[PATCH 4/4] xen/arm: enable ns16550 uart driver for OMAP5432

[Chen Baozi <baozich@gmail.com>]

Signed-off-by: Chen Baozi <baozich@gmail.com>
---
 xen/arch/arm/Rules.mk      |   1 +
 xen/drivers/char/ns16550.c | 155 +++++++++++++++++++++++++++++++++++++++------
 xen/include/asm-arm/io.h   |  49 ++++++++++++++
 xen/include/xen/serial.h   |   7 +-
 4 files changed, 191 insertions(+), 21 deletions(-)

diff --git a/xen/arch/arm/Rules.mk b/xen/arch/arm/Rules.mk
index eaa03fb..8604e34 100644
--- a/xen/arch/arm/Rules.mk
+++ b/xen/arch/arm/Rules.mk
@@ -9,6 +9,7 @@
 HAS_DEVICE_TREE := y
 HAS_VIDEO := y
 HAS_ARM_HDLCD := y
+HAS_NS16550 := y
 
 CFLAGS += -fno-builtin -fno-common -Wredundant-decls
 CFLAGS += -iwithprefix include -Werror -Wno-pointer-arith -pipe
diff --git a/xen/drivers/char/ns16550.c b/xen/drivers/char/ns16550.c
index 60512be..b8690eb 100644
--- a/xen/drivers/char/ns16550.c
+++ b/xen/drivers/char/ns16550.c
@@ -1,10 +1,10 @@
 /******************************************************************************
  * ns16550.c
- * 
+ *
  * Driver for 16550-series UARTs. This driver is to be kept within Xen as
  * it permits debugging of seriously-toasted machines (e.g., in situations
  * where a device driver within a guest OS would be inaccessible).
- * 
+ *
  * Copyright (c) 2003-2005, K A Fraser
  */
 
@@ -25,6 +25,13 @@
 #include <asm/fixmap.h>
 #endif
 
+#ifdef CONFIG_ARM
+#include <xen/device_tree.h>
+#include <xen/errno.h>
+#include <asm/early_printk.h>
+#include <asm/device.h>
+#endif
+
 /*
  * Configure serial port with a string:
  *   <baud>[/<clock_hz>][,DPS[,<io-base>[,<irq>[,<port-bdf>[,<bridge-bdf>]]]]].
@@ -39,8 +46,11 @@ string_param("com1", opt_com1);
 string_param("com2", opt_com2);
 
 static struct ns16550 {
-    int baud, clock_hz, data_bits, parity, stop_bits, fifo_size, irq;
-    unsigned long io_base;   /* I/O port or memory-mapped I/O address. */
+    int baud, data_bits, parity, stop_bits, fifo_size;
+    u32 clock_hz;
+    struct dt_irq irq;
+    u64 io_base;   /* I/O port or memory-mapped I/O address. */
+    u64 io_size;
     char __iomem *remapped_io_base;  /* Remapped virtual address of MMIO. */
     /* UART with IRQ line: interrupt-driven I/O. */
     struct irqaction irqaction;
@@ -61,16 +71,24 @@ static struct ns16550 {
 
 static char ns_read_reg(struct ns16550 *uart, int reg)
 {
+#ifdef CONFIG_X86
     if ( uart->remapped_io_base == NULL )
         return inb(uart->io_base + reg);
     return readb(uart->remapped_io_base + reg);
+#else
+    return readb(uart->remapped_io_base + (reg << 2));
+#endif
 }
 
 static void ns_write_reg(struct ns16550 *uart, int reg, char c)
 {
+#ifdef CONFIG_X86
     if ( uart->remapped_io_base == NULL )
         return outb(c, uart->io_base + reg);
     writeb(c, uart->remapped_io_base + reg);
+#else
+    writeb(c, uart->remapped_io_base + (reg << 2));
+#endif
 }
 
 static void ns16550_interrupt(
@@ -145,11 +163,12 @@ static int ns16550_getc(struct serial_port *port, char *pc)
     return 1;
 }
 
+#ifdef CONFIG_X86
 static void pci_serial_early_init(struct ns16550 *uart)
 {
     if ( !uart->ps_bdf_enable || uart->io_base >= 0x10000 )
         return;
-    
+
     if ( uart->pb_bdf_enable )
         pci_conf_write16(0, uart->pb_bdf[0], uart->pb_bdf[1], uart->pb_bdf[2],
                          PCI_IO_BASE,
@@ -161,7 +180,13 @@ static void pci_serial_early_init(struct ns16550 *uart)
                      uart->io_base | PCI_BASE_ADDRESS_SPACE_IO);
     pci_conf_write16(0, uart->ps_bdf[0], uart->ps_bdf[1], uart->ps_bdf[2],
                      PCI_COMMAND, PCI_COMMAND_IO);
+
+}
+#else
+static void pci_serial_early_init(struct ns16550 *uart)
+{
 }
+#endif
 
 static void ns16550_setup_preirq(struct ns16550 *uart)
 {
@@ -217,7 +242,9 @@ static void __init ns16550_init_preirq(struct serial_port *port)
         uart->remapped_io_base = (void __iomem *)fix_to_virt(idx);
         uart->remapped_io_base += uart->io_base & ~PAGE_MASK;
 #else
-        uart->remapped_io_base = (char *)ioremap(uart->io_base, 8);
+        uart->remapped_io_base = ioremap_attr(uart->io_base,
+                                              uart->io_size,
+                                              PAGE_HYPERVISOR_NOCACHE);
 #endif
     }
 
@@ -231,7 +258,7 @@ static void __init ns16550_init_preirq(struct serial_port *port)
 
 static void ns16550_setup_postirq(struct ns16550 *uart)
 {
-    if ( uart->irq > 0 )
+    if ( uart->irq.irq > 0 )
     {
         /* Master interrupt enable; also keep DTR/RTS asserted. */
         ns_write_reg(uart,
@@ -241,7 +268,7 @@ static void ns16550_setup_postirq(struct ns16550 *uart)
         ns_write_reg(uart, UART_IER, UART_IER_ERDAI | UART_IER_ELSI);
     }
 
-    if ( uart->irq >= 0 )
+    if ( uart->irq.irq >= 0 )
         set_timer(&uart->timer, NOW() + MILLISECS(uart->timeout_ms));
 }
 
@@ -250,7 +277,7 @@ static void __init ns16550_init_postirq(struct serial_port *port)
     struct ns16550 *uart = port->uart;
     int rc, bits;
 
-    if ( uart->irq < 0 )
+    if ( uart->irq.irq < 0 )
         return;
 
     serial_async_transmit(port);
@@ -262,20 +289,26 @@ static void __init ns16550_init_postirq(struct serial_port *port)
     uart->timeout_ms = max_t(
         unsigned int, 1, (bits * uart->fifo_size * 1000) / uart->baud);
 
-    if ( uart->irq > 0 )
+    if ( uart->irq.irq > 0 )
     {
         uart->irqaction.handler = ns16550_interrupt;
         uart->irqaction.name    = "ns16550";
         uart->irqaction.dev_id  = port;
-        if ( (rc = setup_irq(uart->irq, &uart->irqaction)) != 0 )
-            printk("ERROR: Failed to allocate ns16550 IRQ %d\n", uart->irq);
+#ifdef CONFIG_X86
+        if ( (rc = setup_irq(uart->irq.irq, &uart->irqaction)) != 0 )
+#else
+        if ( (rc = setup_dt_irq(&uart->irq, &uart->irqaction)) != 0 )
+#endif
+            printk("ERROR: Failed to allocate ns16550 IRQ %d\n", uart->irq.irq);
     }
 
     ns16550_setup_postirq(uart);
 
+#ifdef CONFIG_X86
     if ( uart->bar || uart->ps_bdf_enable )
         pci_hide_device(uart->ps_bdf[0], PCI_DEVFN(uart->ps_bdf[1],
                                                    uart->ps_bdf[2]));
+#endif
 }
 
 static void ns16550_suspend(struct serial_port *port)
@@ -284,13 +317,16 @@ static void ns16550_suspend(struct serial_port *port)
 
     stop_timer(&uart->timer);
 
+#ifdef CONFIG_X86
     if ( uart->bar )
        uart->cr = pci_conf_read16(0, uart->ps_bdf[0], uart->ps_bdf[1],
                                   uart->ps_bdf[2], PCI_COMMAND);
+#endif
 }
 
 static void _ns16550_resume(struct serial_port *port)
 {
+#ifdef CONFIG_X86
     struct ns16550 *uart = port->uart;
 
     if ( uart->bar )
@@ -300,6 +336,7 @@ static void _ns16550_resume(struct serial_port *port)
        pci_conf_write16(0, uart->ps_bdf[0], uart->ps_bdf[1], uart->ps_bdf[2],
                         PCI_COMMAND, uart->cr);
     }
+#endif
 
     ns16550_setup_preirq(port->uart);
     ns16550_setup_postirq(port->uart);
@@ -370,9 +407,17 @@ static void __init ns16550_endboot(struct serial_port *port)
 static int __init ns16550_irq(struct serial_port *port)
 {
     struct ns16550 *uart = port->uart;
-    return ((uart->irq > 0) ? uart->irq : -1);
+    return ((uart->irq.irq > 0) ? uart->irq.irq : -1);
 }
 
+#ifdef CONFIG_ARM
+static const struct dt_irq __init *ns16550_dt_irq(struct serial_port *port)
+{
+    struct ns16550 *uart = port->uart;
+    return &uart->irq;
+}
+#endif
+
 static struct uart_driver __read_mostly ns16550_driver = {
     .init_preirq  = ns16550_init_preirq,
     .init_postirq = ns16550_init_postirq,
@@ -382,7 +427,10 @@ static struct uart_driver __read_mostly ns16550_driver = {
     .tx_ready     = ns16550_tx_ready,
     .putc         = ns16550_putc,
     .getc         = ns16550_getc,
-    .irq          = ns16550_irq
+    .irq          = ns16550_irq,
+#ifdef CONFIG_ARM
+    .dt_irq_get   = ns16550_dt_irq
+#endif
 };
 
 static int __init parse_parity_char(int c)
@@ -403,6 +451,7 @@ static int __init parse_parity_char(int c)
     return 0;
 }
 
+#ifdef CONFIG_X86
 static void __init parse_pci_bdf(const char **conf, unsigned int bdf[3])
 {
     bdf[0] = simple_strtoul(*conf, conf, 16);
@@ -415,6 +464,7 @@ static void __init parse_pci_bdf(const char **conf, unsigned int bdf[3])
     (*conf)++;
     bdf[2] = simple_strtoul(*conf, conf, 16);
 }
+#endif
 
 static int __init check_existence(struct ns16550 *uart)
 {
@@ -428,7 +478,7 @@ static int __init check_existence(struct ns16550 *uart)
         return 1;
 
     pci_serial_early_init(uart);
-    
+
     /*
      * Do a simple existence test first; if we fail this,
      * there's no point trying anything else.
@@ -445,7 +495,7 @@ static int __init check_existence(struct ns16550 *uart)
     scratch3 = ns_read_reg(uart, UART_IER) & 0x0f;
     ns_write_reg(uart, UART_IER, scratch);
     if ( (scratch2 != 0) || (scratch3 != 0x0F) )
-        return 0;
+            return 0;
 
     /*
      * Check to see if a UART is really there.
@@ -456,6 +506,7 @@ static int __init check_existence(struct ns16550 *uart)
     return (status == 0x90);
 }
 
+#ifdef CONFIG_X86
 static int
 pci_uart_config (struct ns16550 *uart, int skip_amt, int bar_idx)
 {
@@ -507,7 +558,7 @@ pci_uart_config (struct ns16550 *uart, int skip_amt, int bar_idx)
                 uart->bar = bar;
                 uart->bar_idx = bar_idx;
                 uart->io_base = bar & ~PCI_BASE_ADDRESS_SPACE_IO;
-                uart->irq = pci_conf_read8(0, b, d, f, PCI_INTERRUPT_PIN) ?
+                uart->irq.irq = pci_conf_read8(0, b, d, f, PCI_INTERRUPT_PIN) ?
                     pci_conf_read8(0, b, d, f, PCI_INTERRUPT_LINE) : 0;
 
                 return 0;
@@ -519,11 +570,12 @@ pci_uart_config (struct ns16550 *uart, int skip_amt, int bar_idx)
         return -1;
 
     uart->io_base = 0x3f8;
-    uart->irq = 0;
+    uart->irq.irq = 0;
     uart->clock_hz  = UART_CLOCK_HZ;
 
     return 0;
 }
+#endif
 
 #define PARSE_ERR(_f, _a...)                 \
     do {                                     \
@@ -534,6 +586,7 @@ pci_uart_config (struct ns16550 *uart, int skip_amt, int bar_idx)
 static void __init ns16550_parse_port_config(
     struct ns16550 *uart, const char *conf)
 {
+#ifdef CONFIG_X86
     int baud;
 
     /* No user-specified configuration? */
@@ -589,7 +642,7 @@ static void __init ns16550_parse_port_config(
     }
 
     if ( *conf == ',' && *++conf != ',' )
-        uart->irq = simple_strtol(conf, &conf, 10);
+        uart->irq.irq = simple_strtol(conf, &conf, 10);
 
     if ( *conf == ',' && *++conf != ',' )
     {
@@ -604,6 +657,8 @@ static void __init ns16550_parse_port_config(
     }
 
  config_parsed:
+#endif
+
     /* Sanity checks. */
     if ( (uart->baud != BAUD_AUTO) &&
          ((uart->baud < 1200) || (uart->baud > 115200)) )
@@ -633,18 +688,80 @@ void __init ns16550_init(int index, struct ns16550_defaults *defaults)
     uart->baud      = (defaults->baud ? :
                        console_has((index == 0) ? "com1" : "com2")
                        ? BAUD_AUTO : 0);
+#ifdef CONFIG_ARM
+    uart->clock_hz = defaults->clock_hz;
+#else
     uart->clock_hz  = UART_CLOCK_HZ;
+#endif
     uart->data_bits = defaults->data_bits;
     uart->parity    = parse_parity_char(defaults->parity);
     uart->stop_bits = defaults->stop_bits;
     uart->irq       = defaults->irq;
     uart->io_base   = defaults->io_base;
+#ifdef CONFIG_ARM
+    uart->io_size   = defaults->io_size;
+#endif
+
     /* Default is no transmit FIFO. */
     uart->fifo_size = 1;
 
     ns16550_parse_port_config(uart, (index == 0) ? opt_com1 : opt_com2);
+
 }
 
+#ifdef CONFIG_ARM
+
+static int __init ns16550_dt_init(struct dt_device_node *dev,
+                                  const void *data)
+{
+    struct ns16550_defaults uart;
+    int res;
+    const __be32 *clkspec;
+
+    uart.baud      = 115200;
+    uart.data_bits = 8;
+    uart.parity    = 'n';
+    uart.stop_bits = 1;
+
+    res = dt_device_get_address(dev, 0, &uart.io_base, &uart.io_size);
+    if (res) {
+        early_printk("ns16550: Unable to retrieve the base"
+                     " address of the UART\n");
+        return res;
+    }
+
+    res = dt_device_get_irq(dev, 0, &uart.irq);
+    if (res) {
+        early_printk("ns16550: Unable to retrieve the IRQ\n");
+        return res;
+    }
+
+    clkspec = dt_get_property(dev, "clock-frequency", NULL);
+    if (clkspec == NULL) {
+        early_printk("ns16550: Unable to retrieve the clock frequency\n");
+        return -EINVAL;
+    }
+    uart.clock_hz = be32_to_cpup(clkspec);
+
+    ns16550_init(0, &uart);
+    dt_device_set_used_by(dev, DOMID_XEN);
+
+    return 0;
+}
+
+static const char const *ns16550_dt_compat[] __initdata =
+{
+    "ti,omap4-uart",
+    NULL
+};
+
+DT_DEVICE_START(ns16550, "NS16550 UART", DEVICE_SERIAL)
+    .compatible = ns16550_dt_compat,
+    .init = ns16550_dt_init,
+DT_DEVICE_END
+
+#endif /* CONFIG_ARM */
+
 /*
  * Local variables:
  * mode: C
diff --git a/xen/include/asm-arm/io.h b/xen/include/asm-arm/io.h
index aea5233..33674bc 100644
--- a/xen/include/asm-arm/io.h
+++ b/xen/include/asm-arm/io.h
@@ -1,6 +1,55 @@
 #ifndef _ASM_IO_H
 #define _ASM_IO_H
 
+static inline void __raw_writeb(u8 val, volatile void __iomem *addr)
+{
+        asm volatile("strb %1, %0"
+                     : "+Qo" (*(volatile u8 __force *)addr)
+                     : "r" (val));
+}
+
+static inline void __raw_writel(u32 val, volatile void __iomem *addr)
+{
+        asm volatile("str %1, %0"
+                     : "+Qo" (*(volatile u32 __force *)addr)
+                     : "r" (val));
+}
+
+static inline u8 __raw_readb(const volatile void __iomem *addr)
+{
+        u8 val;
+        asm volatile("ldrb %1, %0"
+                     : "+Qo" (*(volatile u8 __force *)addr),
+                       "=r" (val));
+        return val;
+}
+
+static inline u32 __raw_readl(const volatile void __iomem *addr)
+{
+        u32 val;
+        asm volatile("ldr %1, %0"
+                     : "+Qo" (*(volatile u32 __force *)addr),
+                       "=r" (val));
+        return val;
+}
+
+#define __iormb()               rmb()
+#define __iowmb()               wmb()
+
+#define readb_relaxed(c) ({ u8  __r = __raw_readb(c); __r; })
+#define readl_relaxed(c) ({ u32 __r = le32_to_cpu((__force __le32) \
+                                        __raw_readl(c)); __r; })
+
+#define writeb_relaxed(v,c)     __raw_writeb(v,c)
+#define writel_relaxed(v,c)     __raw_writel((__force u32) cpu_to_le32(v),c)
+
+#define readb(c)                ({ u8  __v = readb_relaxed(c); __iormb(); __v; })
+#define readl(c)                ({ u32 __v = readl_relaxed(c); __iormb(); __v; })
+
+#define writeb(v,c)             ({ __iowmb(); writeb_relaxed(v,c); })
+#define writel(v,c)             ({ __iowmb(); writel_relaxed(v,c); })
+
+
 #endif
 /*
  * Local variables:
diff --git a/xen/include/xen/serial.h b/xen/include/xen/serial.h
index 9caf776..09ca855 100644
--- a/xen/include/xen/serial.h
+++ b/xen/include/xen/serial.h
@@ -11,6 +11,7 @@
 
 #include <xen/init.h>
 #include <xen/spinlock.h>
+#include <xen/device_tree.h>
 
 struct cpu_user_regs;
 
@@ -151,8 +152,10 @@ struct ns16550_defaults {
     int data_bits; /* default data bits (5, 6, 7 or 8) */
     int parity;    /* default parity (n, o, e, m or s) */
     int stop_bits; /* default stop bits (1 or 2) */
-    int irq;       /* default irq */
-    unsigned long io_base; /* default io_base address */
+    struct dt_irq irq;     /* default irq */
+    u64 io_base;   /* default io_base address */
+    u64 io_size;
+    u32 clock_hz;  /* UART clock rate */
 };
 void ns16550_init(int index, struct ns16550_defaults *defaults);
 void ehci_dbgp_init(void);
-- 
1.8.1.4