void spi_set_clk(struct dw_spi *dws, u16 div)
{
dw_writel(dws, DW_SPI_BAUDR, div);
}
/* Disable IRQ bits */
static inline void spi_mask_intr(struct dw_spi *dws, u32 mask)
{
u32 new_mask;
new_mask = dw_readl(dws, DW_SPI_IMR) & ~mask;
dw_writel(dws, DW_SPI_IMR, new_mask);
}
/* Enable IRQ bits */
static inline void spi_umask_intr(struct dw_spi *dws, u32 mask)
{
u32 new_mask;
new_mask = dw_readl(dws, DW_SPI_IMR) | mask;
dw_writel(dws, DW_SPI_IMR, new_mask);
}
/*
* This does disable the SPI controller, interrupts, and re-enable the
* controller back. Transmit and receive FIFO buffers are cleared when the
* device is disabled.
*/
static inline void spi_reset_chip(struct dw_spi *dws)
{
spi_enable_chip(dws, 0);
spi_mask_intr(dws, 0xff);
spi_enable_chip(dws, 1);
}
/*
* Each SPI slave device to work with dw_api controller should
* has such a structure claiming its working mode (poll or PIO/DMA),
* which can be save in the "controller_data" member of the
* struct spi_device.
*/
struct dw_spi_chip {
u8 poll_mode; /* 1 for controller polling mode */
u8 type; /* SPI/SSP/MicroWire */
void (*cs_control)(u32 command);
};
extern int dw_spi_add_host(struct device *dev, 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);
/* platform related setup */
extern int dw_spi_mid_init(struct dw_spi *dws); /* Intel MID platforms */
#endif /* DW_SPI_HEADER_H */