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Updated the LCD SPI

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Now that I know a bit more about how SPI is working on the STM32F4
I removed the egregious hack and replaced it with some cleaner code
for driving the LCD. On the positive side it gets a faster update
rate on the screen.
This commit is contained in:
Chuck McManis
2015-01-25 17:57:19 -08:00
committed by Piotr Esden-Tempski
parent b76c30cdb0
commit 5379525a87
1 changed files with 10 additions and 33 deletions
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43
examples/stm32/f4/stm32f429i-discovery/lcd-serial/lcd-spi.c
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@@ -115,29 +115,15 @@ static void lcd_command(uint8_t cmd, int delay, int n_args,
*/
static void
lcd_command(uint8_t cmd, int delay, int n_args, const uint8_t *args) {
uint32_t timeout;
int i;
gpio_clear(GPIOC, GPIO2); // Select the LCD
rx_pend++;
spi_send(SPI5, cmd);
/* We need to wait until it is sent, if we turn on the Data
* line too soon, it ends up confusing the display to thinking
* its a data transfer, as it samples the D/CX line on the last
* bit sent.
*/
for (timeout = 0; (timeout < 1000) && (rx_pend); timeout++);
rx_pend = 0; // sometimes, at 10Mhz we miss this
(void) spi_xfer(LCD_SPI, cmd);
if (n_args) {
gpio_set(GPIOD, GPIO13); // Set the D/CX pin
for (i = 0; i < n_args; i++) {
rx_pend++;
spi_send(SPI5, *(args+i));
(void) spi_xfer(LCD_SPI, *(args+i));
}
/* This wait so that we don't pull CS too soon after
* sending the last byte of data.
*/
for (timeout = 0; (timeout < 1000) && (rx_pend); timeout++);
}
gpio_set(GPIOC, GPIO2); // Turn off chip select
gpio_clear(GPIOD, GPIO13); // always reset D/CX
@@ -341,7 +327,6 @@ void lcd_show_frame(void) {
*/
void
lcd_spi_init(void) {
uint32_t tmp;
/*
* Set up the GPIO lines for the SPI port and
@@ -360,24 +345,16 @@ lcd_spi_init(void) {
rx_pend = 0;
/* Implement state management hack */
nvic_enable_irq(NVIC_SPI5_IRQ);
// nvic_enable_irq(NVIC_SPI5_IRQ);
rcc_periph_clock_enable(RCC_SPI5);
/* This should configure SPI5 as we need it configured */
tmp = SPI_SR(LCD_SPI);
SPI_CR2(LCD_SPI) |= (SPI_CR2_SSOE | SPI_CR2_RXNEIE);
/* device clocks on the rising edge of SCK with MSB first */
tmp = SPI_CR1_BAUDRATE_FPCLK_DIV_4 | // 10.25Mhz SPI Clock (42M/4)
SPI_CR1_MSTR | // Master Mode
SPI_CR1_BIDIOE | // Write Only
SPI_CR1_SPE; // Enable SPI
SPI_CR1(LCD_SPI) = tmp; // Do it.
if (SPI_SR(LCD_SPI) & SPI_SR_MODF) {
SPI_CR1(LCD_SPI) = tmp; // Re-writing will reset MODF
console_puts("Initial mode fault.\n");
}
spi_init_master(LCD_SPI, SPI_CR1_BAUDRATE_FPCLK_DIV_4,
SPI_CR1_CPOL_CLK_TO_0_WHEN_IDLE,
SPI_CR1_CPHA_CLK_TRANSITION_1,
SPI_CR1_DFF_8BIT,
SPI_CR1_MSBFIRST);
spi_enable_ss_output(LCD_SPI);
spi_enable(LCD_SPI);
/* Set up the display */
console_puts("Initialize the display.\n");