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incubator-nuttx/drivers/spi/spi_flash.c

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/************************************************************************************
* drivers/spi/spi_flash.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
************************************************************************************/
/************************************************************************************
* Included Files
************************************************************************************/
#include <nuttx/config.h>
#include <debug.h>
#include <string.h>
#include <nuttx/spi/spi_flash.h>
/************************************************************************************
* Pre-processor Definitions
************************************************************************************/
/* Configuration ********************************************************************/
/* Define the FLASH SIZE in bytes */
#ifdef CONFIG_SPI_FLASH_1M
# define CONFIG_SPI_FLASH_SIZE (128 * 1024)
# define CONFIG_SPI_FLASH_CAPACITY 0x11
#ifndef CONFIG_SPI_FLASH_SECTORSIZE
# define CONFIG_SPI_FLASH_SECTORSIZE 2048
#endif
#endif
#ifdef CONFIG_SPI_FLASH_8M
# define CONFIG_SPI_FLASH_SIZE (1024 * 1024)
# define CONFIG_SPI_FLASH_CAPACITY_SST26 0x3f
# define CONFIG_SPI_FLASH_CAPACITY 0x14
#endif
#ifdef CONFIG_SPI_FLASH_32M
# define CONFIG_SPI_FLASH_SIZE (4 * 1024 * 1024)
# define CONFIG_SPI_FLASH_CAPACITY_SST26 0x42
# define CONFIG_SPI_FLASH_CAPACITY 0x16
#endif
#ifdef CONFIG_SPI_FLASH_64M
# define CONFIG_SPI_FLASH_SIZE (8 * 1024 * 1024)
# define CONFIG_SPI_FLASH_CAPACITY_SST26 0x43
# define CONFIG_SPI_FLASH_CAPACITY 0x17
#endif
#ifdef CONFIG_SPI_FLASH_128M
# define CONFIG_SPI_FLASH_SIZE (16 * 1024 * 1024)
# define CONFIG_SPI_FLASH_CAPACITY_SST26 0x44
# define CONFIG_SPI_FLASH_CAPACITY 0x18
#endif
#ifndef CONFIG_SPI_FLASH_MANUFACTURER
# define CONFIG_SPI_FLASH_MANUFACTURER 0x20
#endif
#ifndef CONFIG_SPI_FLASH_MEMORY_TYPE
# define CONFIG_SPI_FLASH_MEMORY_TYPE 0x20
#endif
#ifndef CONFIG_SPI_FLASH_SECTORSIZE
# define CONFIG_SPI_FLASH_SECTORSIZE 65536
#endif
#ifndef CONFIG_SPI_FLASH_SUBSECTORSIZE
# define CONFIG_SPI_FLASH_SUBSECTORSIZE 4096
#endif
#ifndef CONFIG_SPI_FLASH_SECTORSIZE_MASK
# define CONFIG_SPI_FLASH_SECTORSIZE_MASK (~(CONFIG_SPI_FLASH_SECTORSIZE-1))
#endif
#ifndef CONFIG_SPI_FLASH_SUBSECTORSIZE_MASK
# define CONFIG_SPI_FLASH_SUBSECTORSIZE_MASK (~(CONFIG_SPI_FLASH_SUBSECTORSIZE-1))
#endif
#ifndef CONFIG_SPI_FLASH_PAGESIZE
# define CONFIG_SPI_FLASH_PAGESIZE 256
#endif
#ifndef CONFIG_SPI_FLASH_PAGESIZE_MASK
# define CONFIG_SPI_FLASH_PAGESIZE_MASK (CONFIG_SPI_FLASH_PAGESIZE-1)
#endif
/* Define FLASH States */
#define SPI_FLASH_STATE_IDLE 0
#define SPI_FLASH_STATE_RDID1 1
#define SPI_FLASH_STATE_RDID2 2
#define SPI_FLASH_STATE_RDID3 3
#define SPI_FLASH_STATE_WREN 4
#define SPI_FLASH_STATE_RDSR 5
#define SPI_FLASH_STATE_SE1 6
#define SPI_FLASH_STATE_SE2 7
#define SPI_FLASH_STATE_SE3 8
#define SPI_FLASH_STATE_PP1 9
#define SPI_FLASH_STATE_PP2 10
#define SPI_FLASH_STATE_PP3 11
#define SPI_FLASH_STATE_PP4 12
#define SPI_FLASH_STATE_READ1 13
#define SPI_FLASH_STATE_READ2 14
#define SPI_FLASH_STATE_READ3 15
#define SPI_FLASH_STATE_READ4 16
#define SPI_FLASH_STATE_FREAD_WAIT 17
/* Instructions */
/* Command Value N Description Addr Dummy Data */
#define SPI_FLASH_WREN 0x06 /* 1 Write Enable 0 0 0 */
#define SPI_FLASH_WRDI 0x04 /* 1 Write Disable 0 0 0 */
#define SPI_FLASH_RDID 0x9f /* 1 Read Identification 0 0 1-3 */
#define SPI_FLASH_RDSR 0x05 /* 1 Read Status Register 0 0 >=1 */
#define SPI_FLASH_WRSR 0x01 /* 1 Write Status Register 0 0 1 */
#define SPI_FLASH_READ 0x03 /* 1 Read Data Bytes 3 0 >=1 */
#define SPI_FLASH_FAST_READ 0x0b /* 1 Higher speed read 3 1 >=1 */
#define SPI_FLASH_PP 0x02 /* 1 Page Program 3 0 1-256 */
#define SPI_FLASH_SE 0xd8 /* 1 Sector Erase 3 0 0 */
#define SPI_FLASH_BE 0xc7 /* 1 Bulk Erase 0 0 0 */
#define SPI_FLASH_DP 0xb9 /* 2 Deep power down 0 0 0 */
#define SPI_FLASH_RES 0xab /* 2 Read Electronic Signature 0 3 >=1 */
#define SPI_FLASH_SSE 0x20 /* 3 Sub-Sector Erase 0 0 0 */
#define SPI_FLASH_DUMMY 0xa5
/************************************************************************************
* Private Types
************************************************************************************/
struct spi_flash_dev_s
{
struct spi_dev_s spidev; /* Externally visible part of the SPI interface */
FAR const char * name; /* Name of the flash type (m25p, w25, etc.) */
uint8_t manuf;
uint8_t type;
uint8_t capacity;
uint8_t last_cmd;
uint32_t selected; /* SPIn base address */
uint32_t read_data;
int wren;
int state;
unsigned long address;
unsigned char data[CONFIG_SPI_FLASH_SIZE];
};
/************************************************************************************
* Private Function Prototypes
************************************************************************************/
/* SPI methods */
static int spi_flash_lock(FAR struct spi_dev_s *dev, bool lock);
static uint32_t spi_flash_setfrequency(FAR struct spi_dev_s *dev,
uint32_t frequency);
static void spi_flash_setmode(FAR struct spi_dev_s *dev,
enum spi_mode_e mode);
static void spi_flash_setbits(FAR struct spi_dev_s *dev, int nbits);
static uint32_t spi_flash_send(FAR struct spi_dev_s *dev, uint32_t wd);
static void spi_flash_exchange(FAR struct spi_dev_s *dev,
FAR const void *txbuffer, FAR void *rxbuffer,
size_t nwords);
static void spi_flash_select(FAR struct spi_dev_s *dev, uint32_t devid,
bool selected);
static uint8_t spi_flash_status(FAR struct spi_dev_s *dev, uint32_t devid);
#ifdef CONFIG_SPI_CMDDATA
static int spi_flash_cmddata(FAR struct spi_dev_s *dev, uint32_t devid,
bool cmd);
#endif
#ifndef CONFIG_SPI_EXCHANGE
static void spi_flash_sndblock(FAR struct spi_dev_s *dev,
FAR const void *txbuffer, size_t nwords);
static void spi_flash_recvblock(FAR struct spi_dev_s *dev, FAR void *rxbuffer,
size_t nwords);
#endif
static void spi_flash_writeword(FAR struct spi_flash_dev_s *priv, uint16_t data);
static uint32_t spi_flash_readword(FAR struct spi_flash_dev_s *priv);
/************************************************************************************
* Private Data
************************************************************************************/
static const struct spi_ops_s g_spiops =
{
spi_flash_lock, /* lock */
spi_flash_select, /* select */
spi_flash_setfrequency, /* setfrequency */
#ifdef CONFIG_SPI_DELAY_CONTROL
NULL, /* setdelay */
#endif
spi_flash_setmode, /* setmode */
spi_flash_setbits, /* setbits */
#ifdef CONFIG_SPI_HWFEATURES
NULL, /* hwfeatures */
#endif
spi_flash_status, /* status */
#ifdef CONFIG_SPI_CMDDATA
spi_flash_cmddata, /* cmddata */
#endif
spi_flash_send, /* send */
#ifdef CONFIG_SPI_EXCHANGE
spi_flash_exchange, /* exchange */
#else
spi_flash_sndblock, /* sndblock */
spi_flash_recvblock, /* recvblock */
#endif
#ifdef CONFIG_SPI_TRIGGER
NULL, /* trigger */
#endif
NULL /* registercallback */
};
#ifdef CONFIG_SPI_FLASH_M25P
struct spi_flash_dev_s g_spidev_m25p =
{
{
&g_spiops /* spidev */
},
"m25p", /* name */
0x20, /* manuf */
0x20, /* type */
CONFIG_SPI_FLASH_CAPACITY /* capacity */
};
#endif
#ifdef CONFIG_SPI_FLASH_SST26
struct spi_flash_dev_s g_spidev_sst26 =
{
{
&g_spiops /* spidev */
},
"sst26", /* name */
0xbf, /* manuf */
#ifdef CONFIG_SST26_MEMORY_TYPE
CONFIG_SST26_MEMORY_TYPE, /* type */
#else
0x25, /* type */
#endif
CONFIG_SPI_FLASH_CAPACITY_SST26 /* capacity */
};
#endif
#ifdef CONFIG_SPI_FLASH_W25
struct spi_flash_dev_s g_spidev_w25 =
{
{
&g_spiops /* spidev */
},
"w25", /* name */
0xef, /* manuf */
0x30, /* type */
CONFIG_SPI_FLASH_CAPACITY /* capacity */
};
#endif
#ifdef CONFIG_SPI_FLASH_CUSTOM
struct spi_flash_dev_s g_spidev_custom =
{
{
&g_spiops /* spidev */
},
"custom", /* name */
CONFIG_SPI_FLASH_MANUFACTURER, /* manuf */
CONFIG_SPI_FLASH_MEMORY_TYPE, /* type */
CONFIG_SPI_FLASH_CAPACITY /* capacity */
};
#endif
struct spi_flash_dev_s *gp_spidev[] =
{
#ifdef CONFIG_SPI_FLASH_M25P
&g_spidev_m25p,
#endif
#ifdef CONFIG_SPI_FLASH_SST26
&g_spidev_sst26,
#endif
#ifdef CONFIG_SPI_FLASH_W25
&g_spidev_w25,
#endif
#ifdef CONFIG_SPI_FLASH_CUSTOM
&g_spidev_custom,
#endif
/* Null termination pointer at end of list */
NULL
};
/************************************************************************************
* Private Functions
************************************************************************************/
/************************************************************************************
* Name: spi_flash_lock
*
* Description:
* On SPI buses where there are multiple devices, it will be necessary to
* lock SPI to have exclusive access to the buses for a sequence of
* transfers. The bus should be locked before the chip is selected. After
* locking the SPI bus, the caller should then also call the setfrequency,
* setbits, and setmode methods to make sure that the SPI is properly
* configured for the device. If the SPI bus is being shared, then it
* may have been left in an incompatible state.
*
* Input Parameters:
* dev - Device-specific state data
* lock - true: Lock spi bus, false: unlock SPI bus
*
* Returned Value:
* None
*
************************************************************************************/
static int spi_flash_lock(FAR struct spi_dev_s *dev, bool lock)
{
return OK;
}
/************************************************************************************
* Name: spi_flash_select
*
* Description:
* Process select logic for the FLASH.
*
* Returned Value:
* None
*
************************************************************************************/
static void spi_flash_select(FAR struct spi_dev_s *dev, uint32_t devid,
bool selected)
{
FAR struct spi_flash_dev_s *priv = (FAR struct spi_flash_dev_s *)dev;
if (devid == SPIDEV_FLASH(0))
{
priv->selected = selected;
/* As part of an de-select, ensure the WREN bit is cleared */
if (!selected)
{
if (priv->last_cmd != SPI_FLASH_WREN)
{
priv->wren = 0;
}
priv->state = SPI_FLASH_STATE_IDLE;
}
}
}
/************************************************************************************
* Name: spi_flash_cmddata
*
* Description:
* Perform SPI Command operations
*
* Returned Value:
* Always returns zero
*
************************************************************************************/
#ifdef CONFIG_SPI_CMDDATA
static int spi_flash_cmddata(FAR struct spi_dev_s *dev, uint32_t devid, bool cmd)
{
return 0;
}
#endif
/************************************************************************************
* Name: spi_flash_setfrequency
*
* Description:
* Set the SPI frequency.
*
* Input Parameters:
* dev - Device-specific state data
* frequency - The SPI frequency requested
*
* Returned Value:
* Returns the actual frequency selected
*
************************************************************************************/
static uint32_t spi_flash_setfrequency(FAR struct spi_dev_s *dev, uint32_t frequency)
{
return frequency;
}
/************************************************************************************
* Name: spi_flash_setmode
*
* Description:
* Set the SPI mode. see enum spi_mode_e for mode definitions
*
* Input Parameters:
* dev - Device-specific state data
* mode - The SPI mode requested
*
* Returned Value:
* Returns the actual frequency selected
*
************************************************************************************/
static void spi_flash_setmode(FAR struct spi_dev_s *dev, enum spi_mode_e mode)
{
}
/************************************************************************************
* Name: spi_flash_setbits
*
* Description:
* Set the number of bits per word.
*
* Input Parameters:
* dev - Device-specific state data
* nbits - The number of bits requested
*
* Returned Value:
* None
*
************************************************************************************/
static void spi_flash_setbits(FAR struct spi_dev_s *dev, int nbits)
{
}
/************************************************************************************
* Name: spi_flash_status
*
* Description:
* Set the SPI bus status
*
* Returned Value:
* Always returns zero
*
************************************************************************************/
static uint8_t spi_flash_status(FAR struct spi_dev_s *dev, uint32_t devid)
{
return 0;
}
/************************************************************************************
* Name: spi_flash_send
*
* Description:
* Exchange one word on SPI
*
* Input Parameters:
* dev - Device-specific state data
* wd - The word to send. the size of the data is determined by the
* number of bits selected for the SPI interface.
*
* Returned Value:
* response
*
************************************************************************************/
static uint32_t spi_flash_send(FAR struct spi_dev_s *dev, uint32_t wd)
{
FAR struct spi_flash_dev_s *priv = (FAR struct spi_flash_dev_s *)dev;
uint32_t ret;
if (priv->selected)
{
spi_flash_writeword(priv, wd);
ret = spi_flash_readword(priv);
}
else
{
ret = 0xff;
}
return ret;
}
/************************************************************************************
* Name: spi_flash_exchange (no DMA). aka spi_exchange_nodma
*
* Description:
* Exchange a block of data on SPI without using DMA
*
* Input Parameters:
* dev - Device-specific state data
* txbuffer - A pointer to the buffer of data to be sent
* rxbuffer - A pointer to a buffer in which to receive data
* nwords - the length of data to be exchanged in units of words.
* The wordsize is determined by the number of bits-per-word
* selected for the SPI interface. If nbits <= 8, the data is
* packed into uint8_t's; if nbits >8, the data is packed into
* uint16_t's
*
* Returned Value:
* None
*
************************************************************************************/
static void spi_flash_exchange(FAR struct spi_dev_s *dev, FAR const void *txbuffer,
FAR void *rxbuffer, size_t nwords)
{
spiinfo("txbuffer=%p rxbuffer=%p nwords=%zu\n", txbuffer, rxbuffer, nwords);
/* 8-bit mode */
FAR const uint8_t *src = (FAR const uint8_t *)txbuffer;
FAR uint8_t *dest = (FAR uint8_t *)rxbuffer;
uint8_t word;
while (nwords-- > 0)
{
/* Get the next word to write. Is there a source buffer? */
if (src)
{
word = *src++;
}
else
{
word = 0xff;
}
/* Exchange one word */
word = (uint8_t)spi_flash_send(dev, (uint16_t)word);
/* Is there a buffer to receive the return value? */
if (dest)
{
*dest++ = word;
}
}
}
/************************************************************************************
* Name: spi_sndblock
*
* Description:
* Send a block of data on SPI
*
* Input Parameters:
* dev - Device-specific state data
* txbuffer - A pointer to the buffer of data to be sent
* nwords - the length of data to send from the buffer in number of words.
* The wordsize is determined by the number of bits-per-word
* selected for the SPI interface. If nbits <= 8, the data is
* packed into uint8_t's; if nbits >8, the data is packed into
* uint16_t's
*
* Returned Value:
* None
*
************************************************************************************/
#ifndef CONFIG_SPI_EXCHANGE
static void spi_flash_sndblock(FAR struct spi_dev_s *dev, FAR const void *txbuffer,
size_t nwords)
{
spiinfo("txbuffer=%p nwords=%d\n", txbuffer, nwords);
return spi_flash_exchange(dev, txbuffer, NULL, nwords);
}
#endif
/************************************************************************************
* Name: spi_recvblock
*
* Description:
* Receive a block of data from SPI
*
* Input Parameters:
* dev - Device-specific state data
* rxbuffer - A pointer to the buffer in which to receive data
* nwords - the length of data that can be received in the buffer in number
* of words. The wordsize is determined by the number of bits-per-word
* selected for the SPI interface. If nbits <= 8, the data is
* packed into uint8_t's; if nbits >8, the data is packed into
* uint16_t's
*
* Returned Value:
* None
*
************************************************************************************/
#ifndef CONFIG_SPI_EXCHANGE
static void spi_flash_recvblock(FAR struct spi_dev_s *dev, FAR void *rxbuffer,
size_t nwords)
{
spiinfo("rxbuffer=%p nwords=%d\n", rxbuffer, nwords);
return spi_flash_exchange(dev, NULL, rxbuffer, nwords);
}
#endif
/************************************************************************************
* Name: spi_flash_sectorerase
*
* Description:
* Erase one sector
*
* Input Parameters:
* priv - Device-specific state data
*
* Returned Value:
* None
*
************************************************************************************/
static void spi_flash_sectorerase(FAR struct spi_flash_dev_s *priv)
{
uint32_t address;
uint32_t len = 0;
/* Ensure the WREN bit is set before any erase operation */
if (priv->wren)
{
address = priv->address;
if (priv->last_cmd == SPI_FLASH_SE)
{
address &= CONFIG_SPI_FLASH_SECTORSIZE_MASK;
len = CONFIG_SPI_FLASH_SECTORSIZE;
}
else if (priv->last_cmd == SPI_FLASH_SSE)
{
address &= CONFIG_SPI_FLASH_SUBSECTORSIZE_MASK;
len = CONFIG_SPI_FLASH_SUBSECTORSIZE;
}
/* Now perform the erase */
memset(&priv->data[address], 0xff, len);
}
}
/************************************************************************************
* Name: spi_flash_writeword
*
* Description:
* Write a word (byte in our case) to the FLASH state machine.
*
* Input Parameters:
* dev - Device-specific state data
* data - the data to send to the simulated FLASH
*
* Returned Value:
* None
*
************************************************************************************/
static void spi_flash_writeword(FAR struct spi_flash_dev_s *priv, uint16_t data)
{
switch (priv->state)
{
case SPI_FLASH_STATE_IDLE:
priv->last_cmd = data;
priv->read_data = 0xff;
switch (data)
{
case SPI_FLASH_RDID:
priv->state = SPI_FLASH_STATE_RDID1;
break;
case SPI_FLASH_WREN:
priv->wren = 1;
priv->state = SPI_FLASH_STATE_WREN;
break;
case SPI_FLASH_RDSR:
priv->state = SPI_FLASH_STATE_RDSR;
break;
/* Sector / Subsector erase */
case SPI_FLASH_SE:
case SPI_FLASH_SSE:
priv->state = SPI_FLASH_STATE_SE1;
break;
/* Bulk Erase */
case SPI_FLASH_BE:
priv->state = SPI_FLASH_STATE_IDLE;
if (priv->wren)
{
memset(priv->data, 0xff, CONFIG_SPI_FLASH_SIZE);
}
break;
case SPI_FLASH_PP:
priv->state = SPI_FLASH_STATE_PP1;
break;
case SPI_FLASH_READ:
case SPI_FLASH_FAST_READ:
priv->state = SPI_FLASH_STATE_READ1;
break;
default:
break;
}
break;
/* Read ID States */
case SPI_FLASH_STATE_RDID1:
priv->read_data = priv->manuf; /* CONFIG_SPI_FLASH_MANUFACTURER; */
priv->state = SPI_FLASH_STATE_RDID2;
break;
case SPI_FLASH_STATE_RDID2:
priv->read_data = priv->type; /* CONFIG_SPI_FLASH_MEMORY_TYPE; */
priv->state = SPI_FLASH_STATE_RDID3;
break;
case SPI_FLASH_STATE_RDID3:
priv->read_data = priv->capacity; /* CONFIG_SPI_FLASH_CAPACITY; */
priv->state = SPI_FLASH_STATE_IDLE;
break;
/* WREN state - if we receive any bytes here, then we abort the WREN */
case SPI_FLASH_STATE_WREN:
priv->wren = 0;
break;
/* Read Status Register state */
case SPI_FLASH_STATE_RDSR:
priv->read_data = 0;
priv->state = SPI_FLASH_STATE_IDLE;
break;
/* Sector and Sub-Sector erase states - Read the address */
case SPI_FLASH_STATE_SE1:
priv->address = data << 16;
priv->state = SPI_FLASH_STATE_SE2;
break;
case SPI_FLASH_STATE_SE2:
priv->address |= data << 8;
priv->state = SPI_FLASH_STATE_SE3;
break;
case SPI_FLASH_STATE_SE3:
priv->address |= data;
/* Now perform the sector or sub-sector erase. Really this should
* be done during the deselect, but this is just a simulation .
*/
spi_flash_sectorerase(priv);
break;
/* Page Program. We could reuse the SE states, but let's keep it clean. */
case SPI_FLASH_STATE_PP1:
priv->address = data << 16;
priv->state = SPI_FLASH_STATE_PP2;
break;
case SPI_FLASH_STATE_PP2:
priv->address |= data << 8;
priv->state = SPI_FLASH_STATE_PP3;
break;
case SPI_FLASH_STATE_PP3:
priv->address |= data;
priv->state = SPI_FLASH_STATE_PP4;
break;
case SPI_FLASH_STATE_PP4:
/* In this state we actually write data (if WREN enabled) */
if (priv->wren)
{
priv->data[priv->address] = data;
}
/* Now increment the address. We do a page wrap here to simulate
* the actual FLASH.
*/
if ((priv->address & CONFIG_SPI_FLASH_PAGESIZE_MASK) ==
CONFIG_SPI_FLASH_PAGESIZE_MASK)
{
priv->address &= !CONFIG_SPI_FLASH_PAGESIZE_MASK;
}
else
{
priv->address++;
}
break;
/* Read data */
case SPI_FLASH_STATE_READ1:
priv->address = data << 16;
priv->state = SPI_FLASH_STATE_READ2;
break;
case SPI_FLASH_STATE_READ2:
priv->address |= data << 8;
priv->state = SPI_FLASH_STATE_READ3;
break;
case SPI_FLASH_STATE_READ3:
priv->address |= data;
if (priv->last_cmd == SPI_FLASH_FAST_READ)
{
priv->state = SPI_FLASH_STATE_FREAD_WAIT;
}
else
{
priv->state = SPI_FLASH_STATE_READ4;
}
break;
case SPI_FLASH_STATE_FREAD_WAIT:
priv->read_data = 0xff;
priv->state = SPI_FLASH_STATE_READ4;
break;
case SPI_FLASH_STATE_READ4:
/* In this state perform data reads until de-selected. */
priv->read_data = priv->data[priv->address++];
if (priv->address == CONFIG_SPI_FLASH_SIZE)
{
priv->address = 0;
}
break;
default:
priv->state = SPI_FLASH_STATE_IDLE;
priv->read_data = 0xff;
break;
}
}
/************************************************************************************
* Name: spi_flash_readword
*
* Description:
* Read a word (byte in our case) from the simulated FLASH.
*
* Input Parameters:
* priv - Device-specific state data
*
* Returned Value:
* Byte read from the simulated FLASH device
*
************************************************************************************/
static uint32_t spi_flash_readword(FAR struct spi_flash_dev_s *priv)
{
return priv->read_data;
}
/************************************************************************************
* Public Functions
************************************************************************************/
/************************************************************************************
* Name: up_spi_flashinitialize
*
* Description:
* Initialize the selected SPI port
*
* Input Parameters:
* Port number (for hardware that has multiple SPI interfaces)
*
* Returned Value:
* Valid SPI device structure reference on success; a NULL on failure
*
************************************************************************************/
FAR struct spi_dev_s *spi_flash_initialize(FAR const char *name)
{
FAR struct spi_flash_dev_s *priv = NULL;
int x;
/* Default to custom FLASH if not specified */
if (name == NULL)
{
name = "custom";
}
/* Loop through all supported flash devices */
for (x = 0; gp_spidev[x] != NULL; x++)
{
/* Search for the specified flash by name */
if (strcmp(name, gp_spidev[x]->name) == 0)
{
break;
}
}
/* Test if flash device found */
if (gp_spidev[x] == NULL)
{
/* Specified device not supported */
return NULL;
}
/* Configure the selected flash device */
priv = gp_spidev[x];
priv->selected = 0;
priv->wren = 0;
priv->address = 0;
priv->state = SPI_FLASH_STATE_IDLE;
priv->read_data = 0xff;
priv->last_cmd = 0xff;
memset(&priv->data[0], 0xff, sizeof(priv->data));
return (FAR struct spi_dev_s *)priv;
}
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