[PATCH v6 2/2] serial: qcom-geni: Add tracepoints for Qualcomm GENI serial driver

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 <[email protected]>
Signed-off-by: Praveen Talari <[email protected]>
---
 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 7ead87b4eb65..23024fef95bb 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);
@@ -907,8 +916,10 @@ static void qcom_geni_serial_handle_rx_dma(struct uart_port *uport, bool drop)
 	rx_in = readl(uport->membase + SE_DMA_RX_LEN_IN);
 	if (!rx_in)
 		dev_warn_ratelimited(uport->dev, "serial engine reports 0 RX bytes in!\n");
-	else if (!drop)
+	else 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,
@@ -1079,6 +1090,10 @@ 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);
@@ -1291,8 +1306,8 @@ 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;
@@ -1452,6 +1467,10 @@ 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