On 2014-11-25 at 13:16:58 +0100, Chunyan Zhang [off-list ref] wrote:

Add a full sc9836-uart driver for SC9836 SoC which is based on the
spreadtrum sharkl64 platform.
This driver also support earlycon.

Signed-off-by: Chunyan Zhang <redacted>
Signed-off-by: Orson Zhai <redacted>
Originally-by: Lanqing Liu [off-list ref]
---
 Documentation/devices.txt        |    3 +
 drivers/tty/serial/Kconfig       |   23 ++
 drivers/tty/serial/Makefile      |    1 +
 drivers/tty/serial/sprd_serial.c |  752 ++++++++++++++++++++++++++++++++++++++
 include/uapi/linux/serial_core.h |    3 +
 5 files changed, 782 insertions(+)
 create mode 100644 drivers/tty/serial/sprd_serial.c

[...]

Please consistently use tabs instead of spaces for indentation. The help
text should be indented by one tabe + 2 spaces.

[...]

[...]

+static inline int handle_lsr_errors(struct uart_port *port,
+	unsigned int *flag, unsigned int *lsr)

This line should be aligned with the opening ( above.

+{
+	int ret = 0;
+
+	/* stastics */
+	if (*lsr & SPRD_LSR_BI) {
+		*lsr &= ~(SPRD_LSR_FE | SPRD_LSR_PE);
+		port->icount.brk++;
+		ret = uart_handle_break(port);
+		if (ret)
+			return ret;
+	} else if (*lsr & SPRD_LSR_PE)
+		port->icount.parity++;
+	else if (*lsr & SPRD_LSR_FE)
+		port->icount.frame++;
+	if (*lsr & SPRD_LSR_OE)
+		port->icount.overrun++;
+
+	/* mask off conditions which should be ignored */
+	*lsr &= port->read_status_mask;
+	if (*lsr & SPRD_LSR_BI)
+		*flag = TTY_BREAK;
+	else if (*lsr & SPRD_LSR_PE)
+		*flag = TTY_PARITY;
+	else if (*lsr & SPRD_LSR_FE)
+		*flag = TTY_FRAME;
+
+	return ret;
+}
+
+static inline void sprd_rx(int irq, void *dev_id)
+{
+	struct uart_port *port = (struct uart_port *)dev_id;

No need to cast a void pointer.

+	struct tty_port *tty = &port->state->port;
+	unsigned int ch, flag, lsr, max_count = 2048;
+
+	while ((serial_in(port, SPRD_STS1) & 0x00ff) && max_count--) {
+		lsr = serial_in(port, SPRD_LSR);
+		ch = serial_in(port, SPRD_RXD);
+		flag = TTY_NORMAL;
+		port->icount.rx++;
+
+		if (unlikely(lsr & (SPRD_LSR_BI | SPRD_LSR_PE
+				| SPRD_LSR_FE | SPRD_LSR_OE)))
+			if (handle_lsr_errors(port, &lsr, &flag))
+				continue;
+		if (uart_handle_sysrq_char(port, ch))
+			continue;
+
+		uart_insert_char(port, lsr, SPRD_LSR_OE, ch, flag);
+	}
+
+	tty_flip_buffer_push(tty);
+}

[...]

+static void sprd_console_write(struct console *co, const char *s,
+				      unsigned int count)
+{
+	struct uart_port *port = (struct uart_port *)sprd_port[co->index];

Better explicitly access the .port member of sprd_port[co->index] here
instead of casting.

+	int ien;
+	int locked = 1;
+
+	if (oops_in_progress)
+		locked = spin_trylock(&port->lock);
+	else
+		spin_lock(&port->lock);
+	/* save the IEN then disable the interrupts */
+	ien = serial_in(port, SPRD_IEN);
+	serial_out(port, SPRD_IEN, 0x0);
+
+	uart_console_write(port, s, count, sprd_console_putchar);
+
+	/* wait for transmitter to become empty and restore the IEN */
+	wait_for_xmitr(port);
+	serial_out(port, SPRD_IEN, ien);
+	if (locked)
+		spin_unlock(&port->lock);
+}
+
+static int __init sprd_console_setup(struct console *co, char *options)
+{
+	struct uart_port *port;
+	int baud = 115200;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	if (unlikely(co->index >= UART_NR_MAX || co->index < 0))
+		co->index = 0;
+
+	port = (struct uart_port *)sprd_port[co->index];

Same here, use the .port member of struct sprd_port[co->index].

+	if (port == NULL) {
+		pr_info("srial port %d not yet initialized\n", co->index);

Typo: should be serial instead of srial.

+		return -ENODEV;
+	}
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	return uart_set_options(port, co, baud, parity, bits, flow);
+}

[...]

+static int sprd_probe(struct platform_device *pdev)
+{
+	struct resource *mem;
+	struct device_node *np = pdev->dev.of_node;
+	struct uart_port *up;
+	struct clk *clk;
+	int irq;
+
+
+	if (np)
+		pdev->id = of_alias_get_id(np, "serial");
+
+	if (unlikely(pdev->id < 0 || pdev->id >= UART_NR_MAX)) {
+		dev_err(&pdev->dev, "does not support id %d\n", pdev->id);
+		return -ENXIO;
+	}
+
+	sprd_port[pdev->id] = devm_kzalloc(&pdev->dev,
+		sizeof(*sprd_port[pdev->id]), GFP_KERNEL);
+	if (!sprd_port[pdev->id])
+		return -ENOMEM;
+
+	up = (struct uart_port *)sprd_port[pdev->id];
+	up->dev = &pdev->dev;
+	up->line = pdev->id;
+	up->type = PORT_SPRD;
+	up->iotype = SERIAL_IO_PORT;
+	up->uartclk = SPRD_DEF_RATE;
+	up->fifosize = SPRD_FIFO_SIZE;
+	up->ops = &serial_sprd_ops;
+	up->flags = ASYNC_BOOT_AUTOCONF;
+
+	clk = devm_clk_get(&pdev->dev, NULL);
+	if (!IS_ERR(clk))
+		up->uartclk = clk_get_rate(clk);
+
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (unlikely(!mem)) {
+		dev_err(&pdev->dev, "not provide mem resource\n");
+		return -ENODEV;
+	}
+	up->mapbase = mem->start;
+	up->membase = ioremap(mem->start, resource_size(mem));

Return value of ioremap() should be checked for NULL.

+
+	irq = platform_get_irq(pdev, 0);
+	if (unlikely(irq < 0)) {
+		dev_err(&pdev->dev, "not provide irq resource\n");
+		return -ENODEV;
+	}
+	up->irq = irq;
+
+	platform_set_drvdata(pdev, up);
+
+	return uart_add_one_port(&sprd_uart_driver, up);
+}
+
+static int sprd_remove(struct platform_device *dev)
+{
+	struct uart_port *up = platform_get_drvdata(dev);
+
+	return uart_remove_one_port(&sprd_uart_driver, up);
+}
+
+static int sprd_suspend(struct platform_device *dev, pm_message_t state)
+{
+	int id = dev->id;
+	struct uart_port *port = (struct uart_port *)sprd_port[id];
+	struct reg_backup *reg_bak = &(sprd_port[id]->reg_bak);
+
+	reg_bak->ien = serial_in(port, SPRD_IEN);
+	reg_bak->ctrl0 = serial_in(port, SPRD_LCR);
+	reg_bak->ctrl1 = serial_in(port, SPRD_CTL1);
+	reg_bak->ctrl2 = serial_in(port, SPRD_CTL2);
+	reg_bak->clkd0 = serial_in(port, SPRD_CLKD0);
+	reg_bak->clkd1 = serial_in(port, SPRD_CLKD1);
+
+	return 0;
+}
+
+static int sprd_resume(struct platform_device *dev)
+{
+	int id = dev->id;
+	struct uart_port *port = (struct uart_port *)sprd_port[id];

Access the .port member instead of the cast.

+	struct reg_backup *reg_bak = &(sprd_port[id]->reg_bak);
+
+	serial_out(port, SPRD_LCR, reg_bak->ctrl0);
+	serial_out(port, SPRD_CTL1, reg_bak->ctrl1);
+	serial_out(port, SPRD_CTL2, reg_bak->ctrl2);
+	serial_out(port, SPRD_CLKD0, reg_bak->clkd0);
+	serial_out(port, SPRD_CLKD1, reg_bak->clkd1);
+	serial_out(port, SPRD_IEN, reg_bak->ien);
+
+	return 0;
+}