Re: [PATCH v7 11/12] tty: serial: Add Nuvoton ma35d1 serial driver support

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On 12. 04. 23, 7:38, Jacky Huang wrote:
From: Jacky Huang <ychuang3@xxxxxxxxxxx>

This adds UART and console driver for Nuvoton ma35d1 Soc.
It supports full-duplex communication, FIFO control, and
hardware flow control.

Signed-off-by: Jacky Huang <ychuang3@xxxxxxxxxxx>
...
--- /dev/null
+++ b/drivers/tty/serial/ma35d1_serial.c
@@ -0,0 +1,773 @@
...
+static void transmit_chars(struct uart_ma35d1_port *up)
+{
+	int count;

count is unsigned.

+	u8 ch;
+
+	if (uart_tx_stopped(&up->port)) {
+		ma35d1serial_stop_tx(&up->port);
+		return;
+	}
+	count = UART_FIFO_DEPTH - ((serial_in(up, UART_REG_FSR) & FSR_TXPTR_MSK) >> 16);

So this could be FIELD_GET() while you are defining FSR_TXPTR_MSK using GENMASK(), right?

+	uart_port_tx_limited(&up->port, ch, count,
+			     !(serial_in(up, UART_REG_FSR) & FSR_TX_FULL),
+			     serial_out(up, UART_REG_THR, ch),
+			     ({}));
+}
...
+static void ma35d1serial_set_termios(struct uart_port *port,
+				     struct ktermios *termios,
+				     const struct ktermios *old)
+{
+	struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+	u32 lcr = 0;
+	unsigned long flags;
+	u32 baud, quot;
+
+	lcr = UART_LCR_WLEN(tty_get_char_size(termios->c_cflag));
+
+	if (termios->c_cflag & CSTOPB)
+		lcr |= LCR_NSB;
+	if (termios->c_cflag & PARENB)
+		lcr |= LCR_PBE;
+	if (!(termios->c_cflag & PARODD))
+		lcr |= LCR_EPE;
+	if (termios->c_cflag & CMSPAR)
+		lcr |= LCR_SPE;
+
+	baud = uart_get_baud_rate(port, termios, old, port->uartclk / 0xffff,
+				  port->uartclk / 11);
+
+	quot = ma35d1serial_get_divisor(port, baud);
+
+	/*
+	 * Ok, we're now changing the port state.  Do it with
+	 * interrupts disabled.
+	 */
+	spin_lock_irqsave(&up->port.lock, flags);
+
+	up->port.read_status_mask = FSR_RX_OVER_IF;
+	if (termios->c_iflag & INPCK)
+		up->port.read_status_mask |= FSR_FEF | FSR_PEF;
+	if (termios->c_iflag & (BRKINT | PARMRK))
+		up->port.read_status_mask |= FSR_BIF;
+
+	/*
+	 * Characteres to ignore

"Characters"

The comment could be oneline.

+	 */
+	up->port.ignore_status_mask = 0;
+	if (termios->c_iflag & IGNPAR)
+		up->port.ignore_status_mask |= FSR_FEF | FSR_PEF;
+	if (termios->c_iflag & IGNBRK) {
+		up->port.ignore_status_mask |= FSR_BIF;
+		/*
+		 * If we're ignoring parity and break indicators,
+		 * ignore overruns too (for real raw support).
+		 */
+		if (termios->c_iflag & IGNPAR)
+			up->port.ignore_status_mask |= FSR_RX_OVER_IF;
+	}

Actually I don't understand the "Characteres" comment above at all. What characters?

+	if (termios->c_cflag & CRTSCTS)
+		up->mcr |= UART_MCR_AFE;
+	else
+		up->mcr &= ~UART_MCR_AFE;
+
+	uart_update_timeout(port, termios->c_cflag, baud);
+	ma35d1serial_set_mctrl(&up->port, up->port.mctrl);
+	serial_out(up, UART_REG_BAUD, quot | BAUD_MODE2);
+	serial_out(up, UART_REG_LCR, lcr);
+	spin_unlock_irqrestore(&up->port.lock, flags);
+}
...

+/*
+ *  Print a string to the serial port trying not to disturb
+ *  any possible real use of the port...
+ *
+ *  The console_lock must be held when we get here.
+ */
+static void ma35d1serial_console_write(struct console *co,
+				       const char *s, u32 count)
+{
+	struct uart_ma35d1_port *up = &ma35d1serial_ports[co->index];
+	unsigned long flags;
+	u32 ier;
+
+	local_irq_save(flags);

This doesn't protect access to the registers on other CPUs.

+
+	/*
+	 *  First save the IER then disable the interrupts
+	 */
+	ier = serial_in(up, UART_REG_IER);
+	serial_out(up, UART_REG_IER, 0);
+
+	uart_console_write(&up->port, s, count, ma35d1serial_console_putchar);
+
+	wait_for_xmitr(up);
+
+	serial_out(up, UART_REG_IER, ier);
+	local_irq_restore(flags);
+}
+
+static int __init ma35d1serial_console_setup(struct console *co,
+					     char *options)
+{
+	struct device_node *np = ma35d1serial_uart_nodes[co->index];
+	struct uart_ma35d1_port *p = &ma35d1serial_ports[co->index];
+	u32 val32[4];
+	struct uart_port *port;
+	int baud = 115200;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';

If you don't do uart_parse_options() (why you don't?), you don't need the variables.

+	/*
+	 * Check whether an invalid uart number has been specified, and
+	 * if so, search for the first available port that does have
+	 * console support.
+	 */
+	if ((co->index < 0) || (co->index >= UART_NR)) {
+		pr_debug("Console Port%x out of range\n", co->index);
+		return -EINVAL;
+	}
+
+	if (of_property_read_u32_array(np, "reg", val32, 4) != 0)
+		return -EINVAL;
+	p->port.iobase = val32[1];
+	p->port.membase = ioremap(p->port.iobase, UART_REG_SIZE);
+	p->port.ops = &ma35d1serial_ops;
+	p->port.line = 0;
+	p->port.uartclk = UART_CONSOLE_CLK;
+
+	port = &ma35d1serial_ports[co->index].port;
+	return uart_set_options(port, co, baud, parity, bits, flow);
+}
...> +static void ma35d1serial_console_init_port(void)
+{
+	int i = 0;

unsigned

+	struct device_node *np;
+
+	for_each_matching_node(np, ma35d1_serial_of_match) {
+		if (ma35d1serial_uart_nodes[i] == NULL) {
+			of_node_get(np);
+			ma35d1serial_uart_nodes[i] = np;
+			i++;
+			if (i == UART_NR)
+				break;
+		}
+	}
+}

+/*
+ * Register a set of serial devices attached to a platform device.
+ * The list is terminated with a zero flags entry, which means we expect
+ * all entries to have at least UPF_BOOT_AUTOCONF set.
+ */
+static int ma35d1serial_probe(struct platform_device *pdev)
+{
+	struct resource *res_mem;
+	struct uart_ma35d1_port *up;
+	int ret = 0;
+	struct clk *clk;
+	int err;
+
+	if (pdev->dev.of_node) {
+		ret = of_alias_get_id(pdev->dev.of_node, "serial");
+		if (ret < 0) {
+			dev_err(&pdev->dev, "failed to get alias/pdev id, errno %d\n", ret);
+			return ret;
+		}
+	}
+	up = &ma35d1serial_ports[ret];
+	up->port.line = ret;
+	res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res_mem)
+		return -ENODEV;
+
+	up->port.iobase = res_mem->start;
+	up->port.membase = ioremap(up->port.iobase, UART_REG_SIZE);
+	up->port.ops = &ma35d1serial_ops;
+
+	spin_lock_init(&up->port.lock);
+
+	clk = of_clk_get(pdev->dev.of_node, 0);
+	if (IS_ERR(clk)) {
+		err = PTR_ERR(clk);
+		dev_err(&pdev->dev, "failed to get core clk: %d\n", err);
+		return -ENOENT;

iounmap(membase) missing.

+	}
+	err = clk_prepare_enable(clk);
+	if (err)
+		return -ENOENT;

Dtto.

+
+	if (up->port.line != 0)
+		up->port.uartclk = clk_get_rate(clk);
+	up->port.irq = platform_get_irq(pdev, 0);

What if this fails?

+	up->port.dev = &pdev->dev;
+	up->port.flags = UPF_BOOT_AUTOCONF;
+	ret = uart_add_one_port(&ma35d1serial_reg, &up->port);

And this?

+	platform_set_drvdata(pdev, up);
+	return 0;
+}
+
+/*
+ * Remove serial ports registered against a platform device.
+ */
+static int ma35d1serial_remove(struct platform_device *dev)
+{
+	struct uart_port *port = platform_get_drvdata(dev);
+
+	uart_remove_one_port(&ma35d1serial_reg, port);
+	free_irq(port->irq, port);

You do this in ma35d1serial_shutdown() already, correct? So this will error out, right?

+	return 0;
+}

Just a couple of questions about testing. Have you tried to:
* remove the module?
* suspend/resume the machine while having a line active (device node opened)? * running at least a lockdep-enabled kernel while using the device extensively?

thanks,
--
js
suse labs




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