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Add PWM backlight control to Nokia6610GE8

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Add PWM backlight control to Nokia6610GE8 for the Olimex SAM7EX256
board.
This commit is contained in:
Andrew Hannam 2013-03-04 19:56:46 +10:00
parent 911df31d1c
commit 2d7c95d20a
1 changed files with 238 additions and 196 deletions
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56
drivers/gdisp/Nokia6610GE8/gdisp_lld_board_olimexsam7ex256.h
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@ -32,11 +32,31 @@
// ******************************************************
// Pointers to AT91SAM7X256 peripheral data structures
// ******************************************************
volatile AT91PS_PIO pPIOA = AT91C_BASE_PIOA;
volatile AT91PS_PIO pPIOB = AT91C_BASE_PIOB;
volatile AT91PS_SPI pSPI = AT91C_BASE_SPI0;
volatile AT91PS_PMC pPMC = AT91C_BASE_PMC;
volatile AT91PS_PDC pPDC = AT91C_BASE_PDC_SPI0;
static volatile AT91PS_PIO pPIOA = AT91C_BASE_PIOA;
static volatile AT91PS_PIO pPIOB = AT91C_BASE_PIOB;
static volatile AT91PS_SPI pSPI = AT91C_BASE_SPI0;
static volatile AT91PS_PMC pPMC = AT91C_BASE_PMC;
static volatile AT91PS_PDC pPDC = AT91C_BASE_PDC_SPI0;
/* The PWM backlight control is non-linear on this board.
* We pick values here that make it look a bit more linear.
*/
#define PWM_TOP_VALUE 500
#define PWM_BOTTOM_VALUE 200
#define PWM_VALUE(x) (PWM_BOTTOM_VALUE+(PWM_TOP_VALUE-PWM_BOTTOM_VALUE)*(x)/100)
/* PWM configuration structure. The LCD Backlight is on PWM1/PB20 ie PWM2/PIN1 in ChibiOS speak */
static const PWMConfig pwmcfg = {
1000000, /* 1 MHz PWM clock frequency. Ignored as we are using PWM_MCK_DIV_n */
1000, /* PWM period is 1000 cycles. */
NULL,
{
{PWM_MCK_DIV_1 | PWM_OUTPUT_ACTIVE_HIGH | PWM_OUTPUT_PIN1 | PWM_DISABLEPULLUP_PIN1, NULL},
},
};
static bool_t pwmRunning = FALSE;
/**
* @brief Initialise the board for the display.
@ -99,6 +119,10 @@ static __inline void init_board(void) {
//pSPI->SPI_CSR[0] = 0x01010C11; //9bit, CPOL=1, ClockPhase=0, SCLK = 48Mhz/32*12 = 125kHz
pSPI->SPI_CSR[0] = 0x01010311; //9bit, CPOL=1, ClockPhase=0, SCLK = 48Mhz/8 = 6MHz if using commented MR line above
/* Display backlight control at 100% */
pwmRunning = FALSE;
palSetPad(IOPORT2, PIOB_LCD_BL);
}
/**
@ -126,10 +150,28 @@ static __inline void setpin_reset(bool_t state) {
* @notapi
*/
static __inline void set_backlight(uint8_t percent) {
if (percent)
if (percent == 100) {
/* Turn the pin on - No PWM */
if (pwmRunning) {
pwmStop(&PWMD2);
pwmRunning = FALSE;
}
palSetPad(IOPORT2, PIOB_LCD_BL);
else
} else if (percent == 0) {
/* Turn the pin off - No PWM */
if (pwmRunning) {
pwmStop(&PWMD2);
pwmRunning = FALSE;
}
palClearPad(IOPORT2, PIOB_LCD_BL);
} else {
/* Use the PWM */
if (!pwmRunning) {
pwmStart(&PWMD2, &pwmcfg);
pwmRunning = TRUE;
}
pwmEnableChannel(&PWMD2, 0, PWM_VALUE(percent));
}
}
/**