Merge tag 'tty-3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel…

…/git/gregkh/tty

Pull tty/serial driver update from Greg KH:
 "Here's the big tty/serial driver update for 3.15-rc1.

  Nothing major, a number of serial driver updates and a few tty core
  fixes as well.

  All have been in linux-next for a while"

* tag 'tty-3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (71 commits)
  tty/serial: omap: empty the RX FIFO at the end of half-duplex TX
  tty/serial: omap: fix RX interrupt enable/disable in half-duplex TX
  serial: sh-sci: Neaten dev_<level> uses
  serial: sh-sci: Replace hardcoded 3 by UART_PM_STATE_OFF
  serial: sh-sci: Add more register documentation
  serial: sh-sci: Remove useless casts
  serial: sh-sci: Replace printk() by pr_*()
  serial_core: Avoid NULL pointer dereference in uart_close()
  serial_core: Get a reference for port->tty in uart_remove_one_port()
  serial: clps711x: Give a chance to perform useful tasks during wait loop
  serial_core: Grammar s/ports/port's/
  serial_core: Spelling s/contro/control/
  serial: efm32: properly namespace location property
  serial: max310x: Add missing #include <linux/uaccess.h>
  synclink: fix info leak in ioctl
  serial: 8250: Clean up the locking for -rt
  serial: 8250_pci: change BayTrail default uartclk
  serial: 8250_pci: more BayTrail error-free bauds
  serial: sh-sci: Add missing call to uart_remove_one_port() in failure path
  serial_core: Unregister console in uart_remove_one_port()
  ...

Documentation/devicetree/bindings/serial/efm32-uart.txt

@@ -6,7 +6,7 @@ Required properties:
 - interrupts : Should contain uart interrupt
 
 Optional properties:
-- location : Decides the location of the USART I/O pins.
+- efm32,location : Decides the location of the USART I/O pins.
   Allowed range : [0 .. 5]
   Default: 0
 
@@ -16,5 +16,5 @@ uart@0x4000c400 {
 	compatible = "efm32,uart";
 	reg = <0x4000c400 0x400>;
 	interrupts = <15>;
-	location = <0>;
+	efm32,location = <0>;
 };

Documentation/devicetree/bindings/serial/fsl-lpuart.txt

@@ -4,11 +4,24 @@ Required properties:
 - compatible : Should be "fsl,<soc>-lpuart"
 - reg : Address and length of the register set for the device
 - interrupts : Should contain uart interrupt
+- clocks : phandle + clock specifier pairs, one for each entry in clock-names
+- clock-names : should contain: "ipg" - the uart clock
+
+Optional properties:
+- dmas: A list of two dma specifiers, one for each entry in dma-names.
+- dma-names: should contain "tx" and "rx".
+
+Note: Optional properties for DMA support. Write them both or both not.
 
 Example:
 
 uart0: serial@40027000 {
-	       compatible = "fsl,vf610-lpuart";
-	       reg = <0x40027000 0x1000>;
-	       interrupts = <0 61 0x00>;
-       };
+		compatible = "fsl,vf610-lpuart";
+		reg = <0x40027000 0x1000>;
+		interrupts = <0 61 0x00>;
+		clocks = <&clks VF610_CLK_UART0>;
+		clock-names = "ipg";
+		dmas = <&edma0 0 2>,
+			<&edma0 0 3>;
+		dma-names = "rx","tx";
+	};

Documentation/devicetree/bindings/serial/maxim,max310x.txt

@@ -0,0 +1,36 @@
+* Maxim MAX310X advanced Universal Asynchronous Receiver-Transmitter (UART)
+
+Required properties:
+- compatible: Should be one of the following:
+  - "maxim,max3107" for Maxim MAX3107,
+  - "maxim,max3108" for Maxim MAX3108,
+  - "maxim,max3109" for Maxim MAX3109,
+  - "maxim,max14830" for Maxim MAX14830.
+- reg: SPI chip select number.
+- interrupt-parent: The phandle for the interrupt controller that
+  services interrupts for this IC.
+- interrupts: Specifies the interrupt source of the parent interrupt
+  controller. The format of the interrupt specifier depends on the
+  parent interrupt controller.
+- clocks: phandle to the IC source clock.
+- clock-names: Should be "xtal" if clock is an external crystal or
+  "osc" if an external clock source is used.
+
+Optional properties:
+- gpio-controller: Marks the device node as a GPIO controller.
+- #gpio-cells: Should be two. The first cell is the GPIO number and
+  the second cell is used to specify the GPIO polarity:
+    0 = active high,
+    1 = active low.
+
+Example:
+	max14830: max14830@0 {
+		compatible = "maxim,max14830";
+		reg = <0>;
+		clocks = <&clk20m>;
+		clock-names = "osc";
+		interrupt-parent = <&gpio3>;
+		interrupts = <7 IRQ_TYPE_EDGE_FALLING>;
+		gpio-controller;
+		#gpio-cells = <2>;
+	};

Documentation/devicetree/bindings/serial/renesas,sci-serial.txt

@@ -37,7 +37,7 @@ Example:
 	};
 
 	scifa0: serial@e6c40000 {
-		compatible = "renesas,scifa-r8a7790", "renesas,scifa-generic";
+		compatible = "renesas,scifa-r8a7790", "renesas,scifa";
 		reg = <0 0xe6c40000 0 64>;
 		interrupt-parent = <&gic>;
 		interrupts = <0 144 IRQ_TYPE_LEVEL_HIGH>;

arch/arm/boot/dts/atlas6.dtsi

@@ -217,8 +217,8 @@
 				interrupts = <17>;
 				fifosize = <128>;
 				clocks = <&clks 13>;
-				sirf,uart-dma-rx-channel = <21>;
-				sirf,uart-dma-tx-channel = <2>;
+				dmas = <&dmac1 5>, <&dmac0 2>;
+				dma-names = "rx", "tx";
 			};
 
 			uart1: uart@b0060000 {
@@ -228,6 +228,7 @@
 				interrupts = <18>;
 				fifosize = <32>;
 				clocks = <&clks 14>;
+				dma-names = "no-rx", "no-tx";
 			};
 
 			uart2: uart@b0070000 {
@@ -237,8 +238,8 @@
 				interrupts = <19>;
 				fifosize = <128>;
 				clocks = <&clks 15>;
-				sirf,uart-dma-rx-channel = <6>;
-				sirf,uart-dma-tx-channel = <7>;
+				dmas = <&dmac0 6>, <&dmac0 7>;
+				dma-names = "rx", "tx";
 			};
 
 			usp0: usp@b0080000 {
@@ -248,8 +249,8 @@
 				interrupts = <20>;
 				fifosize = <128>;
 				clocks = <&clks 28>;
-				sirf,usp-dma-rx-channel = <17>;
-				sirf,usp-dma-tx-channel = <18>;
+				dmas = <&dmac1 1>, <&dmac1 2>;
+				dma-names = "rx", "tx";
 			};
 
 			usp1: usp@b0090000 {
@@ -259,8 +260,8 @@
 				interrupts = <21>;
 				fifosize = <128>;
 				clocks = <&clks 29>;
-				sirf,usp-dma-rx-channel = <14>;
-				sirf,usp-dma-tx-channel = <15>;
+				dmas = <&dmac0 14>, <&dmac0 15>;
+				dma-names = "rx", "tx";
 			};
 
 			dmac0: dma-controller@b00b0000 {

arch/arm/boot/dts/prima2.dtsi

@@ -223,8 +223,8 @@
 				interrupts = <17>;
 				fifosize = <128>;
 				clocks = <&clks 13>;
-				sirf,uart-dma-rx-channel = <21>;
-				sirf,uart-dma-tx-channel = <2>;
+				dmas = <&dmac1 5>, <&dmac0 2>;
+				dma-names = "rx", "tx";
 			};
 
 			uart1: uart@b0060000 {
@@ -243,8 +243,8 @@
 				interrupts = <19>;
 				fifosize = <128>;
 				clocks = <&clks 15>;
-				sirf,uart-dma-rx-channel = <6>;
-				sirf,uart-dma-tx-channel = <7>;
+				dmas = <&dmac0 6>, <&dmac0 7>;
+				dma-names = "rx", "tx";
 			};
 
 			usp0: usp@b0080000 {
@@ -254,8 +254,8 @@
 				interrupts = <20>;
 				fifosize = <128>;
 				clocks = <&clks 28>;
-				sirf,usp-dma-rx-channel = <17>;
-				sirf,usp-dma-tx-channel = <18>;
+				dmas = <&dmac1 1>, <&dmac1 2>;
+				dma-names = "rx", "tx";
 			};
 
 			usp1: usp@b0090000 {
@@ -265,8 +265,8 @@
 				interrupts = <21>;
 				fifosize = <128>;
 				clocks = <&clks 29>;
-				sirf,usp-dma-rx-channel = <14>;
-				sirf,usp-dma-tx-channel = <15>;
+				dmas = <&dmac0 14>, <&dmac0 15>;
+				dma-names = "rx", "tx";
 			};
 
 			usp2: usp@b00a0000 {
@@ -276,8 +276,8 @@
 				interrupts = <22>;
 				fifosize = <128>;
 				clocks = <&clks 30>;
-				sirf,usp-dma-rx-channel = <10>;
-				sirf,usp-dma-tx-channel = <11>;
+				dmas = <&dmac0 10>, <&dmac0 11>;
+				dma-names = "rx", "tx";
 			};
 
 			dmac0: dma-controller@b00b0000 {

arch/arm/mach-imx/mach-mx31moboard.c

@@ -128,27 +128,15 @@ static struct platform_device mx31moboard_flash = {
 	.num_resources = 1,
 };
 
-static int moboard_uart0_init(struct platform_device *pdev)
+static void __init moboard_uart0_init(void)
 {
-	int ret = gpio_request(IOMUX_TO_GPIO(MX31_PIN_CTS1), "uart0-cts-hack");
-	if (ret)
-		return ret;
-
-	ret = gpio_direction_output(IOMUX_TO_GPIO(MX31_PIN_CTS1), 0);
-	if (ret)
+	if (!gpio_request(IOMUX_TO_GPIO(MX31_PIN_CTS1), "uart0-cts-hack")) {
+		gpio_direction_output(IOMUX_TO_GPIO(MX31_PIN_CTS1), 0);
 		gpio_free(IOMUX_TO_GPIO(MX31_PIN_CTS1));
-
-	return ret;
-}
-
-static void moboard_uart0_exit(struct platform_device *pdev)
-{
-	gpio_free(IOMUX_TO_GPIO(MX31_PIN_CTS1));
+	}
 }
 
 static const struct imxuart_platform_data uart0_pdata __initconst = {
-	.init = moboard_uart0_init,
-	.exit = moboard_uart0_exit,
 };
 
 static const struct imxuart_platform_data uart4_pdata __initconst = {
@@ -543,6 +531,7 @@ static void __init mx31moboard_init(void)
 
 	imx31_add_imx2_wdt();
 
+	moboard_uart0_init();
 	imx31_add_imx_uart0(&uart0_pdata);
 	imx31_add_imx_uart4(&uart4_pdata);
 

drivers/tty/hvc/hvc_console.c

@@ -31,6 +31,7 @@
 #include <linux/list.h>
 #include <linux/module.h>
 #include <linux/major.h>
+#include <linux/atomic.h>
 #include <linux/sysrq.h>
 #include <linux/tty.h>
 #include <linux/tty_flip.h>
@@ -70,6 +71,9 @@ static struct task_struct *hvc_task;
 /* Picks up late kicks after list walk but before schedule() */
 static int hvc_kicked;
 
+/* hvc_init is triggered from hvc_alloc, i.e. only when actually used */
+static atomic_t hvc_needs_init __read_mostly = ATOMIC_INIT(-1);
+
 static int hvc_init(void);
 
 #ifdef CONFIG_MAGIC_SYSRQ
@@ -851,7 +855,7 @@ struct hvc_struct *hvc_alloc(uint32_t vtermno, int data,
 	int i;
 
 	/* We wait until a driver actually comes along */
-	if (!hvc_driver) {
+	if (atomic_inc_not_zero(&hvc_needs_init)) {
 		int err = hvc_init();
 		if (err)
 			return ERR_PTR(err);

drivers/tty/ipwireless/tty.c

@@ -176,9 +176,6 @@ void ipwireless_tty_received(struct ipw_tty *tty, unsigned char *data,
 				": %d chars not inserted to flip buffer!\n",
 				length - work);
 
-	/*
-	 * This may sleep if ->low_latency is set
-	 */
 	if (work)
 		tty_flip_buffer_push(&tty->port);
 }

drivers/tty/n_tty.c

@@ -1900,13 +1900,10 @@ static inline int input_available_p(struct tty_struct *tty, int poll)
 	struct n_tty_data *ldata = tty->disc_data;
 	int amt = poll && !TIME_CHAR(tty) && MIN_CHAR(tty) ? MIN_CHAR(tty) : 1;
 
-	if (ldata->icanon && !L_EXTPROC(tty)) {
-		if (ldata->canon_head != ldata->read_tail)
-			return 1;
-	} else if (read_cnt(ldata) >= amt)
-		return 1;
-
-	return 0;
+	if (ldata->icanon && !L_EXTPROC(tty))
+		return ldata->canon_head != ldata->read_tail;
+	else
+		return read_cnt(ldata) >= amt;
 }
 
 /**

drivers/tty/serial/8250/8250_core.c

@@ -1694,6 +1694,10 @@ static int serial_link_irq_chain(struct uart_8250_port *up)
 
 static void serial_unlink_irq_chain(struct uart_8250_port *up)
 {
+	/*
+	 * yes, some broken gcc emit "warning: 'i' may be used uninitialized"
+	 * but no, we are not going to take a patch that assigns NULL below.
+	 */
 	struct irq_info *i;
 	struct hlist_node *n;
 	struct hlist_head *h;
@@ -2882,14 +2886,10 @@ serial8250_console_write(struct console *co, const char *s, unsigned int count)
 
 	touch_nmi_watchdog();
 
-	local_irq_save(flags);
-	if (port->sysrq) {
-		/* serial8250_handle_irq() already took the lock */
-		locked = 0;
-	} else if (oops_in_progress) {
-		locked = spin_trylock(&port->lock);
-	} else
-		spin_lock(&port->lock);
+	if (port->sysrq || oops_in_progress)
+		locked = spin_trylock_irqsave(&port->lock, flags);
+	else
+		spin_lock_irqsave(&port->lock, flags);
 
 	/*
 	 *	First save the IER then disable the interrupts
@@ -2921,8 +2921,7 @@ serial8250_console_write(struct console *co, const char *s, unsigned int count)
 		serial8250_modem_status(up);
 
 	if (locked)
-		spin_unlock(&port->lock);
-	local_irq_restore(flags);
+		spin_unlock_irqrestore(&port->lock, flags);
 }
 
 static int __init serial8250_console_setup(struct console *co, char *options)

drivers/tty/serial/8250/8250_pci.c

@@ -1366,23 +1366,44 @@ byt_set_termios(struct uart_port *p, struct ktermios *termios,
 		struct ktermios *old)
 {
 	unsigned int baud = tty_termios_baud_rate(termios);
-	unsigned int m = 6912;
-	unsigned int n = 15625;
+	unsigned int m, n;
 	u32 reg;
 
-	/* For baud rates 1M, 2M, 3M and 4M the dividers must be adjusted. */
-	if (baud == 1000000 || baud == 2000000 || baud == 4000000) {
+	/*
+	 * For baud rates 0.5M, 1M, 1.5M, 2M, 2.5M, 3M, 3.5M and 4M the
+	 * dividers must be adjusted.
+	 *
+	 * uartclk = (m / n) * 100 MHz, where m <= n
+	 */
+	switch (baud) {
+	case 500000:
+	case 1000000:
+	case 2000000:
+	case 4000000:
 		m = 64;
 		n = 100;
-
 		p->uartclk = 64000000;
-	} else if (baud == 3000000) {
+		break;
+	case 3500000:
+		m = 56;
+		n = 100;
+		p->uartclk = 56000000;
+		break;
+	case 1500000:
+	case 3000000:
 		m = 48;
 		n = 100;
-
 		p->uartclk = 48000000;
-	} else {
-		p->uartclk = 44236800;
+		break;
+	case 2500000:
+		m = 40;
+		n = 100;
+		p->uartclk = 40000000;
+		break;
+	default:
+		m = 2304;
+		n = 3125;
+		p->uartclk = 73728000;
 	}
 
 	/* Reset the clock */
@@ -3449,6 +3470,10 @@ static struct pciserial_board pci_boards[] = {
 		.base_baud	= 921600,
 		.reg_shift      = 2,
 	},
+	/*
+	 * Intel BayTrail HSUART reference clock is 44.2368 MHz at power-on,
+	 * but is overridden by byt_set_termios.
+	 */
 	[pbn_byt] = {
 		.flags		= FL_BASE0,
 		.num_ports	= 1,