msm_serial: Make baud_code detection more dynamic
Currently msm_set_baud_rate() assumes the uart clock rate is 1.8432 MHz. This is not always true, and limits our options to program the baud rate. Instead of assuming the rate and hard-coding the baud_code based on it, calculate the divider that we want and try to find the closest baud_code that matches. This allows us to support uarts with faster clock speeds. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Acked-by: David Brown <davidb@codeaurora.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Stephen Boyd
Greg Kroah-Hartman
Родитель
f8fb952fd4
Коммит
6909dadd91
|
|
@ -322,70 +322,60 @@ static void msm_break_ctl(struct uart_port *port, int break_ctl)
|
|||
msm_write(port, UART_CR_CMD_STOP_BREAK, UART_CR);
|
||||
}
|
||||
|
||||
struct msm_baud_map {
|
||||
u16 divisor;
|
||||
u8 code;
|
||||
u8 rxstale;
|
||||
};
|
||||
|
||||
static const struct msm_baud_map *
|
||||
msm_find_best_baud(struct uart_port *port, unsigned int baud)
|
||||
{
|
||||
unsigned int i, divisor;
|
||||
const struct msm_baud_map *entry;
|
||||
static const struct msm_baud_map table[] = {
|
||||
{ 1536, 0x00, 1 },
|
||||
{ 768, 0x11, 1 },
|
||||
{ 384, 0x22, 1 },
|
||||
{ 192, 0x33, 1 },
|
||||
{ 96, 0x44, 1 },
|
||||
{ 48, 0x55, 1 },
|
||||
{ 32, 0x66, 1 },
|
||||
{ 24, 0x77, 1 },
|
||||
{ 16, 0x88, 1 },
|
||||
{ 12, 0x99, 6 },
|
||||
{ 8, 0xaa, 6 },
|
||||
{ 6, 0xbb, 6 },
|
||||
{ 4, 0xcc, 6 },
|
||||
{ 3, 0xdd, 8 },
|
||||
{ 2, 0xee, 16 },
|
||||
{ 1, 0xff, 31 },
|
||||
};
|
||||
|
||||
divisor = uart_get_divisor(port, baud);
|
||||
|
||||
for (i = 0, entry = table; i < ARRAY_SIZE(table); i++, entry++)
|
||||
if (entry->divisor <= divisor)
|
||||
break;
|
||||
|
||||
return entry; /* Default to smallest divider */
|
||||
}
|
||||
|
||||
static int msm_set_baud_rate(struct uart_port *port, unsigned int baud)
|
||||
{
|
||||
unsigned int baud_code, rxstale, watermark;
|
||||
unsigned int rxstale, watermark;
|
||||
struct msm_port *msm_port = UART_TO_MSM(port);
|
||||
const struct msm_baud_map *entry;
|
||||
|
||||
switch (baud) {
|
||||
case 300:
|
||||
baud_code = UART_CSR_300;
|
||||
rxstale = 1;
|
||||
break;
|
||||
case 600:
|
||||
baud_code = UART_CSR_600;
|
||||
rxstale = 1;
|
||||
break;
|
||||
case 1200:
|
||||
baud_code = UART_CSR_1200;
|
||||
rxstale = 1;
|
||||
break;
|
||||
case 2400:
|
||||
baud_code = UART_CSR_2400;
|
||||
rxstale = 1;
|
||||
break;
|
||||
case 4800:
|
||||
baud_code = UART_CSR_4800;
|
||||
rxstale = 1;
|
||||
break;
|
||||
case 9600:
|
||||
baud_code = UART_CSR_9600;
|
||||
rxstale = 2;
|
||||
break;
|
||||
case 14400:
|
||||
baud_code = UART_CSR_14400;
|
||||
rxstale = 3;
|
||||
break;
|
||||
case 19200:
|
||||
baud_code = UART_CSR_19200;
|
||||
rxstale = 4;
|
||||
break;
|
||||
case 28800:
|
||||
baud_code = UART_CSR_28800;
|
||||
rxstale = 6;
|
||||
break;
|
||||
case 38400:
|
||||
baud_code = UART_CSR_38400;
|
||||
rxstale = 8;
|
||||
break;
|
||||
case 57600:
|
||||
baud_code = UART_CSR_57600;
|
||||
rxstale = 16;
|
||||
break;
|
||||
case 115200:
|
||||
default:
|
||||
baud_code = UART_CSR_115200;
|
||||
baud = 115200;
|
||||
rxstale = 31;
|
||||
break;
|
||||
}
|
||||
entry = msm_find_best_baud(port, baud);
|
||||
|
||||
if (msm_port->is_uartdm)
|
||||
msm_write(port, UART_CR_CMD_RESET_RX, UART_CR);
|
||||
|
||||
msm_write(port, baud_code, UART_CSR);
|
||||
msm_write(port, entry->code, UART_CSR);
|
||||
|
||||
/* RX stale watermark */
|
||||
rxstale = entry->rxstale;
|
||||
watermark = UART_IPR_STALE_LSB & rxstale;
|
||||
watermark |= UART_IPR_RXSTALE_LAST;
|
||||
watermark |= UART_IPR_STALE_TIMEOUT_MSB & (rxstale << 2);
|
||||
|
|
|
|||
|
|
@ -38,19 +38,7 @@
|
|||
#define UART_MR2_PARITY_MODE_SPACE 0x3
|
||||
#define UART_MR2_PARITY_MODE 0x3
|
||||
|
||||
#define UART_CSR 0x0008
|
||||
#define UART_CSR_115200 0xFF
|
||||
#define UART_CSR_57600 0xEE
|
||||
#define UART_CSR_38400 0xDD
|
||||
#define UART_CSR_28800 0xCC
|
||||
#define UART_CSR_19200 0xBB
|
||||
#define UART_CSR_14400 0xAA
|
||||
#define UART_CSR_9600 0x99
|
||||
#define UART_CSR_4800 0x77
|
||||
#define UART_CSR_2400 0x55
|
||||
#define UART_CSR_1200 0x44
|
||||
#define UART_CSR_600 0x33
|
||||
#define UART_CSR_300 0x22
|
||||
#define UART_CSR 0x0008
|
||||
|
||||
#define UART_TF 0x000C
|
||||
#define UARTDM_TF 0x0070
|
||||
|
|
@ -152,6 +140,7 @@ static inline void msm_serial_set_mnd_regs_tcxo(struct uart_port *port)
|
|||
msm_write(port, 0xF1, UART_NREG);
|
||||
msm_write(port, 0x0F, UART_DREG);
|
||||
msm_write(port, 0x1A, UART_MNDREG);
|
||||
port->uartclk = 1843200;
|
||||
}
|
||||
|
||||
/*
|
||||
|
|
@ -163,6 +152,7 @@ static inline void msm_serial_set_mnd_regs_tcxoby4(struct uart_port *port)
|
|||
msm_write(port, 0xF6, UART_NREG);
|
||||
msm_write(port, 0x0F, UART_DREG);
|
||||
msm_write(port, 0x0A, UART_MNDREG);
|
||||
port->uartclk = 1843200;
|
||||
}
|
||||
|
||||
static inline
|
||||
|
|
@ -170,7 +160,7 @@ void msm_serial_set_mnd_regs_from_uartclk(struct uart_port *port)
|
|||
{
|
||||
if (port->uartclk == 19200000)
|
||||
msm_serial_set_mnd_regs_tcxo(port);
|
||||
else
|
||||
else if (port->uartclk == 4800000)
|
||||
msm_serial_set_mnd_regs_tcxoby4(port);
|
||||
}
|
||||
|
||||
|
|
|
|||
Загрузка…
Ссылка в новой задаче