+++ /dev/null
---- a/drivers/tty/serial/ar933x_uart.c
-+++ b/drivers/tty/serial/ar933x_uart.c
-@@ -25,11 +25,19 @@
- #include <linux/io.h>
- #include <linux/irq.h>
-
-+#include <asm/div64.h>
-+
- #include <asm/mach-ath79/ar933x_uart.h>
- #include <asm/mach-ath79/ar933x_uart_platform.h>
-
- #define DRIVER_NAME "ar933x-uart"
-
-+#define AR933X_UART_MAX_SCALE 0xff
-+#define AR933X_UART_MAX_STEP 0xffff
-+
-+#define AR933X_UART_MIN_BAUD 300
-+#define AR933X_UART_MAX_BAUD 3000000
-+
- #define AR933X_DUMMY_STATUS_RD 0x01
-
- static struct uart_driver ar933x_uart_driver;
-@@ -37,6 +45,8 @@ static struct uart_driver ar933x_uart_dr
- struct ar933x_uart_port {
- struct uart_port port;
- unsigned int ier; /* shadow Interrupt Enable Register */
-+ unsigned int min_baud;
-+ unsigned int max_baud;
- };
-
- static inline unsigned int ar933x_uart_read(struct ar933x_uart_port *up,
-@@ -162,6 +172,57 @@ static void ar933x_uart_enable_ms(struct
- {
- }
-
-+/*
-+ * baudrate = (clk / (scale + 1)) * (step * (1 / 2^17))
-+ */
-+static unsigned long ar933x_uart_get_baud(unsigned int clk,
-+ unsigned int scale,
-+ unsigned int step)
-+{
-+ u64 t;
-+ u32 div;
-+
-+ div = (2 << 16) * (scale + 1);
-+ t = clk;
-+ t *= step;
-+ t += (div / 2);
-+ do_div(t, div);
-+
-+ return t;
-+}
-+
-+static void ar933x_uart_get_scale_step(unsigned int clk,
-+ unsigned int baud,
-+ unsigned int *scale,
-+ unsigned int *step)
-+{
-+ unsigned int tscale;
-+ long min_diff;
-+
-+ *scale = 0;
-+ *step = 0;
-+
-+ min_diff = baud;
-+ for (tscale = 0; tscale < AR933X_UART_MAX_SCALE; tscale++) {
-+ u64 tstep;
-+ int diff;
-+
-+ tstep = baud * (tscale + 1);
-+ tstep *= (2 << 16);
-+ do_div(tstep, clk);
-+
-+ if (tstep > AR933X_UART_MAX_STEP)
-+ break;
-+
-+ diff = abs(ar933x_uart_get_baud(clk, tscale, tstep) - baud);
-+ if (diff < min_diff) {
-+ min_diff = diff;
-+ *scale = tscale;
-+ *step = tstep;
-+ }
-+ }
-+}
-+
- static void ar933x_uart_set_termios(struct uart_port *port,
- struct ktermios *new,
- struct ktermios *old)
-@@ -169,7 +230,7 @@ static void ar933x_uart_set_termios(stru
- struct ar933x_uart_port *up = (struct ar933x_uart_port *) port;
- unsigned int cs;
- unsigned long flags;
-- unsigned int baud, scale;
-+ unsigned int baud, scale, step;
-
- /* Only CS8 is supported */
- new->c_cflag &= ~CSIZE;
-@@ -191,8 +252,8 @@ static void ar933x_uart_set_termios(stru
- /* Mark/space parity is not supported */
- new->c_cflag &= ~CMSPAR;
-
-- baud = uart_get_baud_rate(port, new, old, 0, port->uartclk / 16);
-- scale = (port->uartclk / (16 * baud)) - 1;
-+ baud = uart_get_baud_rate(port, new, old, up->min_baud, up->max_baud);
-+ ar933x_uart_get_scale_step(port->uartclk, baud, &scale, &step);
-
- /*
- * Ok, we're now changing the port state. Do it with
-@@ -200,6 +261,10 @@ static void ar933x_uart_set_termios(stru
- */
- spin_lock_irqsave(&up->port.lock, flags);
-
-+ /* disable the UART */
-+ ar933x_uart_rmw_clear(up, AR933X_UART_CS_REG,
-+ AR933X_UART_CS_IF_MODE_M << AR933X_UART_CS_IF_MODE_S);
-+
- /* Update the per-port timeout. */
- uart_update_timeout(port, new->c_cflag, baud);
-
-@@ -210,7 +275,7 @@ static void ar933x_uart_set_termios(stru
- up->port.ignore_status_mask |= AR933X_DUMMY_STATUS_RD;
-
- ar933x_uart_write(up, AR933X_UART_CLOCK_REG,
-- scale << AR933X_UART_CLOCK_SCALE_S | 8192);
-+ scale << AR933X_UART_CLOCK_SCALE_S | step);
-
- /* setup configuration register */
- ar933x_uart_rmw(up, AR933X_UART_CS_REG, AR933X_UART_CS_PARITY_M, cs);
-@@ -219,6 +284,11 @@ static void ar933x_uart_set_termios(stru
- ar933x_uart_rmw_set(up, AR933X_UART_CS_REG,
- AR933X_UART_CS_HOST_INT_EN);
-
-+ /* reenable the UART */
-+ ar933x_uart_rmw(up, AR933X_UART_CS_REG,
-+ AR933X_UART_CS_IF_MODE_M << AR933X_UART_CS_IF_MODE_S,
-+ AR933X_UART_CS_IF_MODE_DCE << AR933X_UART_CS_IF_MODE_S);
-+
- spin_unlock_irqrestore(&up->port.lock, flags);
-
- if (tty_termios_baud_rate(new))
-@@ -401,6 +471,8 @@ static void ar933x_uart_config_port(stru
- static int ar933x_uart_verify_port(struct uart_port *port,
- struct serial_struct *ser)
- {
-+ struct ar933x_uart_port *up = (struct ar933x_uart_port *) port;
-+
- if (ser->type != PORT_UNKNOWN &&
- ser->type != PORT_AR933X)
- return -EINVAL;
-@@ -408,7 +480,8 @@ static int ar933x_uart_verify_port(struc
- if (ser->irq < 0 || ser->irq >= NR_IRQS)
- return -EINVAL;
-
-- if (ser->baud_base < 28800)
-+ if (ser->baud_base < up->min_baud ||
-+ ser->baud_base > up->max_baud)
- return -EINVAL;
-
- return 0;
-@@ -561,6 +634,7 @@ static int __devinit ar933x_uart_probe(s
- struct uart_port *port;
- struct resource *mem_res;
- struct resource *irq_res;
-+ unsigned int baud;
- int id;
- int ret;
-
-@@ -611,6 +685,12 @@ static int __devinit ar933x_uart_probe(s
- port->fifosize = AR933X_UART_FIFO_SIZE;
- port->ops = &ar933x_uart_ops;
-
-+ baud = ar933x_uart_get_baud(port->uartclk, AR933X_UART_MAX_SCALE, 1);
-+ up->min_baud = max_t(unsigned int, baud, AR933X_UART_MIN_BAUD);
-+
-+ baud = ar933x_uart_get_baud(port->uartclk, 0, AR933X_UART_MAX_STEP);
-+ up->max_baud = min_t(unsigned int, baud, AR933X_UART_MAX_BAUD);
-+
- ar933x_uart_add_console_port(up);
-
- ret = uart_add_one_port(&ar933x_uart_driver, &up->port);
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