diff options
Diffstat (limited to 'drivers/staging/sm750fb/ddk750_swi2c.c')
| -rw-r--r-- | drivers/staging/sm750fb/ddk750_swi2c.c | 296 |
1 files changed, 151 insertions, 145 deletions
diff --git a/drivers/staging/sm750fb/ddk750_swi2c.c b/drivers/staging/sm750fb/ddk750_swi2c.c index 5133bccf17bd..8d644a7cba52 100644 --- a/drivers/staging/sm750fb/ddk750_swi2c.c +++ b/drivers/staging/sm750fb/ddk750_swi2c.c @@ -15,7 +15,6 @@ #include "ddk750_swi2c.h" #include "ddk750_power.h" - /******************************************************************* * I2C Software Master Driver: * =========================== @@ -55,8 +54,8 @@ ******************************************************************/ /* GPIO pins used for this I2C. It ranges from 0 to 63. */ -static unsigned char g_i2cClockGPIO = DEFAULT_I2C_SCL; -static unsigned char g_i2cDataGPIO = DEFAULT_I2C_SDA; +static unsigned char sw_i2c_clk_gpio = DEFAULT_I2C_SCL; +static unsigned char sw_i2c_data_gpio = DEFAULT_I2C_SDA; /* * Below is the variable declaration for the GPIO pin register usage @@ -70,19 +69,19 @@ static unsigned char g_i2cDataGPIO = DEFAULT_I2C_SDA; */ /* i2c Clock GPIO Register usage */ -static unsigned long g_i2cClkGPIOMuxReg = GPIO_MUX; -static unsigned long g_i2cClkGPIODataReg = GPIO_DATA; -static unsigned long g_i2cClkGPIODataDirReg = GPIO_DATA_DIRECTION; +static unsigned long sw_i2c_clk_gpio_mux_reg = GPIO_MUX; +static unsigned long sw_i2c_clk_gpio_data_reg = GPIO_DATA; +static unsigned long sw_i2c_clk_gpio_data_dir_reg = GPIO_DATA_DIRECTION; /* i2c Data GPIO Register usage */ -static unsigned long g_i2cDataGPIOMuxReg = GPIO_MUX; -static unsigned long g_i2cDataGPIODataReg = GPIO_DATA; -static unsigned long g_i2cDataGPIODataDirReg = GPIO_DATA_DIRECTION; +static unsigned long sw_i2c_data_gpio_mux_reg = GPIO_MUX; +static unsigned long sw_i2c_data_gpio_data_reg = GPIO_DATA; +static unsigned long sw_i2c_data_gpio_data_dir_reg = GPIO_DATA_DIRECTION; /* * This function puts a delay between command */ -static void swI2CWait(void) +static void sw_i2c_wait(void) { /* find a bug: * peekIO method works well before suspend/resume @@ -91,20 +90,17 @@ static void swI2CWait(void) * never finish. * use non-ultimate for loop below is safe * */ -#if 0 + /* Change wait algorithm to use PCI bus clock, it's more reliable than counter loop .. write 0x61 to 0x3ce and read from 0x3cf */ - while (peekIO(0x3ce, 0x61) & 0x10); -#else - int i, Temp; + int i, tmp; for (i = 0; i < 600; i++) { - Temp = i; - Temp += i; + tmp = i; + tmp += i; } -#endif } /* @@ -119,25 +115,28 @@ static void swI2CWait(void) * signal because the i2c will fail when other device try to drive the * signal due to SM50x will drive the signal to always high. */ -void swI2CSCL(unsigned char value) +static void sw_i2c_scl(unsigned char value) { - unsigned long ulGPIOData; - unsigned long ulGPIODirection; + unsigned long gpio_data; + unsigned long gpio_dir; - ulGPIODirection = PEEK32(g_i2cClkGPIODataDirReg); + gpio_dir = PEEK32(sw_i2c_clk_gpio_data_dir_reg); if (value) { /* High */ - /* Set direction as input. This will automatically pull the signal up. */ - ulGPIODirection &= ~(1 << g_i2cClockGPIO); - POKE32(g_i2cClkGPIODataDirReg, ulGPIODirection); + /* + * Set direction as input. This will automatically + * pull the signal up. + */ + gpio_dir &= ~(1 << sw_i2c_clk_gpio); + POKE32(sw_i2c_clk_gpio_data_dir_reg, gpio_dir); } else { /* Low */ /* Set the signal down */ - ulGPIOData = PEEK32(g_i2cClkGPIODataReg); - ulGPIOData &= ~(1 << g_i2cClockGPIO); - POKE32(g_i2cClkGPIODataReg, ulGPIOData); + gpio_data = PEEK32(sw_i2c_clk_gpio_data_reg); + gpio_data &= ~(1 << sw_i2c_clk_gpio); + POKE32(sw_i2c_clk_gpio_data_reg, gpio_data); /* Set direction as output */ - ulGPIODirection |= (1 << g_i2cClockGPIO); - POKE32(g_i2cClkGPIODataDirReg, ulGPIODirection); + gpio_dir |= (1 << sw_i2c_clk_gpio); + POKE32(sw_i2c_clk_gpio_data_dir_reg, gpio_dir); } } @@ -153,25 +152,28 @@ void swI2CSCL(unsigned char value) * signal because the i2c will fail when other device try to drive the * signal due to SM50x will drive the signal to always high. */ -void swI2CSDA(unsigned char value) +static void sw_i2c_sda(unsigned char value) { - unsigned long ulGPIOData; - unsigned long ulGPIODirection; + unsigned long gpio_data; + unsigned long gpio_dir; - ulGPIODirection = PEEK32(g_i2cDataGPIODataDirReg); + gpio_dir = PEEK32(sw_i2c_data_gpio_data_dir_reg); if (value) { /* High */ - /* Set direction as input. This will automatically pull the signal up. */ - ulGPIODirection &= ~(1 << g_i2cDataGPIO); - POKE32(g_i2cDataGPIODataDirReg, ulGPIODirection); + /* + * Set direction as input. This will automatically + * pull the signal up. + */ + gpio_dir &= ~(1 << sw_i2c_data_gpio); + POKE32(sw_i2c_data_gpio_data_dir_reg, gpio_dir); } else { /* Low */ /* Set the signal down */ - ulGPIOData = PEEK32(g_i2cDataGPIODataReg); - ulGPIOData &= ~(1 << g_i2cDataGPIO); - POKE32(g_i2cDataGPIODataReg, ulGPIOData); + gpio_data = PEEK32(sw_i2c_data_gpio_data_reg); + gpio_data &= ~(1 << sw_i2c_data_gpio); + POKE32(sw_i2c_data_gpio_data_reg, gpio_data); /* Set direction as output */ - ulGPIODirection |= (1 << g_i2cDataGPIO); - POKE32(g_i2cDataGPIODataDirReg, ulGPIODirection); + gpio_dir |= (1 << sw_i2c_data_gpio); + POKE32(sw_i2c_data_gpio_data_dir_reg, gpio_dir); } } @@ -181,21 +183,22 @@ void swI2CSDA(unsigned char value) * Return Value: * The SDA data bit sent by the Slave */ -static unsigned char swI2CReadSDA(void) +static unsigned char sw_i2c_read_sda(void) { - unsigned long ulGPIODirection; - unsigned long ulGPIOData; + unsigned long gpio_dir; + unsigned long gpio_data; + unsigned long dir_mask = 1 << sw_i2c_data_gpio; /* Make sure that the direction is input (High) */ - ulGPIODirection = PEEK32(g_i2cDataGPIODataDirReg); - if ((ulGPIODirection & (1 << g_i2cDataGPIO)) != (~(1 << g_i2cDataGPIO))) { - ulGPIODirection &= ~(1 << g_i2cDataGPIO); - POKE32(g_i2cDataGPIODataDirReg, ulGPIODirection); + gpio_dir = PEEK32(sw_i2c_data_gpio_data_dir_reg); + if ((gpio_dir & dir_mask) != ~dir_mask) { + gpio_dir &= ~(1 << sw_i2c_data_gpio); + POKE32(sw_i2c_data_gpio_data_dir_reg, gpio_dir); } /* Now read the SDA line */ - ulGPIOData = PEEK32(g_i2cDataGPIODataReg); - if (ulGPIOData & (1 << g_i2cDataGPIO)) + gpio_data = PEEK32(sw_i2c_data_gpio_data_reg); + if (gpio_data & (1 << sw_i2c_data_gpio)) return 1; else return 0; @@ -204,7 +207,7 @@ static unsigned char swI2CReadSDA(void) /* * This function sends ACK signal */ -static void swI2CAck(void) +static void sw_i2c_ack(void) { return; /* Single byte read is ok without it. */ } @@ -212,23 +215,23 @@ static void swI2CAck(void) /* * This function sends the start command to the slave device */ -static void swI2CStart(void) +static void sw_i2c_start(void) { /* Start I2C */ - swI2CSDA(1); - swI2CSCL(1); - swI2CSDA(0); + sw_i2c_sda(1); + sw_i2c_scl(1); + sw_i2c_sda(0); } /* * This function sends the stop command to the slave device */ -static void swI2CStop(void) +static void sw_i2c_stop(void) { /* Stop the I2C */ - swI2CSCL(1); - swI2CSDA(0); - swI2CSDA(1); + sw_i2c_scl(1); + sw_i2c_sda(0); + sw_i2c_sda(1); } /* @@ -241,7 +244,7 @@ static void swI2CStop(void) * 0 - Success * -1 - Fail to write byte */ -static long swI2CWriteByte(unsigned char data) +static long sw_i2c_write_byte(unsigned char data) { unsigned char value = data; int i; @@ -249,47 +252,47 @@ static long swI2CWriteByte(unsigned char data) /* Sending the data bit by bit */ for (i = 0; i < 8; i++) { /* Set SCL to low */ - swI2CSCL(0); + sw_i2c_scl(0); /* Send data bit */ if ((value & 0x80) != 0) - swI2CSDA(1); + sw_i2c_sda(1); else - swI2CSDA(0); + sw_i2c_sda(0); - swI2CWait(); + sw_i2c_wait(); /* Toggle clk line to one */ - swI2CSCL(1); - swI2CWait(); + sw_i2c_scl(1); + sw_i2c_wait(); /* Shift byte to be sent */ value = value << 1; } /* Set the SCL Low and SDA High (prepare to get input) */ - swI2CSCL(0); - swI2CSDA(1); + sw_i2c_scl(0); + sw_i2c_sda(1); /* Set the SCL High for ack */ - swI2CWait(); - swI2CSCL(1); - swI2CWait(); + sw_i2c_wait(); + sw_i2c_scl(1); + sw_i2c_wait(); /* Read SDA, until SDA==0 */ for (i = 0; i < 0xff; i++) { - if (!swI2CReadSDA()) + if (!sw_i2c_read_sda()) break; - swI2CSCL(0); - swI2CWait(); - swI2CSCL(1); - swI2CWait(); + sw_i2c_scl(0); + sw_i2c_wait(); + sw_i2c_scl(1); + sw_i2c_wait(); } /* Set the SCL Low and SDA High */ - swI2CSCL(0); - swI2CSDA(1); + sw_i2c_scl(0); + sw_i2c_sda(1); if (i < 0xff) return 0; @@ -307,31 +310,31 @@ static long swI2CWriteByte(unsigned char data) * Return Value: * One byte data read from the Slave device */ -static unsigned char swI2CReadByte(unsigned char ack) +static unsigned char sw_i2c_read_byte(unsigned char ack) { int i; unsigned char data = 0; for (i = 7; i >= 0; i--) { /* Set the SCL to Low and SDA to High (Input) */ - swI2CSCL(0); - swI2CSDA(1); - swI2CWait(); + sw_i2c_scl(0); + sw_i2c_sda(1); + sw_i2c_wait(); /* Set the SCL High */ - swI2CSCL(1); - swI2CWait(); + sw_i2c_scl(1); + sw_i2c_wait(); /* Read data bits from SDA */ - data |= (swI2CReadSDA() << i); + data |= (sw_i2c_read_sda() << i); } if (ack) - swI2CAck(); + sw_i2c_ack(); /* Set the SCL Low and SDA High */ - swI2CSCL(0); - swI2CSDA(1); + sw_i2c_scl(0); + sw_i2c_sda(1); return data; } @@ -340,37 +343,37 @@ static unsigned char swI2CReadByte(unsigned char ack) * This function initializes GPIO port for SW I2C communication. * * Parameters: - * i2cClkGPIO - The GPIO pin to be used as i2c SCL - * i2cDataGPIO - The GPIO pin to be used as i2c SDA + * clk_gpio - The GPIO pin to be used as i2c SCL + * data_gpio - The GPIO pin to be used as i2c SDA * * Return Value: * -1 - Fail to initialize the i2c * 0 - Success */ -static long swI2CInit_SM750LE(unsigned char i2cClkGPIO, - unsigned char i2cDataGPIO) +static long sm750le_i2c_init(unsigned char clk_gpio, + unsigned char data_gpio) { int i; /* Initialize the GPIO pin for the i2c Clock Register */ - g_i2cClkGPIODataReg = GPIO_DATA_SM750LE; - g_i2cClkGPIODataDirReg = GPIO_DATA_DIRECTION_SM750LE; + sw_i2c_clk_gpio_data_reg = GPIO_DATA_SM750LE; + sw_i2c_clk_gpio_data_dir_reg = GPIO_DATA_DIRECTION_SM750LE; /* Initialize the Clock GPIO Offset */ - g_i2cClockGPIO = i2cClkGPIO; + sw_i2c_clk_gpio = clk_gpio; /* Initialize the GPIO pin for the i2c Data Register */ - g_i2cDataGPIODataReg = GPIO_DATA_SM750LE; - g_i2cDataGPIODataDirReg = GPIO_DATA_DIRECTION_SM750LE; + sw_i2c_data_gpio_data_reg = GPIO_DATA_SM750LE; + sw_i2c_data_gpio_data_dir_reg = GPIO_DATA_DIRECTION_SM750LE; /* Initialize the Data GPIO Offset */ - g_i2cDataGPIO = i2cDataGPIO; + sw_i2c_data_gpio = data_gpio; /* Note that SM750LE don't have GPIO MUX and power is always on */ /* Clear the i2c lines. */ for (i = 0; i < 9; i++) - swI2CStop(); + sw_i2c_stop(); return 0; } @@ -379,55 +382,58 @@ static long swI2CInit_SM750LE(unsigned char i2cClkGPIO, * This function initializes the i2c attributes and bus * * Parameters: - * i2cClkGPIO - The GPIO pin to be used as i2c SCL - * i2cDataGPIO - The GPIO pin to be used as i2c SDA + * clk_gpio - The GPIO pin to be used as i2c SCL + * data_gpio - The GPIO pin to be used as i2c SDA * * Return Value: * -1 - Fail to initialize the i2c * 0 - Success */ -long swI2CInit( - unsigned char i2cClkGPIO, - unsigned char i2cDataGPIO +long sm750_sw_i2c_init( + unsigned char clk_gpio, + unsigned char data_gpio ) { int i; - /* Return 0 if the GPIO pins to be used is out of range. The range is only from [0..63] */ - if ((i2cClkGPIO > 31) || (i2cDataGPIO > 31)) + /* + * Return 0 if the GPIO pins to be used is out of range. The + * range is only from [0..63] + */ + if ((clk_gpio > 31) || (data_gpio > 31)) return -1; if (getChipType() == SM750LE) - return swI2CInit_SM750LE(i2cClkGPIO, i2cDataGPIO); + return sm750le_i2c_init(clk_gpio, data_gpio); /* Initialize the GPIO pin for the i2c Clock Register */ - g_i2cClkGPIOMuxReg = GPIO_MUX; - g_i2cClkGPIODataReg = GPIO_DATA; - g_i2cClkGPIODataDirReg = GPIO_DATA_DIRECTION; + sw_i2c_clk_gpio_mux_reg = GPIO_MUX; + sw_i2c_clk_gpio_data_reg = GPIO_DATA; + sw_i2c_clk_gpio_data_dir_reg = GPIO_DATA_DIRECTION; /* Initialize the Clock GPIO Offset */ - g_i2cClockGPIO = i2cClkGPIO; + sw_i2c_clk_gpio = clk_gpio; /* Initialize the GPIO pin for the i2c Data Register */ - g_i2cDataGPIOMuxReg = GPIO_MUX; - g_i2cDataGPIODataReg = GPIO_DATA; - g_i2cDataGPIODataDirReg = GPIO_DATA_DIRECTION; + sw_i2c_data_gpio_mux_reg = GPIO_MUX; + sw_i2c_data_gpio_data_reg = GPIO_DATA; + sw_i2c_data_gpio_data_dir_reg = GPIO_DATA_DIRECTION; /* Initialize the Data GPIO Offset */ - g_i2cDataGPIO = i2cDataGPIO; + sw_i2c_data_gpio = data_gpio; /* Enable the GPIO pins for the i2c Clock and Data (GPIO MUX) */ - POKE32(g_i2cClkGPIOMuxReg, - PEEK32(g_i2cClkGPIOMuxReg) & ~(1 << g_i2cClockGPIO)); - POKE32(g_i2cDataGPIOMuxReg, - PEEK32(g_i2cDataGPIOMuxReg) & ~(1 << g_i2cDataGPIO)); + POKE32(sw_i2c_clk_gpio_mux_reg, + PEEK32(sw_i2c_clk_gpio_mux_reg) & ~(1 << sw_i2c_clk_gpio)); + POKE32(sw_i2c_data_gpio_mux_reg, + PEEK32(sw_i2c_data_gpio_mux_reg) & ~(1 << sw_i2c_data_gpio)); /* Enable GPIO power */ enableGPIO(1); /* Clear the i2c lines. */ for (i = 0; i < 9; i++) - swI2CStop(); + sw_i2c_stop(); return 0; } @@ -436,36 +442,36 @@ long swI2CInit( * This function reads the slave device's register * * Parameters: - * deviceAddress - i2c Slave device address which register + * addr - i2c Slave device address which register * to be read from - * registerIndex - Slave device's register to be read + * reg - Slave device's register to be read * * Return Value: * Register value */ -unsigned char swI2CReadReg( - unsigned char deviceAddress, - unsigned char registerIndex +unsigned char sm750_sw_i2c_read_reg( + unsigned char addr, + unsigned char reg ) { unsigned char data; /* Send the Start signal */ - swI2CStart(); + sw_i2c_start(); /* Send the device address */ - swI2CWriteByte(deviceAddress); + sw_i2c_write_byte(addr); /* Send the register index */ - swI2CWriteByte(registerIndex); + sw_i2c_write_byte(reg); /* Get the bus again and get the data from the device read address */ - swI2CStart(); - swI2CWriteByte(deviceAddress + 1); - data = swI2CReadByte(1); + sw_i2c_start(); + sw_i2c_write_byte(addr + 1); + data = sw_i2c_read_byte(1); /* Stop swI2C and release the bus */ - swI2CStop(); + sw_i2c_stop(); return data; } @@ -474,37 +480,37 @@ unsigned char swI2CReadReg( * This function writes a value to the slave device's register * * Parameters: - * deviceAddress - i2c Slave device address which register + * addr - i2c Slave device address which register * to be written - * registerIndex - Slave device's register to be written + * reg - Slave device's register to be written * data - Data to be written to the register * * Result: * 0 - Success * -1 - Fail */ -long swI2CWriteReg( - unsigned char deviceAddress, - unsigned char registerIndex, +long sm750_sw_i2c_write_reg( + unsigned char addr, + unsigned char reg, unsigned char data ) { - long returnValue = 0; + long ret = 0; /* Send the Start signal */ - swI2CStart(); + sw_i2c_start(); /* Send the device address and read the data. All should return success in order for the writing processed to be successful */ - if ((swI2CWriteByte(deviceAddress) != 0) || - (swI2CWriteByte(registerIndex) != 0) || - (swI2CWriteByte(data) != 0)) { - returnValue = -1; + if ((sw_i2c_write_byte(addr) != 0) || + (sw_i2c_write_byte(reg) != 0) || + (sw_i2c_write_byte(data) != 0)) { + ret = -1; } /* Stop i2c and release the bus */ - swI2CStop(); + sw_i2c_stop(); - return returnValue; + return ret; } |