[PATCH v4 2/2] serial: qcom-geni: Add tracepoints for Qualcomm GENI serial driver

[Praveen Talari]

Add tracing to the Qualcomm GENI serial driver to improve runtime
observability.

Trace hooks are added at key points including termios and clock
configuration, manual control get/set, interrupt handling, and data
TX/RX paths.

Reviewed-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxxxx>
Signed-off-by: Praveen Talari <praveen.talari@xxxxxxxxxxxxxxxx>
---
v2->v3:
- Updated commit text(removed example as it was available on cover
  letter).
---
 drivers/tty/serial/qcom_geni_serial.c | 27 +++++++++++++++++++++++----
 1 file changed, 23 insertions(+), 4 deletions(-)

diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c
index d81b539cff7f..4b62e58d4918 100644
--- a/drivers/tty/serial/qcom_geni_serial.c
+++ b/drivers/tty/serial/qcom_geni_serial.c
@@ -7,6 +7,9 @@
 /* Disable MMIO tracing to prevent excessive logging of unwanted MMIO traces */
 #define __DISABLE_TRACE_MMIO__
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/qcom_geni_serial.h>
+
 #include <linux/clk.h>
 #include <linux/console.h>
 #include <linux/io.h>
@@ -226,7 +229,7 @@ static void qcom_geni_serial_config_port(struct uart_port *uport, int cfg_flags)
 static unsigned int qcom_geni_serial_get_mctrl(struct uart_port *uport)
 {
 	unsigned int mctrl = TIOCM_DSR | TIOCM_CAR;
-	u32 geni_ios;
+	u32 geni_ios = 0;
 
 	if (uart_console(uport)) {
 		mctrl |= TIOCM_CTS;
@@ -236,6 +239,8 @@ static unsigned int qcom_geni_serial_get_mctrl(struct uart_port *uport)
 			mctrl |= TIOCM_CTS;
 	}
 
+	trace_geni_serial_get_mctrl(uport->dev, mctrl, geni_ios);
+
 	return mctrl;
 }
 
@@ -254,6 +259,8 @@ static void qcom_geni_serial_set_mctrl(struct uart_port *uport,
 	if (port->manual_flow && !(mctrl & TIOCM_RTS) && !uport->suspended)
 		uart_manual_rfr = UART_MANUAL_RFR_EN | UART_RFR_NOT_READY;
 	writel(uart_manual_rfr, uport->membase + SE_UART_MANUAL_RFR);
+
+	trace_geni_serial_set_mctrl(uport->dev, mctrl, uart_manual_rfr);
 }
 
 static const char *qcom_geni_serial_get_type(struct uart_port *uport)
@@ -684,6 +691,8 @@ static void qcom_geni_serial_start_tx_dma(struct uart_port *uport)
 	xmit_size = kfifo_out_linear_ptr(&tport->xmit_fifo, &tail,
 			UART_XMIT_SIZE);
 
+	trace_geni_serial_tx_data(uport->dev, tail, xmit_size);
+
 	qcom_geni_set_rs485_mode(uport, SER_RS485_RTS_ON_SEND);
 
 	qcom_geni_serial_setup_tx(uport, xmit_size);
@@ -910,8 +919,10 @@ static void qcom_geni_serial_handle_rx_dma(struct uart_port *uport, bool drop)
 		return;
 	}
 
-	if (!drop)
+	if (!drop) {
+		trace_geni_serial_rx_data(uport->dev, port->rx_buf, rx_in);
 		handle_rx_uart(uport, rx_in);
+	}
 
 	ret = geni_se_rx_dma_prep(&port->se, port->rx_buf,
 				  DMA_RX_BUF_SIZE,
@@ -1082,6 +1093,10 @@ static irqreturn_t qcom_geni_serial_isr(int isr, void *dev)
 	geni_status = readl(uport->membase + SE_GENI_STATUS);
 	dma = readl(uport->membase + SE_GENI_DMA_MODE_EN);
 	m_irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN);
+
+	trace_geni_serial_irq(uport->dev, m_irq_status, s_irq_status,
+			      dma_tx_status, dma_rx_status);
+
 	writel(m_irq_status, uport->membase + SE_GENI_M_IRQ_CLEAR);
 	writel(s_irq_status, uport->membase + SE_GENI_S_IRQ_CLEAR);
 	writel(dma_tx_status, uport->membase + SE_DMA_TX_IRQ_CLR);
@@ -1294,8 +1309,8 @@ static int geni_serial_set_rate(struct uart_port *uport, unsigned int baud)
 		return -EINVAL;
 	}
 
-	dev_dbg(port->se.dev, "desired_rate = %u, clk_rate = %lu, clk_div = %u, clk_idx = %u\n",
-		baud * sampling_rate, clk_rate, clk_div, clk_idx);
+	trace_geni_serial_clk_cfg(uport->dev, baud * sampling_rate, clk_rate,
+				  clk_div, clk_idx);
 
 	uport->uartclk = clk_rate;
 	port->clk_rate = clk_rate;
@@ -1455,6 +1470,10 @@ static void qcom_geni_serial_set_termios(struct uart_port *uport,
 	writel(bits_per_char, uport->membase + SE_UART_TX_WORD_LEN);
 	writel(bits_per_char, uport->membase + SE_UART_RX_WORD_LEN);
 	writel(stop_bit_len, uport->membase + SE_UART_TX_STOP_BIT_LEN);
+
+	trace_geni_serial_set_termios(uport->dev, baud, bits_per_char,
+				      tx_trans_cfg, tx_parity_cfg, rx_trans_cfg,
+				      rx_parity_cfg, stop_bit_len);
 }
 
 #ifdef CONFIG_SERIAL_QCOM_GENI_CONSOLE

-- 
2.34.1