[PATCH v3 09/25] tty: serial: Add Actions Semi Owl UART earlycon

2017-02-27 Thread Andreas Färber 
This implements an earlycon for Actions Semi S500/S900 SoCs.

Based on LeMaker linux-actions tree.

Signed-off-by: Andreas Färber 
---
 v2 -> v3:
 * Adopted BIT() macro
 
 v1 -> v2:
 * Extended Kconfig help to mention earlycon (Arnd)
 * Spelled out Actions Semiconductor in Kconfig help
 * Adopted "actions" vendor prefix
 
 drivers/tty/serial/Kconfig|  19 ++
 drivers/tty/serial/Makefile   |   1 +
 drivers/tty/serial/owl-uart.c | 135 ++
 3 files changed, 155 insertions(+)
 create mode 100644 drivers/tty/serial/owl-uart.c

diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
index 6117ac8..e145822 100644
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig
@@ -1677,6 +1677,25 @@ config SERIAL_MVEBU_CONSOLE
  and warnings and which allows logins in single user mode)
  Otherwise, say 'N'.
 
+config SERIAL_OWL
+   bool "Actions Semi Owl serial port support"
+   depends on ARCH_ACTIONS || COMPILE_TEST
+   select SERIAL_CORE
+   help
+ This driver is for Actions Semiconductor S500/S900 SoC's UART.
+ Say 'Y' here if you wish to use the on-board serial port.
+ Otherwise, say 'N'.
+
+config SERIAL_OWL_CONSOLE
+   bool "Console on Actions Semi Owl serial port"
+   depends on SERIAL_OWL=y
+   select SERIAL_CORE_CONSOLE
+   select SERIAL_EARLYCON
+   default y
+   help
+ Say 'Y' here if you wish to use Actions Semiconductor S500/S900 UART
+ as the system console. Only earlycon is implemented currently.
+
 endmenu
 
 config SERIAL_MCTRL_GPIO
diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile
index 2d6288b..91f3571 100644
--- a/drivers/tty/serial/Makefile
+++ b/drivers/tty/serial/Makefile
@@ -91,6 +91,7 @@ obj-$(CONFIG_SERIAL_STM32)+= stm32-usart.o
 obj-$(CONFIG_SERIAL_MVEBU_UART)+= mvebu-uart.o
 obj-$(CONFIG_SERIAL_PIC32) += pic32_uart.o
 obj-$(CONFIG_SERIAL_MPS2_UART) += mps2-uart.o
+obj-$(CONFIG_SERIAL_OWL)   += owl-uart.o
 
 # GPIOLIB helpers for modem control lines
 obj-$(CONFIG_SERIAL_MCTRL_GPIO)+= serial_mctrl_gpio.o
diff --git a/drivers/tty/serial/owl-uart.c b/drivers/tty/serial/owl-uart.c
new file mode 100644
index 000..1b80087
--- /dev/null
+++ b/drivers/tty/serial/owl-uart.c
@@ -0,0 +1,135 @@
+/*
+ * Actions Semi Owl family serial console
+ *
+ * Copyright 2013 Actions Semi Inc.
+ * Author: Actions Semi, Inc.
+ *
+ * Copyright (c) 2016-2017 Andreas Färber
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see .
+ */
+
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+
+#define OWL_UART_CTL   0x000
+#define OWL_UART_TXDAT 0x008
+#define OWL_UART_STAT  0x00c
+
+#define OWL_UART_CTL_TRFS_TX   BIT(14)
+#define OWL_UART_CTL_ENBIT(15)
+#define OWL_UART_CTL_RXIE  BIT(18)
+#define OWL_UART_CTL_TXIE  BIT(19)
+
+#define OWL_UART_STAT_RIP  BIT(0)
+#define OWL_UART_STAT_TIP  BIT(1)
+#define OWL_UART_STAT_TFFU BIT(6)
+#define OWL_UART_STAT_TRFL_MASK(0x1f << 11)
+#define OWL_UART_STAT_UTBB BIT(17)
+
+static inline void owl_uart_write(struct uart_port *port, u32 val, unsigned 
int off)
+{
+   writel(val, port->membase + off);
+}
+
+static inline u32 owl_uart_read(struct uart_port *port, unsigned int off)
+{
+   return readl(port->membase + off);
+}
+
+#ifdef CONFIG_SERIAL_OWL_CONSOLE
+
+static void owl_console_putchar(struct uart_port *port, int ch)
+{
+   if (!port->membase)
+   return;
+
+   while (owl_uart_read(port, OWL_UART_STAT) & OWL_UART_STAT_TFFU)
+   cpu_relax();
+
+   owl_uart_write(port, ch, OWL_UART_TXDAT);
+}
+
+static void owl_uart_port_write(struct uart_port *port, const char *s,
+   u_int count)
+{
+   u32 old_ctl, val;
+   unsigned long flags;
+   int locked;
+
+   local_irq_save(flags);
+
+   if (port->sysrq)
+   locked = 0;
+   else if (oops_in_progress)
+   locked = spin_trylock(>lock);
+   else {
+   spin_lock(>lock);
+   locked = 1;
+   }
+
+   old_ctl = owl_uart_read(port, OWL_UART_CTL);
+   val = old_ctl | OWL_UART_CTL_TRFS_TX;
+   /* disable IRQ

[PATCH v3 09/25] tty: serial: Add Actions Semi Owl UART earlycon

2017-02-27 Thread Andreas Färber 
This implements an earlycon for Actions Semi S500/S900 SoCs.

Based on LeMaker linux-actions tree.

Signed-off-by: Andreas Färber 
---
 v2 -> v3:
 * Adopted BIT() macro
 
 v1 -> v2:
 * Extended Kconfig help to mention earlycon (Arnd)
 * Spelled out Actions Semiconductor in Kconfig help
 * Adopted "actions" vendor prefix
 
 drivers/tty/serial/Kconfig|  19 ++
 drivers/tty/serial/Makefile   |   1 +
 drivers/tty/serial/owl-uart.c | 135 ++
 3 files changed, 155 insertions(+)
 create mode 100644 drivers/tty/serial/owl-uart.c

diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
index 6117ac8..e145822 100644
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig
@@ -1677,6 +1677,25 @@ config SERIAL_MVEBU_CONSOLE
  and warnings and which allows logins in single user mode)
  Otherwise, say 'N'.
 
+config SERIAL_OWL
+   bool "Actions Semi Owl serial port support"
+   depends on ARCH_ACTIONS || COMPILE_TEST
+   select SERIAL_CORE
+   help
+ This driver is for Actions Semiconductor S500/S900 SoC's UART.
+ Say 'Y' here if you wish to use the on-board serial port.
+ Otherwise, say 'N'.
+
+config SERIAL_OWL_CONSOLE
+   bool "Console on Actions Semi Owl serial port"
+   depends on SERIAL_OWL=y
+   select SERIAL_CORE_CONSOLE
+   select SERIAL_EARLYCON
+   default y
+   help
+ Say 'Y' here if you wish to use Actions Semiconductor S500/S900 UART
+ as the system console. Only earlycon is implemented currently.
+
 endmenu
 
 config SERIAL_MCTRL_GPIO
diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile
index 2d6288b..91f3571 100644
--- a/drivers/tty/serial/Makefile
+++ b/drivers/tty/serial/Makefile
@@ -91,6 +91,7 @@ obj-$(CONFIG_SERIAL_STM32)+= stm32-usart.o
 obj-$(CONFIG_SERIAL_MVEBU_UART)+= mvebu-uart.o
 obj-$(CONFIG_SERIAL_PIC32) += pic32_uart.o
 obj-$(CONFIG_SERIAL_MPS2_UART) += mps2-uart.o
+obj-$(CONFIG_SERIAL_OWL)   += owl-uart.o
 
 # GPIOLIB helpers for modem control lines
 obj-$(CONFIG_SERIAL_MCTRL_GPIO)+= serial_mctrl_gpio.o
diff --git a/drivers/tty/serial/owl-uart.c b/drivers/tty/serial/owl-uart.c
new file mode 100644
index 000..1b80087
--- /dev/null
+++ b/drivers/tty/serial/owl-uart.c
@@ -0,0 +1,135 @@
+/*
+ * Actions Semi Owl family serial console
+ *
+ * Copyright 2013 Actions Semi Inc.
+ * Author: Actions Semi, Inc.
+ *
+ * Copyright (c) 2016-2017 Andreas Färber
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see .
+ */
+
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+
+#define OWL_UART_CTL   0x000
+#define OWL_UART_TXDAT 0x008
+#define OWL_UART_STAT  0x00c
+
+#define OWL_UART_CTL_TRFS_TX   BIT(14)
+#define OWL_UART_CTL_ENBIT(15)
+#define OWL_UART_CTL_RXIE  BIT(18)
+#define OWL_UART_CTL_TXIE  BIT(19)
+
+#define OWL_UART_STAT_RIP  BIT(0)
+#define OWL_UART_STAT_TIP  BIT(1)
+#define OWL_UART_STAT_TFFU BIT(6)
+#define OWL_UART_STAT_TRFL_MASK(0x1f << 11)
+#define OWL_UART_STAT_UTBB BIT(17)
+
+static inline void owl_uart_write(struct uart_port *port, u32 val, unsigned 
int off)
+{
+   writel(val, port->membase + off);
+}
+
+static inline u32 owl_uart_read(struct uart_port *port, unsigned int off)
+{
+   return readl(port->membase + off);
+}
+
+#ifdef CONFIG_SERIAL_OWL_CONSOLE
+
+static void owl_console_putchar(struct uart_port *port, int ch)
+{
+   if (!port->membase)
+   return;
+
+   while (owl_uart_read(port, OWL_UART_STAT) & OWL_UART_STAT_TFFU)
+   cpu_relax();
+
+   owl_uart_write(port, ch, OWL_UART_TXDAT);
+}
+
+static void owl_uart_port_write(struct uart_port *port, const char *s,
+   u_int count)
+{
+   u32 old_ctl, val;
+   unsigned long flags;
+   int locked;
+
+   local_irq_save(flags);
+
+   if (port->sysrq)
+   locked = 0;
+   else if (oops_in_progress)
+   locked = spin_trylock(>lock);
+   else {
+   spin_lock(>lock);
+   locked = 1;
+   }
+
+   old_ctl = owl_uart_read(port, OWL_UART_CTL);
+   val = old_ctl | OWL_UART_CTL_TRFS_TX;
+   /* disable IRQ */
+   val &=