* [PATCH 0/2] Perfect 8250 mtk uart function.
@ 2019-04-25 8:41 Long Cheng
2019-04-25 8:41 ` [PATCH 1/2] serial: 8250-mtk: add follow control Long Cheng
2019-04-25 8:41 ` [PATCH 2/2] serial: 8250-mtk: modify baudrate setting Long Cheng
0 siblings, 2 replies; 6+ messages in thread
From: Long Cheng @ 2019-04-25 8:41 UTC (permalink / raw)
To: Greg Kroah-Hartman
Cc: Jiri Slaby, Matthias Brugger, Long Cheng, Gustavo A. R. Silva,
Peter Shih, linux-serial, linux-arm-kernel, linux-mediatek,
linux-kernel, srv_heupstream, Yingjoe Chen, YT Shen, Zhenbao Liu,
Changqi Hu
Perfect 8250 mtk uart function,
1.Modify baudrate setting
2.Add follow control function
Long Cheng (2):
serial: 8250-mtk: add follow control
serial: 8250-mtk: modify baudrate setting
drivers/tty/serial/8250/8250_mtk.c | 162 +++++++++++++++++++++++++++++++------
1 file changed, 139 insertions(+), 23 deletions(-)
--
1.9.1
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH 1/2] serial: 8250-mtk: add follow control
2019-04-25 8:41 [PATCH 0/2] Perfect 8250 mtk uart function Long Cheng
@ 2019-04-25 8:41 ` Long Cheng
2019-04-25 10:40 ` Matthias Brugger
2019-04-28 17:40 ` Sean Wang
2019-04-25 8:41 ` [PATCH 2/2] serial: 8250-mtk: modify baudrate setting Long Cheng
1 sibling, 2 replies; 6+ messages in thread
From: Long Cheng @ 2019-04-25 8:41 UTC (permalink / raw)
To: Greg Kroah-Hartman
Cc: Jiri Slaby, Matthias Brugger, Long Cheng, Gustavo A. R. Silva,
Peter Shih, linux-serial, linux-arm-kernel, linux-mediatek,
linux-kernel, srv_heupstream, Yingjoe Chen, YT Shen, Zhenbao Liu,
Changqi Hu
Add SW and HW follow control function.
Signed-off-by: Long Cheng <long.cheng@mediatek.com>
---
drivers/tty/serial/8250/8250_mtk.c | 60 ++++++++++++++++++++++--------------
1 file changed, 37 insertions(+), 23 deletions(-)
diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c
index c1fdbc0..959fd85 100644
--- a/drivers/tty/serial/8250/8250_mtk.c
+++ b/drivers/tty/serial/8250/8250_mtk.c
@@ -21,12 +21,14 @@
#include "8250.h"
-#define UART_MTK_HIGHS 0x09 /* Highspeed register */
-#define UART_MTK_SAMPLE_COUNT 0x0a /* Sample count register */
-#define UART_MTK_SAMPLE_POINT 0x0b /* Sample point register */
+#define MTK_UART_HIGHS 0x09 /* Highspeed register */
+#define MTK_UART_SAMPLE_COUNT 0x0a /* Sample count register */
+#define MTK_UART_SAMPLE_POINT 0x0b /* Sample point register */
#define MTK_UART_RATE_FIX 0x0d /* UART Rate Fix Register */
-
#define MTK_UART_DMA_EN 0x13 /* DMA Enable register */
+#define MTK_UART_RXTRI_AD 0x14 /* RX Trigger address */
+#define MTK_UART_FRACDIV_L 0x15 /* Fractional divider LSB address */
+#define MTK_UART_FRACDIV_M 0x16 /* Fractional divider MSB address */
#define MTK_UART_DMA_EN_TX 0x2
#define MTK_UART_DMA_EN_RX 0x5
@@ -46,6 +48,7 @@ enum dma_rx_status {
struct mtk8250_data {
int line;
unsigned int rx_pos;
+ unsigned int clk_count;
struct clk *uart_clk;
struct clk *bus_clk;
struct uart_8250_dma *dma;
@@ -196,9 +199,15 @@ static void mtk8250_shutdown(struct uart_port *port)
mtk8250_set_termios(struct uart_port *port, struct ktermios *termios,
struct ktermios *old)
{
+ unsigned short fraction_L_mapping[] = {
+ 0, 1, 0x5, 0x15, 0x55, 0x57, 0x57, 0x77, 0x7F, 0xFF, 0xFF
+ };
+ unsigned short fraction_M_mapping[] = {
+ 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 3
+ };
struct uart_8250_port *up = up_to_u8250p(port);
+ unsigned int baud, quot, fraction;
unsigned long flags;
- unsigned int baud, quot;
#ifdef CONFIG_SERIAL_8250_DMA
if (up->dma) {
@@ -214,7 +223,7 @@ static void mtk8250_shutdown(struct uart_port *port)
serial8250_do_set_termios(port, termios, old);
/*
- * Mediatek UARTs use an extra highspeed register (UART_MTK_HIGHS)
+ * Mediatek UARTs use an extra highspeed register (MTK_UART_HIGHS)
*
* We need to recalcualte the quot register, as the claculation depends
* on the vaule in the highspeed register.
@@ -230,18 +239,11 @@ static void mtk8250_shutdown(struct uart_port *port)
port->uartclk / 16 / UART_DIV_MAX,
port->uartclk);
- if (baud <= 115200) {
- serial_port_out(port, UART_MTK_HIGHS, 0x0);
+ if (baud < 115200) {
+ serial_port_out(port, MTK_UART_HIGHS, 0x0);
quot = uart_get_divisor(port, baud);
- } else if (baud <= 576000) {
- serial_port_out(port, UART_MTK_HIGHS, 0x2);
-
- /* Set to next lower baudrate supported */
- if ((baud == 500000) || (baud == 576000))
- baud = 460800;
- quot = DIV_ROUND_UP(port->uartclk, 4 * baud);
} else {
- serial_port_out(port, UART_MTK_HIGHS, 0x3);
+ serial_port_out(port, MTK_UART_HIGHS, 0x3);
quot = DIV_ROUND_UP(port->uartclk, 256 * baud);
}
@@ -258,17 +260,29 @@ static void mtk8250_shutdown(struct uart_port *port)
/* reset DLAB */
serial_port_out(port, UART_LCR, up->lcr);
- if (baud > 460800) {
+ if (baud >= 115200) {
unsigned int tmp;
- tmp = DIV_ROUND_CLOSEST(port->uartclk, quot * baud);
- serial_port_out(port, UART_MTK_SAMPLE_COUNT, tmp - 1);
- serial_port_out(port, UART_MTK_SAMPLE_POINT,
- (tmp - 2) >> 1);
+ tmp = (port->uartclk / (baud * quot)) - 1;
+ serial_port_out(port, MTK_UART_SAMPLE_COUNT, tmp);
+ serial_port_out(port, MTK_UART_SAMPLE_POINT,
+ (tmp >> 1) - 1);
+
+ /*count fraction to set fractoin register */
+ fraction = ((port->uartclk * 100) / baud / quot) % 100;
+ fraction = DIV_ROUND_CLOSEST(fraction, 10);
+ serial_port_out(port, MTK_UART_FRACDIV_L,
+ fraction_L_mapping[fraction]);
+ serial_port_out(port, MTK_UART_FRACDIV_M,
+ fraction_M_mapping[fraction]);
} else {
- serial_port_out(port, UART_MTK_SAMPLE_COUNT, 0x00);
- serial_port_out(port, UART_MTK_SAMPLE_POINT, 0xff);
+ serial_port_out(port, MTK_UART_SAMPLE_COUNT, 0x00);
+ serial_port_out(port, MTK_UART_SAMPLE_POINT, 0xff);
+ serial_port_out(port, MTK_UART_FRACDIV_L, 0x00);
+ serial_port_out(port, MTK_UART_FRACDIV_M, 0x00);
}
+ if (uart_console(port))
+ up->port.cons->cflag = termios->c_cflag;
spin_unlock_irqrestore(&port->lock, flags);
/* Don't rewrite B0 */
--
1.7.9.5
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH 2/2] serial: 8250-mtk: modify baudrate setting
2019-04-25 8:41 [PATCH 0/2] Perfect 8250 mtk uart function Long Cheng
2019-04-25 8:41 ` [PATCH 1/2] serial: 8250-mtk: add follow control Long Cheng
@ 2019-04-25 8:41 ` Long Cheng
1 sibling, 0 replies; 6+ messages in thread
From: Long Cheng @ 2019-04-25 8:41 UTC (permalink / raw)
To: Greg Kroah-Hartman
Cc: Jiri Slaby, Matthias Brugger, Long Cheng, Gustavo A. R. Silva,
Peter Shih, linux-serial, linux-arm-kernel, linux-mediatek,
linux-kernel, srv_heupstream, Yingjoe Chen, YT Shen, Zhenbao Liu,
Changqi Hu
In termios function, add Fractional divider to adjust baudrate.
Signed-off-by: Long Cheng <long.cheng@mediatek.com>
---
drivers/tty/serial/8250/8250_mtk.c | 102 ++++++++++++++++++++++++++++++++++++
1 file changed, 102 insertions(+)
diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c
index 959fd85..417c7c8 100644
--- a/drivers/tty/serial/8250/8250_mtk.c
+++ b/drivers/tty/serial/8250/8250_mtk.c
@@ -25,13 +25,28 @@
#define MTK_UART_SAMPLE_COUNT 0x0a /* Sample count register */
#define MTK_UART_SAMPLE_POINT 0x0b /* Sample point register */
#define MTK_UART_RATE_FIX 0x0d /* UART Rate Fix Register */
+#define MTK_UART_ESCAPE_DAT 0x10 /* Escape Character register */
+#define MTK_UART_ESCAPE_EN 0x11 /* Escape Enable register */
#define MTK_UART_DMA_EN 0x13 /* DMA Enable register */
#define MTK_UART_RXTRI_AD 0x14 /* RX Trigger address */
#define MTK_UART_FRACDIV_L 0x15 /* Fractional divider LSB address */
#define MTK_UART_FRACDIV_M 0x16 /* Fractional divider MSB address */
+#define MTK_UART_IER_XOFFI 0x20 /* Enable XOFF character interrupt */
+#define MTK_UART_IER_RTSI 0x40 /* Enable RTS Modem status interrupt */
+#define MTK_UART_IER_CTSI 0x80 /* Enable CTS Modem status interrupt */
+
+#define MTK_UART_EFR_EN 0x10 /* Enable enhancement feature */
+#define MTK_UART_EFR_RTS 0x40 /* Enable hardware rx flow control */
+#define MTK_UART_EFR_CTS 0x80 /* Enable hardware tx flow control */
+#define MTK_UART_EFR_NO_SW_FC 0x0 /* no sw flow control */
+#define MTK_UART_EFR_XON1_XOFF1 0xa /* XON1/XOFF1 as sw flow control */
+#define MTK_UART_EFR_XON2_XOFF2 0x5 /* XON2/XOFF2 as sw flow control */
+#define MTK_UART_EFR_SW_FC_MASK 0xf /* Enable CTS Modem status interrupt */
+#define MTK_UART_EFR_HW_FC (MTK_UART_EFR_RTS | MTK_UART_EFR_CTS)
#define MTK_UART_DMA_EN_TX 0x2
#define MTK_UART_DMA_EN_RX 0x5
+#define MTK_UART_ESCAPE_CHAR 0x77 /* Escape char added under sw fc */
#define MTK_UART_TX_SIZE UART_XMIT_SIZE
#define MTK_UART_RX_SIZE 0x8000
#define MTK_UART_TX_TRIGGER 1
@@ -57,6 +72,13 @@ struct mtk8250_data {
#endif
};
+/* flow control mode */
+enum {
+ MTK_UART_FC_NONE,
+ MTK_UART_FC_SW,
+ MTK_UART_FC_HW,
+};
+
#ifdef CONFIG_SERIAL_8250_DMA
static void mtk8250_rx_dma(struct uart_8250_port *up);
@@ -195,6 +217,75 @@ static void mtk8250_shutdown(struct uart_port *port)
return serial8250_do_shutdown(port);
}
+static void mtk8250_disable_intrs(struct uart_8250_port *up, int mask)
+{
+ serial_out(up, UART_IER, serial_in(up, UART_IER) & (~mask));
+}
+
+static void mtk8250_enable_intrs(struct uart_8250_port *up, int mask)
+{
+ serial_out(up, UART_IER, serial_in(up, UART_IER) | mask);
+}
+
+static void mtk8250_set_flow_ctrl(struct uart_8250_port *up, int mode)
+{
+ struct uart_port *port = &up->port;
+ int lcr = serial_in(up, UART_LCR);
+
+ serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+ serial_out(up, UART_EFR, UART_EFR_ECB);
+ serial_out(up, UART_LCR, lcr);
+ lcr = serial_in(up, UART_LCR);
+
+ switch (mode) {
+ case MTK_UART_FC_NONE:
+ serial_out(up, MTK_UART_ESCAPE_DAT, MTK_UART_ESCAPE_CHAR);
+ serial_out(up, MTK_UART_ESCAPE_EN, 0x00);
+ serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+ serial_out(up, UART_EFR, serial_in(up, UART_EFR) &
+ (~(MTK_UART_EFR_HW_FC | MTK_UART_EFR_SW_FC_MASK)));
+ serial_out(up, UART_LCR, lcr);
+ mtk8250_disable_intrs(up, MTK_UART_IER_XOFFI |
+ MTK_UART_IER_RTSI | MTK_UART_IER_CTSI);
+ break;
+
+ case MTK_UART_FC_HW:
+ serial_out(up, MTK_UART_ESCAPE_DAT, MTK_UART_ESCAPE_CHAR);
+ serial_out(up, MTK_UART_ESCAPE_EN, 0x00);
+ serial_out(up, UART_MCR, UART_MCR_RTS);
+ serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+
+ /*enable hw flow control*/
+ serial_out(up, UART_EFR, MTK_UART_EFR_HW_FC |
+ (serial_in(up, UART_EFR) &
+ (~(MTK_UART_EFR_HW_FC | MTK_UART_EFR_SW_FC_MASK))));
+
+ serial_out(up, UART_LCR, lcr);
+ mtk8250_disable_intrs(up, MTK_UART_IER_XOFFI);
+ mtk8250_enable_intrs(up, MTK_UART_IER_CTSI | MTK_UART_IER_RTSI);
+ break;
+
+ case MTK_UART_FC_SW: /*MTK software flow control */
+ serial_out(up, MTK_UART_ESCAPE_DAT, MTK_UART_ESCAPE_CHAR);
+ serial_out(up, MTK_UART_ESCAPE_EN, 0x01);
+ serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+
+ /*enable sw flow control */
+ serial_out(up, UART_EFR, MTK_UART_EFR_XON1_XOFF1 |
+ (serial_in(up, UART_EFR) &
+ (~(MTK_UART_EFR_HW_FC | MTK_UART_EFR_SW_FC_MASK))));
+
+ serial_out(up, UART_XON1, START_CHAR(port->state->port.tty));
+ serial_out(up, UART_XOFF1, STOP_CHAR(port->state->port.tty));
+ serial_out(up, UART_LCR, lcr);
+ mtk8250_disable_intrs(up, MTK_UART_IER_CTSI|MTK_UART_IER_RTSI);
+ mtk8250_enable_intrs(up, MTK_UART_IER_XOFFI);
+ break;
+ default:
+ break;
+ }
+}
+
static void
mtk8250_set_termios(struct uart_port *port, struct ktermios *termios,
struct ktermios *old)
@@ -208,6 +299,7 @@ static void mtk8250_shutdown(struct uart_port *port)
struct uart_8250_port *up = up_to_u8250p(port);
unsigned int baud, quot, fraction;
unsigned long flags;
+ int mode;
#ifdef CONFIG_SERIAL_8250_DMA
if (up->dma) {
@@ -281,6 +373,16 @@ static void mtk8250_shutdown(struct uart_port *port)
serial_port_out(port, MTK_UART_FRACDIV_L, 0x00);
serial_port_out(port, MTK_UART_FRACDIV_M, 0x00);
}
+
+ if ((termios->c_cflag & CRTSCTS) && (!(termios->c_iflag & CRTSCTS)))
+ mode = MTK_UART_FC_HW;
+ else if (termios->c_iflag & CRTSCTS)
+ mode = MTK_UART_FC_SW;
+ else
+ mode = MTK_UART_FC_NONE;
+
+ mtk8250_set_flow_ctrl(up, mode);
+
if (uart_console(port))
up->port.cons->cflag = termios->c_cflag;
--
1.7.9.5
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH 1/2] serial: 8250-mtk: add follow control
2019-04-25 8:41 ` [PATCH 1/2] serial: 8250-mtk: add follow control Long Cheng
@ 2019-04-25 10:40 ` Matthias Brugger
2019-04-26 5:22 ` Long Cheng
2019-04-28 17:40 ` Sean Wang
1 sibling, 1 reply; 6+ messages in thread
From: Matthias Brugger @ 2019-04-25 10:40 UTC (permalink / raw)
To: Long Cheng, Greg Kroah-Hartman
Cc: Jiri Slaby, Gustavo A. R. Silva, Peter Shih, linux-serial,
linux-arm-kernel, linux-mediatek, linux-kernel, srv_heupstream,
Yingjoe Chen, YT Shen, Zhenbao Liu, Changqi Hu
On 25/04/2019 10:41, Long Cheng wrote:
> Add SW and HW follow control function.
Can you please explain a bit more what you are doing in this patch.
You change the setting of the registers for different baud rates. Please
elaborate what is happening there.
>
> Signed-off-by: Long Cheng <long.cheng@mediatek.com>
> ---
> drivers/tty/serial/8250/8250_mtk.c | 60 ++++++++++++++++++++++--------------
> 1 file changed, 37 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c
> index c1fdbc0..959fd85 100644
> --- a/drivers/tty/serial/8250/8250_mtk.c
> +++ b/drivers/tty/serial/8250/8250_mtk.c
> @@ -21,12 +21,14 @@
>
> #include "8250.h"
>
> -#define UART_MTK_HIGHS 0x09 /* Highspeed register */
> -#define UART_MTK_SAMPLE_COUNT 0x0a /* Sample count register */
> -#define UART_MTK_SAMPLE_POINT 0x0b /* Sample point register */
> +#define MTK_UART_HIGHS 0x09 /* Highspeed register */
> +#define MTK_UART_SAMPLE_COUNT 0x0a /* Sample count register */
> +#define MTK_UART_SAMPLE_POINT 0x0b /* Sample point register */
Rename looks good to me. But I'd prefer to have it in a separate patch.
> #define MTK_UART_RATE_FIX 0x0d /* UART Rate Fix Register */
> -
> #define MTK_UART_DMA_EN 0x13 /* DMA Enable register */
> +#define MTK_UART_RXTRI_AD 0x14 /* RX Trigger address */
> +#define MTK_UART_FRACDIV_L 0x15 /* Fractional divider LSB address */
> +#define MTK_UART_FRACDIV_M 0x16 /* Fractional divider MSB address */
> #define MTK_UART_DMA_EN_TX 0x2
> #define MTK_UART_DMA_EN_RX 0x5
>
> @@ -46,6 +48,7 @@ enum dma_rx_status {
> struct mtk8250_data {
> int line;
> unsigned int rx_pos;
> + unsigned int clk_count;
What is that for, not used in this patch.
> struct clk *uart_clk;
> struct clk *bus_clk;
> struct uart_8250_dma *dma;
> @@ -196,9 +199,15 @@ static void mtk8250_shutdown(struct uart_port *port)
> mtk8250_set_termios(struct uart_port *port, struct ktermios *termios,
> struct ktermios *old)
> {
> + unsigned short fraction_L_mapping[] = {
> + 0, 1, 0x5, 0x15, 0x55, 0x57, 0x57, 0x77, 0x7F, 0xFF, 0xFF
> + };
> + unsigned short fraction_M_mapping[] = {
> + 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 3
> + };
> struct uart_8250_port *up = up_to_u8250p(port);
> + unsigned int baud, quot, fraction;
> unsigned long flags;
> - unsigned int baud, quot;
>
> #ifdef CONFIG_SERIAL_8250_DMA
> if (up->dma) {
> @@ -214,7 +223,7 @@ static void mtk8250_shutdown(struct uart_port *port)
> serial8250_do_set_termios(port, termios, old);
>
> /*
> - * Mediatek UARTs use an extra highspeed register (UART_MTK_HIGHS)
> + * Mediatek UARTs use an extra highspeed register (MTK_UART_HIGHS)
> *
> * We need to recalcualte the quot register, as the claculation depends
> * on the vaule in the highspeed register.
> @@ -230,18 +239,11 @@ static void mtk8250_shutdown(struct uart_port *port)
> port->uartclk / 16 / UART_DIV_MAX,
> port->uartclk);
>
> - if (baud <= 115200) {
> - serial_port_out(port, UART_MTK_HIGHS, 0x0);
> + if (baud < 115200) {
> + serial_port_out(port, MTK_UART_HIGHS, 0x0);
> quot = uart_get_divisor(port, baud);
> - } else if (baud <= 576000) {
> - serial_port_out(port, UART_MTK_HIGHS, 0x2);
> -
> - /* Set to next lower baudrate supported */
> - if ((baud == 500000) || (baud == 576000))
> - baud = 460800;
> - quot = DIV_ROUND_UP(port->uartclk, 4 * baud);
So we allow now also these baud rates? Then you have to update the comment as well.
Regards,
Matthias
> } else {
> - serial_port_out(port, UART_MTK_HIGHS, 0x3);
> + serial_port_out(port, MTK_UART_HIGHS, 0x3);
> quot = DIV_ROUND_UP(port->uartclk, 256 * baud);
> }
>
> @@ -258,17 +260,29 @@ static void mtk8250_shutdown(struct uart_port *port)
> /* reset DLAB */
> serial_port_out(port, UART_LCR, up->lcr);
>
> - if (baud > 460800) {
> + if (baud >= 115200) {
> unsigned int tmp;
>
> - tmp = DIV_ROUND_CLOSEST(port->uartclk, quot * baud);
> - serial_port_out(port, UART_MTK_SAMPLE_COUNT, tmp - 1);
> - serial_port_out(port, UART_MTK_SAMPLE_POINT,
> - (tmp - 2) >> 1);
> + tmp = (port->uartclk / (baud * quot)) - 1;
> + serial_port_out(port, MTK_UART_SAMPLE_COUNT, tmp);
> + serial_port_out(port, MTK_UART_SAMPLE_POINT,
> + (tmp >> 1) - 1);
> +
> + /*count fraction to set fractoin register */
> + fraction = ((port->uartclk * 100) / baud / quot) % 100;
> + fraction = DIV_ROUND_CLOSEST(fraction, 10);
> + serial_port_out(port, MTK_UART_FRACDIV_L,
> + fraction_L_mapping[fraction]);
> + serial_port_out(port, MTK_UART_FRACDIV_M,
> + fraction_M_mapping[fraction]);
> } else {
> - serial_port_out(port, UART_MTK_SAMPLE_COUNT, 0x00);
> - serial_port_out(port, UART_MTK_SAMPLE_POINT, 0xff);
> + serial_port_out(port, MTK_UART_SAMPLE_COUNT, 0x00);
> + serial_port_out(port, MTK_UART_SAMPLE_POINT, 0xff);
> + serial_port_out(port, MTK_UART_FRACDIV_L, 0x00);
> + serial_port_out(port, MTK_UART_FRACDIV_M, 0x00);
> }
> + if (uart_console(port))
> + up->port.cons->cflag = termios->c_cflag;
>
> spin_unlock_irqrestore(&port->lock, flags);
> /* Don't rewrite B0 */
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 1/2] serial: 8250-mtk: add follow control
2019-04-25 10:40 ` Matthias Brugger
@ 2019-04-26 5:22 ` Long Cheng
0 siblings, 0 replies; 6+ messages in thread
From: Long Cheng @ 2019-04-26 5:22 UTC (permalink / raw)
To: Matthias Brugger
Cc: Greg Kroah-Hartman, Jiri Slaby, Gustavo A. R. Silva, Peter Shih,
linux-serial, linux-arm-kernel, linux-mediatek, linux-kernel,
srv_heupstream, Yingjoe Chen, YT Shen, Zhenbao Liu, Changqi Hu
On Thu, 2019-04-25 at 12:40 +0200, Matthias Brugger wrote:
>
> On 25/04/2019 10:41, Long Cheng wrote:
> > Add SW and HW follow control function.
>
> Can you please explain a bit more what you are doing in this patch.
> You change the setting of the registers for different baud rates. Please
> elaborate what is happening there.
>
Clock source is different. Sometimes, baudrate is greater than or equal
to 115200, we use highspeed of 3 algorithm and fractional divider to
ensure more accurate baudrate.
Next release version, I will update this to commit message
> >
> > Signed-off-by: Long Cheng <long.cheng@mediatek.com>
> > ---
> > drivers/tty/serial/8250/8250_mtk.c | 60 ++++++++++++++++++++++--------------
> > 1 file changed, 37 insertions(+), 23 deletions(-)
> >
> > diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c
> > index c1fdbc0..959fd85 100644
> > --- a/drivers/tty/serial/8250/8250_mtk.c
> > +++ b/drivers/tty/serial/8250/8250_mtk.c
> > @@ -21,12 +21,14 @@
> >
> > #include "8250.h"
> >
> > -#define UART_MTK_HIGHS 0x09 /* Highspeed register */
> > -#define UART_MTK_SAMPLE_COUNT 0x0a /* Sample count register */
> > -#define UART_MTK_SAMPLE_POINT 0x0b /* Sample point register */
> > +#define MTK_UART_HIGHS 0x09 /* Highspeed register */
> > +#define MTK_UART_SAMPLE_COUNT 0x0a /* Sample count register */
> > +#define MTK_UART_SAMPLE_POINT 0x0b /* Sample point register */
>
> Rename looks good to me. But I'd prefer to have it in a separate patch.
>
OK.
> > #define MTK_UART_RATE_FIX 0x0d /* UART Rate Fix Register */
> > -
> > #define MTK_UART_DMA_EN 0x13 /* DMA Enable register */
> > +#define MTK_UART_RXTRI_AD 0x14 /* RX Trigger address */
> > +#define MTK_UART_FRACDIV_L 0x15 /* Fractional divider LSB address */
> > +#define MTK_UART_FRACDIV_M 0x16 /* Fractional divider MSB address */
> > #define MTK_UART_DMA_EN_TX 0x2
> > #define MTK_UART_DMA_EN_RX 0x5
> >
> > @@ -46,6 +48,7 @@ enum dma_rx_status {
> > struct mtk8250_data {
> > int line;
> > unsigned int rx_pos;
> > + unsigned int clk_count;
>
> What is that for, not used in this patch.
>
It's for other patch. Sorry, I will remove it.
> > struct clk *uart_clk;
> > struct clk *bus_clk;
> > struct uart_8250_dma *dma;
> > @@ -196,9 +199,15 @@ static void mtk8250_shutdown(struct uart_port *port)
> > mtk8250_set_termios(struct uart_port *port, struct ktermios *termios,
> > struct ktermios *old)
> > {
> > + unsigned short fraction_L_mapping[] = {
> > + 0, 1, 0x5, 0x15, 0x55, 0x57, 0x57, 0x77, 0x7F, 0xFF, 0xFF
> > + };
> > + unsigned short fraction_M_mapping[] = {
> > + 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 3
> > + };
> > struct uart_8250_port *up = up_to_u8250p(port);
> > + unsigned int baud, quot, fraction;
> > unsigned long flags;
> > - unsigned int baud, quot;
> >
> > #ifdef CONFIG_SERIAL_8250_DMA
> > if (up->dma) {
> > @@ -214,7 +223,7 @@ static void mtk8250_shutdown(struct uart_port *port)
> > serial8250_do_set_termios(port, termios, old);
> >
> > /*
> > - * Mediatek UARTs use an extra highspeed register (UART_MTK_HIGHS)
> > + * Mediatek UARTs use an extra highspeed register (MTK_UART_HIGHS)
> > *
> > * We need to recalcualte the quot register, as the claculation depends
> > * on the vaule in the highspeed register.
> > @@ -230,18 +239,11 @@ static void mtk8250_shutdown(struct uart_port *port)
> > port->uartclk / 16 / UART_DIV_MAX,
> > port->uartclk);
> >
> > - if (baud <= 115200) {
> > - serial_port_out(port, UART_MTK_HIGHS, 0x0);
> > + if (baud < 115200) {
> > + serial_port_out(port, MTK_UART_HIGHS, 0x0);
> > quot = uart_get_divisor(port, baud);
> > - } else if (baud <= 576000) {
> > - serial_port_out(port, UART_MTK_HIGHS, 0x2);
> > -
> > - /* Set to next lower baudrate supported */
> > - if ((baud == 500000) || (baud == 576000))
> > - baud = 460800;
> > - quot = DIV_ROUND_UP(port->uartclk, 4 * baud);
>
> So we allow now also these baud rates? Then you have to update the comment as well.
>
Yes.
When clock source is different, data sometimes is error by the previous
algorithm. It's not good. So we update new method to fix the issue.
> Regards,
> Matthias
>
> > } else {
> > - serial_port_out(port, UART_MTK_HIGHS, 0x3);
> > + serial_port_out(port, MTK_UART_HIGHS, 0x3);
> > quot = DIV_ROUND_UP(port->uartclk, 256 * baud);
> > }
> >
> > @@ -258,17 +260,29 @@ static void mtk8250_shutdown(struct uart_port *port)
> > /* reset DLAB */
> > serial_port_out(port, UART_LCR, up->lcr);
> >
> > - if (baud > 460800) {
> > + if (baud >= 115200) {
> > unsigned int tmp;
> >
> > - tmp = DIV_ROUND_CLOSEST(port->uartclk, quot * baud);
> > - serial_port_out(port, UART_MTK_SAMPLE_COUNT, tmp - 1);
> > - serial_port_out(port, UART_MTK_SAMPLE_POINT,
> > - (tmp - 2) >> 1);
> > + tmp = (port->uartclk / (baud * quot)) - 1;
> > + serial_port_out(port, MTK_UART_SAMPLE_COUNT, tmp);
> > + serial_port_out(port, MTK_UART_SAMPLE_POINT,
> > + (tmp >> 1) - 1);
> > +
> > + /*count fraction to set fractoin register */
> > + fraction = ((port->uartclk * 100) / baud / quot) % 100;
> > + fraction = DIV_ROUND_CLOSEST(fraction, 10);
> > + serial_port_out(port, MTK_UART_FRACDIV_L,
> > + fraction_L_mapping[fraction]);
> > + serial_port_out(port, MTK_UART_FRACDIV_M,
> > + fraction_M_mapping[fraction]);
> > } else {
> > - serial_port_out(port, UART_MTK_SAMPLE_COUNT, 0x00);
> > - serial_port_out(port, UART_MTK_SAMPLE_POINT, 0xff);
> > + serial_port_out(port, MTK_UART_SAMPLE_COUNT, 0x00);
> > + serial_port_out(port, MTK_UART_SAMPLE_POINT, 0xff);
> > + serial_port_out(port, MTK_UART_FRACDIV_L, 0x00);
> > + serial_port_out(port, MTK_UART_FRACDIV_M, 0x00);
> > }
> > + if (uart_console(port))
> > + up->port.cons->cflag = termios->c_cflag;
> >
> > spin_unlock_irqrestore(&port->lock, flags);
> > /* Don't rewrite B0 */
> >
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 1/2] serial: 8250-mtk: add follow control
2019-04-25 8:41 ` [PATCH 1/2] serial: 8250-mtk: add follow control Long Cheng
2019-04-25 10:40 ` Matthias Brugger
@ 2019-04-28 17:40 ` Sean Wang
1 sibling, 0 replies; 6+ messages in thread
From: Sean Wang @ 2019-04-28 17:40 UTC (permalink / raw)
To: Long Cheng
Cc: Greg Kroah-Hartman, Zhenbao Liu, Peter Shih, srv_heupstream,
Gustavo A. R. Silva, Changqi Hu, linux-kernel, linux-mediatek,
linux-serial, Jiri Slaby, Matthias Brugger, Yingjoe Chen,
linux-arm-kernel
Hi, Long
I guess you should mean "flow control", not "follow control".
And the commit subject should be swapped between 1/2 and 2/2,
otherwise, the subject is inconsistent with its own content.
Sean
On Thu, Apr 25, 2019 at 1:41 AM Long Cheng <long.cheng@mediatek.com> wrote:
>
> Add SW and HW follow control function.
>
> Signed-off-by: Long Cheng <long.cheng@mediatek.com>
> ---
> drivers/tty/serial/8250/8250_mtk.c | 60 ++++++++++++++++++++++--------------
> 1 file changed, 37 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c
> index c1fdbc0..959fd85 100644
> --- a/drivers/tty/serial/8250/8250_mtk.c
> +++ b/drivers/tty/serial/8250/8250_mtk.c
> @@ -21,12 +21,14 @@
>
> #include "8250.h"
>
> -#define UART_MTK_HIGHS 0x09 /* Highspeed register */
> -#define UART_MTK_SAMPLE_COUNT 0x0a /* Sample count register */
> -#define UART_MTK_SAMPLE_POINT 0x0b /* Sample point register */
> +#define MTK_UART_HIGHS 0x09 /* Highspeed register */
> +#define MTK_UART_SAMPLE_COUNT 0x0a /* Sample count register */
> +#define MTK_UART_SAMPLE_POINT 0x0b /* Sample point register */
> #define MTK_UART_RATE_FIX 0x0d /* UART Rate Fix Register */
> -
> #define MTK_UART_DMA_EN 0x13 /* DMA Enable register */
> +#define MTK_UART_RXTRI_AD 0x14 /* RX Trigger address */
> +#define MTK_UART_FRACDIV_L 0x15 /* Fractional divider LSB address */
> +#define MTK_UART_FRACDIV_M 0x16 /* Fractional divider MSB address */
> #define MTK_UART_DMA_EN_TX 0x2
> #define MTK_UART_DMA_EN_RX 0x5
>
> @@ -46,6 +48,7 @@ enum dma_rx_status {
> struct mtk8250_data {
> int line;
> unsigned int rx_pos;
> + unsigned int clk_count;
> struct clk *uart_clk;
> struct clk *bus_clk;
> struct uart_8250_dma *dma;
> @@ -196,9 +199,15 @@ static void mtk8250_shutdown(struct uart_port *port)
> mtk8250_set_termios(struct uart_port *port, struct ktermios *termios,
> struct ktermios *old)
> {
> + unsigned short fraction_L_mapping[] = {
> + 0, 1, 0x5, 0x15, 0x55, 0x57, 0x57, 0x77, 0x7F, 0xFF, 0xFF
> + };
> + unsigned short fraction_M_mapping[] = {
> + 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 3
> + };
> struct uart_8250_port *up = up_to_u8250p(port);
> + unsigned int baud, quot, fraction;
> unsigned long flags;
> - unsigned int baud, quot;
>
> #ifdef CONFIG_SERIAL_8250_DMA
> if (up->dma) {
> @@ -214,7 +223,7 @@ static void mtk8250_shutdown(struct uart_port *port)
> serial8250_do_set_termios(port, termios, old);
>
> /*
> - * Mediatek UARTs use an extra highspeed register (UART_MTK_HIGHS)
> + * Mediatek UARTs use an extra highspeed register (MTK_UART_HIGHS)
> *
> * We need to recalcualte the quot register, as the claculation depends
> * on the vaule in the highspeed register.
> @@ -230,18 +239,11 @@ static void mtk8250_shutdown(struct uart_port *port)
> port->uartclk / 16 / UART_DIV_MAX,
> port->uartclk);
>
> - if (baud <= 115200) {
> - serial_port_out(port, UART_MTK_HIGHS, 0x0);
> + if (baud < 115200) {
> + serial_port_out(port, MTK_UART_HIGHS, 0x0);
> quot = uart_get_divisor(port, baud);
> - } else if (baud <= 576000) {
> - serial_port_out(port, UART_MTK_HIGHS, 0x2);
> -
> - /* Set to next lower baudrate supported */
> - if ((baud == 500000) || (baud == 576000))
> - baud = 460800;
> - quot = DIV_ROUND_UP(port->uartclk, 4 * baud);
> } else {
> - serial_port_out(port, UART_MTK_HIGHS, 0x3);
> + serial_port_out(port, MTK_UART_HIGHS, 0x3);
> quot = DIV_ROUND_UP(port->uartclk, 256 * baud);
> }
>
> @@ -258,17 +260,29 @@ static void mtk8250_shutdown(struct uart_port *port)
> /* reset DLAB */
> serial_port_out(port, UART_LCR, up->lcr);
>
> - if (baud > 460800) {
> + if (baud >= 115200) {
> unsigned int tmp;
>
> - tmp = DIV_ROUND_CLOSEST(port->uartclk, quot * baud);
> - serial_port_out(port, UART_MTK_SAMPLE_COUNT, tmp - 1);
> - serial_port_out(port, UART_MTK_SAMPLE_POINT,
> - (tmp - 2) >> 1);
> + tmp = (port->uartclk / (baud * quot)) - 1;
> + serial_port_out(port, MTK_UART_SAMPLE_COUNT, tmp);
> + serial_port_out(port, MTK_UART_SAMPLE_POINT,
> + (tmp >> 1) - 1);
> +
> + /*count fraction to set fractoin register */
> + fraction = ((port->uartclk * 100) / baud / quot) % 100;
> + fraction = DIV_ROUND_CLOSEST(fraction, 10);
> + serial_port_out(port, MTK_UART_FRACDIV_L,
> + fraction_L_mapping[fraction]);
> + serial_port_out(port, MTK_UART_FRACDIV_M,
> + fraction_M_mapping[fraction]);
> } else {
> - serial_port_out(port, UART_MTK_SAMPLE_COUNT, 0x00);
> - serial_port_out(port, UART_MTK_SAMPLE_POINT, 0xff);
> + serial_port_out(port, MTK_UART_SAMPLE_COUNT, 0x00);
> + serial_port_out(port, MTK_UART_SAMPLE_POINT, 0xff);
> + serial_port_out(port, MTK_UART_FRACDIV_L, 0x00);
> + serial_port_out(port, MTK_UART_FRACDIV_M, 0x00);
> }
> + if (uart_console(port))
> + up->port.cons->cflag = termios->c_cflag;
>
> spin_unlock_irqrestore(&port->lock, flags);
> /* Don't rewrite B0 */
> --
> 1.7.9.5
>
>
> _______________________________________________
> Linux-mediatek mailing list
> Linux-mediatek@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-mediatek
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2019-04-28 17:41 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-04-25 8:41 [PATCH 0/2] Perfect 8250 mtk uart function Long Cheng
2019-04-25 8:41 ` [PATCH 1/2] serial: 8250-mtk: add follow control Long Cheng
2019-04-25 10:40 ` Matthias Brugger
2019-04-26 5:22 ` Long Cheng
2019-04-28 17:40 ` Sean Wang
2019-04-25 8:41 ` [PATCH 2/2] serial: 8250-mtk: modify baudrate setting Long Cheng
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