📄 dloaduart.c
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/*====*====*====*====*====*====*====*====*====*====*====*====*====*====*====*
U A R T D R I V E R
GENERAL DESCRIPTION
This module contains a very simple-minded polling UART driver
for the DMSS boot downloader facility. This version supports
the MSM 3.0 UART.
EXTERNALIZED FUNCTIONS
dload_uart_init
Initializes the UART for transmit and receive.
uart_receive_byte
Receives a single byte from the UART.
uart_transmit_byte
Transmits a single byte to the UART.
INITIALIZATION AND SEQUENCING REQUIREMENTS
All necessary initialization for normal CPU operation must have
been performed before entering this module. dload_uart_init() should
be called before any other functions.
Copyright (c) 1995,1996,1997,1998,1999 by QUALCOMM Incorporated.
All Rights Reserved.
*====*====*====*====*====*====*====*====*====*====*====*====*====*====*====*/
/*===========================================================================
EDIT HISTORY FOR FILE
This section contains comments describing changes made to the module.
Notice that changes are listed in reverse chronological order.
$Header: L:/src/asw/MSM5105/vcs/dloaduart.c_v 1.9 22 Mar 2001 09:26:28 robertom $
when who what, where, why
-------- --- ----------------------------------------------------------
03/21/01 rmd In dload_uart_init(), replaced call to clk_rgm_sel() with the
code inside the function to avoid dependency to code outside
the boot code memory area.
03/21/01 rmd Moved the micro clock switching code from dload_uart_init()
to boot_downloader() to make sure that the wait states get
updated at the right time.
02/22/01 rmd In dload_uart_init(), Added clk_regime_set_mclk_tcxo() to
support MSM5100.
02/12/01 rmd In dload_uart_init(), replaced clk_regime_switch_mclk_to_tcxo
with mclk_switching_throttle() and eliminated call to
clk_regime_init.
12/04/00 rmd Modified clk_rgm_sel() call. this function uses
a parameter of type clk_regime_clk_sel_type to recognize
which clk source we want to initialize.
11/23/00 et changed MSM_OUTHM to clk_rgm_sel for the new clock API changes
11/22/00 rmd Added clk_regime_switch_mclk_to_tcxo() call into dloaduart_init()
to switch MCLK source from 4/3 TCXO to TCXO before we get to
download mode.
09/03/00 rmd Selecting TCXO/4 clock to drive UART in MSM_CLK_CTL5_WH
08/31/00 jcw Merge of MSM5000 and MSM3300 versions
08/28/00 rmd Replaced KICK_WATCHDOG with BOOTHW_KICK_WATCHDOG.
04/06/00 hrk Selecting TCXO/4 clock to drive UART in MSM_CLK_CTL5_WH
03/31/00 hrk Selecting TCXO clock to drive RXDSP in MSM_CLK_CTL5_WH
09/13/99 lcc Merged from MSM5000PLT archive:
1. Changes to support UART clocks for MSM5000
2. Checkin of changes for initial port to MSM5000
3. Made changes necessary so that the uart drivers will work
under MSM5000. MR1, TFWR, RFWR and IPR register changed in width
as result of the increase in FIFO size.
08/11/99 kk Merge from SS baseline.
03/17/99 ms Renamed bb_uart_init to dload_uart_init
due to Virtual Boot Block changes.
08/08/98 hcg Removed inline asm polling loop - Moved some stuff to header files.
07/26/98 hcg Revised for coding standard, removed unused code
06/01/98 hcg Ported from Flashprg by ptw
===========================================================================*/
/*===========================================================================
INCLUDE FILES FOR MODULE
===========================================================================*/
#include "dloaduart.h"
dword MSM_image_H[ MSM_MAX_INX ];
/*-------------------------------------------------------------------------*/
/*===========================================================================
FUNCTION uart_drain
DESCRIPTION
This function waits for the last character in the UART's transmit
FIFO to be transmitted. This allows the caller to be sure that all
characters are transmitted.
DEPENDENCIES
If the transmit FIFO is not empty, the UART must be initialized enough
for it to eventually empty itself, or else this routine will wait
forever.
RETURN VALUE
None.
SIDE EFFECTS
The watchdog is reset.
===========================================================================*/
void uart_drain(void)
{
/*- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -*/
/* Wait while the UART's transmitter drains. This lets the ACK to
the GO command that started FLASHPRG get back to the PC before
we reset the UART. */
while ( ( inp(UART_SR) & UART_SR_TXEMT ) == 0)
{
BOOTHW_KICK_WATCHDOG(); /* Don't let the watchdog expire while we wait */
}
}/* uart_drain() */
/*===========================================================================
FUNCTION dload_uart_init
DESCRIPTION
This function initializes the MSM 3000 UART to 115,200 bps, 8N1, with
no interrupts enabled but both receiver and transmitter running.
Before initializing the UART, this function waits for the UART's
transmit buffer to empty out. This permits the ACK to the GO
command that started the program (or any other pending transmission)
to get back to the host, instead of being lost when the UART is
reset.
DEPENDENCIES
If the transmit FIFO is not empty, the UART must be initialized enough
for it to eventually empty itself, or else this routine will wait
forever.
RETURN VALUE
None.
SIDE EFFECTS
The watchdog is reset.
===========================================================================*/
void dload_uart_init(word baud_rate)
{
int chr; /* character variable for RX FIFO drain */
/*- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -*/
/* Code copied from clk_rgm_sel(). We do not want to depend on code outside
the boot code memory area. */
MSM_OUTHM( UART_CLK_SEL_REG, UART_CLK_SEL_M, UART_CLK_SEL_TCXO4);
/* drain anything in the UART */
uart_drain();
(void) MSMU_OUT(UART_MVR, UART_MVR_V); /* M register LSB */
(void) MSMU_OUT(UART_NVR, UART_NVR_V); /* N register LSB */
(void) MSMU_OUT(UART_DVR, UART_DVR_V); /* D register LSB */
(void) MSMU_OUT(UART_MNDR, UART_MNDR_V); /* MSBs of M, N, and D */
(void) MSMU_OUT(UART_IMR, 0); /* Mask all interrupts off */
/* Receive watermark at zero. This means an interrupt would be generated
* whenever any (more than zero) characters are in the Rx FIFO. Since we
* don't use Rx interrupts, this doesn't really matter.
*/
(void) MSMU_RXWAT_OUT(0);
/* Transmit watermark. We DO use this, to determine if there is
* room for one more character in the Tx FIFO.
*/
(void) MSMU_TXWAT_OUT(UART_TXWAT_VAL);
/* Do not enable hardware flow control. It works, but it causes
* more trouble than it's worth with improperly-wired cables.
* There's really no need for it anyway, since the main data flow
* is from the host to the phone, and the phone (having nothing
* better to do than service the UART) will always keep up.
*/
(void) MSMU_MR1_OUT(0);
(void) MSMU_OUT(UART_MR2, UART_MR2_8BPC | UART_MR2_1SB); /* 8N1 */
//switch(baud_rate)
//{
// case UART_1152K_BPS:
(void) MSMU_OUT(UART_CSR, UART_CSR_1152K_BPS); /* 115,200 baud rate */
// break;
//case UART_2304K_BPS:
// (void) MSMU_OUT(UART_CSR, UART_CSR_2304K_BPS); /* 230,400 baud rate */
// break;
//case UART_4608K_BPS:
// (void) MSMU_OUT(UART_CSR, UART_CSR_4608K_BPS); /* 460,800 baud rate */
// break;
//default:
// (void) MSMU_OUT(UART_CSR, UART_CSR_1152K_BPS); /* 115,200 baud rate */
//}
//(void) MSMU_OUT(UART_CSR, UART_CSR_1152K_BPS); /* 115,200 baud rate */
(void) MSMU_OUT(UART_CR, UART_CR_RESET_ERR); /* Reset error status */
(void) MSMU_OUT(UART_CR, UART_CR_RESET_RX); /* Reset the receiver */
(void) MSMU_OUT(UART_CR, UART_CR_RESET_RX); /* Reset the receiver */
(void) MSMU_OUT(UART_CR, UART_CR_RESET_TX); /* Reset the transmitter */
(void) MSMU_OUT(UART_CR, UART_CR_RESET_TX); /* Reset the transmitter */
(void) MSMU_OUT(UART_CR, UART_CR_RX_ENA); /* Enable the receiver */
(void) MSMU_OUT(UART_CR, UART_CR_TX_ENA); /* Enable the transmitter */
/* Wait while the UART's reciever drains. After resetting the UART, we
* may have a couple of spurrious characters in the RX FIFO. This can
* happen especially when the phone is not plugged into a DIP, thus
* causing the UART to re-recognize the start of break condtion.
*/
while ( ( inp(UART_SR) & UART_SR_RXRDY ) != 0)
{
chr = inp(UART_RFIFO); /* Get the received character */
BOOTHW_KICK_WATCHDOG(); /* Don't let the watchdog expire while we wait */
}
} /* dload_uart_init() */
/*===========================================================================
FUNCTION dload_uart_poll
DESCRIPTION
This function polls the UART for the presence of recieved data
DEPENDENCIES
The UART must be initialized and enabled, or else this routine will
wait forever.
RETURN VALUE
If the RXRDY bit goes high (indicating the presence of data), we return
the entire status register. If timeout_enabled is true, we only wait for
a few seconds. Otherwise, we will wait forever for data to arrive
SIDE EFFECTS
The watchdog timer will be kicked _very_ often.
===========================================================================*/
int dload_uart_poll(boolean timeout_enabled)
{
int status;
int countdown;
/* if we're going to have a timeout */
if (timeout_enabled)
{
/* only loop a limited number of times */
for (countdown = 1000000; countdown > 0; countdown--)
{
/* for each loop, get the status, and return it if data is present */
status = inp(UART_SR);
if ( (status & UART_SR_RXRDY) != 0)
return status;
/* kick the watchdog periodically */
BOOTHW_KICK_WATCHDOG();
}
return UART_TIMEOUT;
}
else
/* loop forever waiting for data */
for (;;)
{
/* for each loop, get the status, and return it if data is present */
status = inp(UART_SR);
if ( (status & UART_SR_RXRDY) != 0)
return status;
/* kick the watchdog periodically */
BOOTHW_KICK_WATCHDOG();
}
} /* dload_uart_poll() */
/*===========================================================================
FUNCTION uart_receive_byte
DESCRIPTION
This function receives a single byte from the UART by polling.
DEPENDENCIES
The UART must be initialized and enabled, or else this routine will
wait forever.
RETURN VALUE
If a character is received without error, returns the value of the
character received. If an error occurs, returns UART_RX_ERR. If a
timeout occurs, returns UART_TIMEOUT.
SIDE EFFECTS
===========================================================================*/
int uart_receive_byte(void)
{
int status;
/* Return value from the UART's status register */
int chr;
/* The character received from the UART */
static boolean init_boot = TRUE;
/*- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -*/
/* poll the UART to receive a character if it is the initial
* communication with the PST we need to enable a timeout of 3 seconds.
* otherwise, simply poll the UART indefinitely
*/
if (init_boot)
{
status = dload_uart_poll(TIMEOUT_ENABLED);
}
else
{
status = dload_uart_poll(TIMEOUT_DISABLED);
}
/* a timeout has occurred, return error */
if ( (status == UART_TIMEOUT) && init_boot)
return UART_TIMEOUT;
/* There are three types of errors we can detect here: Parity/Framing,
* Break, and Overrun. For a overrun, we just clear the error. For
* parity/framing errors, we throw away that character. For a break, we
* ignore it. We basically ignore conditions we can't do anything about.
*/
if ((status & UART_SR_BREAK_RXD) != 0)
{
chr = inp(UART_RFIFO);
return UART_RX_ERR;
}
/* Check for an overrun error -- if one occurs, there isn't anything
* we can do about it. So, we'll just clear the error condition. Since
* this is character mode, the only other error we could be clearing is
* the hunt character, which we should never get.
*/
/* if ((status & UART_SR_OVR_ERR) != 0)
(void) MSMU_OUT(UART_CR, UART_CR_RESET_ERR);*/
/* Check for parity framing error -- if one occurs, discard the character
* and return an error. We can't trust that this character is valid. It
* might even be because of a break, so we leave init_boot true (or it's
* current state, at least).
*/
if ((status & UART_SR_PF_ERR) != 0)
{
chr = inp(UART_RFIFO);
return UART_RX_ERR;
}
/* Get the received character */
chr = inp(UART_RFIFO);
init_boot = FALSE;
return chr; /* All OK, return the received character */
} /* uart_receive_byte() */
/*===========================================================================
FUNCTION uart_transmit_byte
DESCRIPTION
This function transmits a single byte through the UART.
DEPENDENCIES
The UART transmitter must be initialized and enabled, or this routine
will wait forever.
RETURN VALUE
None.
SIDE EFFECTS
The watchdog may be reset.
===========================================================================*/
void uart_transmit_byte
(
byte chr
/* Character to be transmitted */
)
{
/*- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -*/
/* Wait until the transmit FIFO is not too full */
while ((inp(UART_ISR) & UART_ISR_TXLEV) == 0)
{
/* Don't let the watchdog expire while we wait */
BOOTHW_KICK_WATCHDOG();
}
/* Put the byte into the Tx FIFO */
(void) MSMU_OUT(UART_TFIFO, (int) chr);
} /* uart_transmit_byte() */
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