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i.MX6 UART: Update periperal clock logic; Remove use of UART bits from i.MX1 that don't exist in i.MX6

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This commit is contained in:
Gregory Nutt 2016-03-07 14:08:53 -06:00
parent 912008a883
commit 3b1812b50f
4 changed files with 44 additions and 18 deletions
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2
arch/arm/src/imx6/Make.defs
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@ -133,4 +133,4 @@ CHIP_ASRCS =
# i.MX6-specific C source files
CHIP_CSRCS = imx_boot.c imx_memorymap.c imx_irq.c
CHIP_CSRCS = imx_gpio.c imx_iomuxc.c imx_serial.c # imx_lowputc.c
CHIP_CSRCS = imx_gpio.c imx_iomuxc.c imx_serial.c imx_lowputc.c

2
arch/arm/src/imx6/chip/imx_uart.h
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@ -183,7 +183,7 @@
/* UART Control Register 1 */
#define UART_UCR1_UARTEN (1 << 0) /* Bit 0: Enable/disable uart */
#define UART_UCR1_UARTEN (1 << 0) /* Bit 0: Enable/disable UART */
#define UART_UCR1_DOZE (1 << 1) /* Bit 1: UART Doze enable */
#define UART_UCR1_ATDMAEN (1 << 2) /* Bit 2: Aging DMA Timer Enable */
#define UART_UCR1_TXDMAEN (1 << 3) /* Bit 3: Transmitter Ready DMA Enable */

51
arch/arm/src/imx6/imx_lowputc.c
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@ -54,6 +54,7 @@
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Configuration ************************************************************/
#ifdef IMX_HAVE_UART_CONSOLE
# if defined(CONFIG_UART1_SERIAL_CONSOLE)
@ -89,6 +90,39 @@
# endif
#endif
/* Clocking *****************************************************************/
/* the UART module receives two clocks, a peripheral_clock (ipg_clk) and the
* module_clock (ipg_perclk). The peripheral_clock is used as write clock
* of the TxFIFO, read clock of the RxFIFO and synchronization of the modem
* control input pins. It must always be running when UART is enabled.
*
* The default ipg_clk is 66MHz (max 66.5MHz). ipg_clk is gated by
* CCGR5[CG12], uart_clk_enable. ipg_clk is shared among many modules and
* should not be controlled by the UART logic.
*
* The module_clock is for all the state machines, writing RxFIFO, reading
* TxFIFO, etc. It must always be running when UART is sending or receiving
* characters.This clock is used in order to allow frequency scaling on
* peripheral_clock without changing configuration of baud rate.
*
* The default ipg_perclk is 80MHz (max 80MHz). ipg_clk is gated by
* CCGR5[CG13], uart_serial_clk_enable. The clock generation sequence is:
*
* pll3_sw_clk (480M) -> CCGR5[CG13] -> 3 bit divider cg podf=6 ->
* PLL3_80M (80Mhz) -> CDCDR1: uart_clk_podf ->
* 6 bit divider default=1 -> UART_CLK_ROOT
*
* REVISIT: This logic assumes that all dividers are at the default value
* and that the value of the ipg_perclk is 80MHz.
*/
#define IPG_PERCLK_FREQUENCY 80000000
/* The BRM sub-block receives ref_clk (module_clock clock after divider).
* From this clock, and with integer and non-integer division, BRM generates
* a 16x baud rate clock.
*/
/****************************************************************************
* Private Data
****************************************************************************/
@ -318,9 +352,7 @@ int imx_uart_configure(uint32_t base, FAR const struct uart_config_s *config)
}
#endif
/* i.MX reference clock (PERCLK1) is configured for 16MHz */
putreg32(regval | UART_UCR4_REF16, base + UART_UCR4_OFFSET);
putreg32(regval, base + UART_UCR4_OFFSET);
/* Setup the new UART configuration */
@ -328,16 +360,17 @@ int imx_uart_configure(uint32_t base, FAR const struct uart_config_s *config)
/* Set the baud.
*
* buad = REFFREQ / (16 x NUM/DEM)
* baud * 16 / REFFREQ = NUM/DEN
* UBIR = NUM-1;
* UMBR = DEN-1
* REFFREQ = PERCLK1 / DIV
* REFFREQ = PERCLK1 / DIV, DIV=1..7
* DIV = RFDIV[2:0]
*
* First, select a closest value we can for the divider
*/
div = (BOARD_PERCLK1_FREQUENCY >> 4) / config->baud;
div = (IPG_PERCLK_FREQUENCY >> 4) / config->baud;
if (div > 7)
{
div = 7;
@ -353,7 +386,7 @@ int imx_uart_configure(uint32_t base, FAR const struct uart_config_s *config)
*/
num = config->baud;
den = (BOARD_PERCLK1_FREQUENCY << 4) / div;
den = (IPG_PERCLK_FREQUENCY << 4) / div;
if (num > den)
{
@ -431,12 +464,6 @@ int imx_uart_configure(uint32_t base, FAR const struct uart_config_s *config)
ucr2 |= (UART_UCR2_TXEN | UART_UCR2_RXEN);
putreg32(ucr2, base + UART_UCR2_OFFSET);
/* Enable the UART */
regval = getreg32(base + UART_UCR1_OFFSET);
regval |= UART_UCR1_UARTCLEN;
putreg32(regval, base + UART_UCR1_OFFSET);
#endif
return OK;

1
arch/arm/src/imx6/imx_serial.c
View File

@ -557,7 +557,6 @@ static int imx_setup(struct uart_dev_s *dev)
/* Initialize the UCR1 shadow register */
priv->ucr1 = imx_serialin(priv, UART_UCR1_OFFSET);
return ret;
#else