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-rw-r--r--drivers/tty/serial/8250/8250_bcm7271.c101
-rw-r--r--drivers/tty/serial/8250/8250_mtk.c8
-rw-r--r--drivers/tty/serial/sc16is7xx.c23
3 files changed, 84 insertions, 48 deletions
diff --git a/drivers/tty/serial/8250/8250_bcm7271.c b/drivers/tty/serial/8250/8250_bcm7271.c
index 504c4c0208..4f8b70f8ce 100644
--- a/drivers/tty/serial/8250/8250_bcm7271.c
+++ b/drivers/tty/serial/8250/8250_bcm7271.c
@@ -676,18 +676,46 @@ static void init_real_clk_rates(struct device *dev, struct brcmuart_priv *priv)
clk_set_rate(priv->baud_mux_clk, priv->default_mux_rate);
}
+static u32 find_quot(struct device *dev, u32 freq, u32 baud, u32 *percent)
+{
+ u32 quot;
+ u32 rate;
+ u64 hires_rate;
+ u64 hires_baud;
+ u64 hires_err;
+
+ rate = freq / 16;
+ quot = DIV_ROUND_CLOSEST(rate, baud);
+ if (!quot)
+ return 0;
+
+ /* increase resolution to get xx.xx percent */
+ hires_rate = div_u64((u64)rate * 10000, (u64)quot);
+ hires_baud = (u64)baud * 10000;
+
+ /* get the delta */
+ if (hires_rate > hires_baud)
+ hires_err = (hires_rate - hires_baud);
+ else
+ hires_err = (hires_baud - hires_rate);
+
+ *percent = (unsigned long)DIV_ROUND_CLOSEST_ULL(hires_err, baud);
+
+ dev_dbg(dev, "Baud rate: %u, MUX Clk: %u, Error: %u.%u%%\n",
+ baud, freq, *percent / 100, *percent % 100);
+
+ return quot;
+}
+
static void set_clock_mux(struct uart_port *up, struct brcmuart_priv *priv,
u32 baud)
{
u32 percent;
u32 best_percent = UINT_MAX;
u32 quot;
+ u32 freq;
u32 best_quot = 1;
- u32 rate;
- int best_index = -1;
- u64 hires_rate;
- u64 hires_baud;
- u64 hires_err;
+ u32 best_freq = 0;
int rc;
int i;
int real_baud;
@@ -696,44 +724,35 @@ static void set_clock_mux(struct uart_port *up, struct brcmuart_priv *priv,
if (priv->baud_mux_clk == NULL)
return;
- /* Find the closest match for specified baud */
- for (i = 0; i < ARRAY_SIZE(priv->real_rates); i++) {
- if (priv->real_rates[i] == 0)
- continue;
- rate = priv->real_rates[i] / 16;
- quot = DIV_ROUND_CLOSEST(rate, baud);
- if (!quot)
- continue;
-
- /* increase resolution to get xx.xx percent */
- hires_rate = (u64)rate * 10000;
- hires_baud = (u64)baud * 10000;
-
- hires_err = div_u64(hires_rate, (u64)quot);
-
- /* get the delta */
- if (hires_err > hires_baud)
- hires_err = (hires_err - hires_baud);
- else
- hires_err = (hires_baud - hires_err);
-
- percent = (unsigned long)DIV_ROUND_CLOSEST_ULL(hires_err, baud);
- dev_dbg(up->dev,
- "Baud rate: %u, MUX Clk: %u, Error: %u.%u%%\n",
- baud, priv->real_rates[i], percent / 100,
- percent % 100);
- if (percent < best_percent) {
- best_percent = percent;
- best_index = i;
- best_quot = quot;
+ /* Try default_mux_rate first */
+ quot = find_quot(up->dev, priv->default_mux_rate, baud, &percent);
+ if (quot) {
+ best_percent = percent;
+ best_freq = priv->default_mux_rate;
+ best_quot = quot;
+ }
+ /* If more than 1% error, find the closest match for specified baud */
+ if (best_percent > 100) {
+ for (i = 0; i < ARRAY_SIZE(priv->real_rates); i++) {
+ freq = priv->real_rates[i];
+ if (freq == 0 || freq == priv->default_mux_rate)
+ continue;
+ quot = find_quot(up->dev, freq, baud, &percent);
+ if (!quot)
+ continue;
+
+ if (percent < best_percent) {
+ best_percent = percent;
+ best_freq = freq;
+ best_quot = quot;
+ }
}
}
- if (best_index == -1) {
+ if (!best_freq) {
dev_err(up->dev, "Error, %d BAUD rate is too fast.\n", baud);
return;
}
- rate = priv->real_rates[best_index];
- rc = clk_set_rate(priv->baud_mux_clk, rate);
+ rc = clk_set_rate(priv->baud_mux_clk, best_freq);
if (rc)
dev_err(up->dev, "Error selecting BAUD MUX clock\n");
@@ -742,8 +761,8 @@ static void set_clock_mux(struct uart_port *up, struct brcmuart_priv *priv,
dev_err(up->dev, "Error, baud: %d has %u.%u%% error\n",
baud, percent / 100, percent % 100);
- real_baud = rate / 16 / best_quot;
- dev_dbg(up->dev, "Selecting BAUD MUX rate: %u\n", rate);
+ real_baud = best_freq / 16 / best_quot;
+ dev_dbg(up->dev, "Selecting BAUD MUX rate: %u\n", best_freq);
dev_dbg(up->dev, "Requested baud: %u, Actual baud: %u\n",
baud, real_baud);
@@ -752,7 +771,7 @@ static void set_clock_mux(struct uart_port *up, struct brcmuart_priv *priv,
i += (i / 2);
priv->char_wait = ns_to_ktime(i);
- up->uartclk = rate;
+ up->uartclk = best_freq;
}
static void brcmstb_set_termios(struct uart_port *up,
diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c
index 9ff6bbe9c0..d14988d149 100644
--- a/drivers/tty/serial/8250/8250_mtk.c
+++ b/drivers/tty/serial/8250/8250_mtk.c
@@ -209,15 +209,19 @@ static int mtk8250_startup(struct uart_port *port)
static void mtk8250_shutdown(struct uart_port *port)
{
-#ifdef CONFIG_SERIAL_8250_DMA
struct uart_8250_port *up = up_to_u8250p(port);
struct mtk8250_data *data = port->private_data;
+ int irq = data->rx_wakeup_irq;
+#ifdef CONFIG_SERIAL_8250_DMA
if (up->dma)
data->rx_status = DMA_RX_SHUTDOWN;
#endif
- return serial8250_do_shutdown(port);
+ serial8250_do_shutdown(port);
+
+ if (irq >= 0)
+ serial8250_do_set_mctrl(&up->port, TIOCM_RTS);
}
static void mtk8250_disable_intrs(struct uart_8250_port *up, int mask)
diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
index 929206a9a6..12915fffac 100644
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -554,16 +554,28 @@ static bool sc16is7xx_regmap_noinc(struct device *dev, unsigned int reg)
return reg == SC16IS7XX_RHR_REG;
}
+/*
+ * Configure programmable baud rate generator (divisor) according to the
+ * desired baud rate.
+ *
+ * From the datasheet, the divisor is computed according to:
+ *
+ * XTAL1 input frequency
+ * -----------------------
+ * prescaler
+ * divisor = ---------------------------
+ * baud-rate x sampling-rate
+ */
static int sc16is7xx_set_baud(struct uart_port *port, int baud)
{
struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
u8 lcr;
- u8 prescaler = 0;
+ unsigned int prescaler = 1;
unsigned long clk = port->uartclk, div = clk / 16 / baud;
if (div >= BIT(16)) {
- prescaler = SC16IS7XX_MCR_CLKSEL_BIT;
- div /= 4;
+ prescaler = 4;
+ div /= prescaler;
}
/* Enable enhanced features */
@@ -573,9 +585,10 @@ static int sc16is7xx_set_baud(struct uart_port *port, int baud)
SC16IS7XX_EFR_ENABLE_BIT);
sc16is7xx_efr_unlock(port);
+ /* If bit MCR_CLKSEL is set, the divide by 4 prescaler is activated. */
sc16is7xx_port_update(port, SC16IS7XX_MCR_REG,
SC16IS7XX_MCR_CLKSEL_BIT,
- prescaler);
+ prescaler == 1 ? 0 : SC16IS7XX_MCR_CLKSEL_BIT);
/* Backup LCR and access special register set (DLL/DLH) */
lcr = sc16is7xx_port_read(port, SC16IS7XX_LCR_REG);
@@ -591,7 +604,7 @@ static int sc16is7xx_set_baud(struct uart_port *port, int baud)
/* Restore LCR and access to general register set */
sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr);
- return DIV_ROUND_CLOSEST(clk / 16, div);
+ return DIV_ROUND_CLOSEST((clk / prescaler) / 16, div);
}
static void sc16is7xx_handle_rx(struct uart_port *port, unsigned int rxlen,
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-02 10:59:43 +0000