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[Xen-devel] [PATCH V3 29/41] xen/arm: Use device tree API in pl011 UART driver



Allow UART driver to retrieve all its information in the device tree.
It's possible to choose the pl011 driver via the Xen command line.

Signed-off-by: Julien Grall <julien.grall@xxxxxxxxxx>

Changes in v3:
    - Remove the usage of serial_arm_defaults
    - Get the base address from the DT and map it with ioremap_attr
    - Allow only 1 PL011 assigned to SERHND_DTUART
    - Replace DT_USED_BY_XEN by DOMID_XEN

Changes in v2:
    - Rework TODO
    - Use the new function setup_dt_irq
---
 xen/arch/arm/gic.c       |    4 ---
 xen/arch/arm/setup.c     |    4 ---
 xen/drivers/char/pl011.c |   84 ++++++++++++++++++++++++++++++++++++----------
 xen/include/xen/serial.h |    1 -
 4 files changed, 67 insertions(+), 26 deletions(-)

diff --git a/xen/arch/arm/gic.c b/xen/arch/arm/gic.c
index 95eb6c6..a46516a 100644
--- a/xen/arch/arm/gic.c
+++ b/xen/arch/arm/gic.c
@@ -505,10 +505,6 @@ void gic_route_spis(void)
     int seridx;
     const struct dt_irq *irq;
 
-    /* XXX should get these from DT */
-    /* UART */
-    gic_route_irq(37, 0, 1u << smp_processor_id(), 0xa0);
-
     for ( seridx = 0; seridx <= SERHND_IDX; seridx++ )
     {
         if ( (irq = serial_dt_irq(seridx)) == NULL )
diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c
index 2e331d3..e5f4459 100644
--- a/xen/arch/arm/setup.c
+++ b/xen/arch/arm/setup.c
@@ -433,10 +433,6 @@ void __init start_xen(unsigned long boot_phys_offset,
     dt_unflatten_host_device_tree();
     dt_irq_xlate = gic_irq_xlate;
 
-#ifdef EARLY_UART_ADDRESS
-    /* TODO Need to get device tree or command line for UART address */
-    pl011_init(0, FIXMAP_ADDR(FIXMAP_CONSOLE));
-#endif
     dt_uart_init();
     console_init_preirq();
 
diff --git a/xen/drivers/char/pl011.c b/xen/drivers/char/pl011.c
index 8efd08e..9a4e3b9 100644
--- a/xen/drivers/char/pl011.c
+++ b/xen/drivers/char/pl011.c
@@ -22,9 +22,16 @@
 #include <xen/serial.h>
 #include <xen/init.h>
 #include <xen/irq.h>
+#include <asm/early_printk.h>
+#include <xen/device_tree.h>
+#include <xen/errno.h>
+#include <asm/device.h>
+#include <xen/mm.h>
+#include <xen/vmap.h>
 
 static struct pl011 {
-    unsigned int baud, clock_hz, data_bits, parity, stop_bits, irq;
+    unsigned int baud, clock_hz, data_bits, parity, stop_bits;
+    struct dt_irq irq;
     volatile uint32_t *regs;
     /* UART with IRQ line: interrupt-driven I/O. */
     struct irqaction irqaction;
@@ -32,7 +39,7 @@ static struct pl011 {
     /* struct timer timer; */
     /* unsigned int timeout_ms; */
     /* bool_t probing, intr_works; */
-} pl011_com[2] = {{0}};
+} pl011_com = {0};
 
 /* PL011 register addresses */
 #define DR     (0x00/4)
@@ -163,13 +170,13 @@ static void __init pl011_init_postirq(struct serial_port 
*port)
     struct pl011 *uart = port->uart;
     int rc;
 
-    if ( uart->irq > 0 )
+    if ( uart->irq.irq > 0 )
     {
         uart->irqaction.handler = pl011_interrupt;
         uart->irqaction.name    = "pl011";
         uart->irqaction.dev_id  = port;
-        if ( (rc = setup_irq(uart->irq, &uart->irqaction)) != 0 )
-            printk("ERROR: Failed to allocate pl011 IRQ %d\n", uart->irq);
+        if ( (rc = setup_dt_irq(&uart->irq, &uart->irqaction)) != 0 )
+            printk("ERROR: Failed to allocate pl011 IRQ %d\n", uart->irq.irq);
     }
 
     /* Clear pending error interrupts */
@@ -215,7 +222,14 @@ static int pl011_getc(struct serial_port *port, char *pc)
 static int __init pl011_irq(struct serial_port *port)
 {
     struct pl011 *uart = port->uart;
-    return ((uart->irq > 0) ? uart->irq : -1);
+    return ((uart->irq.irq > 0) ? uart->irq.irq : -1);
+}
+
+static const struct dt_irq __init *pl011_dt_irq(struct serial_port *port)
+{
+    struct pl011 *uart = port->uart;
+
+    return &uart->irq;
 }
 
 static struct uart_driver __read_mostly pl011_driver = {
@@ -227,32 +241,68 @@ static struct uart_driver __read_mostly pl011_driver = {
     .tx_ready     = pl011_tx_ready,
     .putc         = pl011_putc,
     .getc         = pl011_getc,
-    .irq          = pl011_irq
+    .irq          = pl011_irq,
+    .dt_irq_get   = pl011_dt_irq,
 };
 
-/* TODO: Parse UART config from device-tree or command-line */
-
-void __init pl011_init(int index, unsigned long register_base_address)
+/* TODO: Parse UART config from the command line */
+static int __init pl011_uart_init(struct dt_device_node *dev,
+                                  const void *data)
 {
     struct pl011 *uart;
+    int res;
+    u64 addr, size;
 
-    if ( (index < 0) || (index > 1) )
-        return;
-
-    uart = &pl011_com[index];
+    uart = &pl011_com;
 
     uart->clock_hz  = 0x16e3600;
     uart->baud      = 38400;
     uart->data_bits = 8;
     uart->parity    = PARITY_NONE;
     uart->stop_bits = 1;
-    uart->irq       = 37; /* TODO Need to find this from devicetree */
-    uart->regs      = (uint32_t *) register_base_address;
+
+    res = dt_device_get_address(dev, 0, &addr, &size);
+    if ( res )
+    {
+        early_printk("pl011: Unable to retrieve the base"
+                     " address of the UART\n");
+        return res;
+    }
+
+    uart->regs = ioremap_attr(addr, size, PAGE_HYPERVISOR_NOCACHE);
+    if ( !uart->regs )
+    {
+        early_printk("pl011: Unable to map the UART memory\n");
+
+        return -ENOMEM;
+    }
+
+    res = dt_device_get_irq(dev, 0, &uart->irq);
+    if ( res )
+    {
+        early_printk("pl011: Unable to retrieve the IRQ\n");
+        return res;
+    }
 
     /* Register with generic serial driver. */
-    serial_register_uart(uart - pl011_com, &pl011_driver, uart);
+    serial_register_uart(SERHND_DTUART, &pl011_driver, uart);
+
+    dt_device_set_used_by(dev, DOMID_XEN);
+
+    return 0;
 }
 
+static const char const *pl011_dt_compat[] __initdata =
+{
+    "arm,pl011",
+    NULL
+};
+
+DT_DEVICE_START(pl011, "PL011 UART", DEVICE_SERIAL)
+        .compatible = pl011_dt_compat,
+        .init = pl011_uart_init,
+DT_DEVICE_END
+
 /*
  * Local variables:
  * mode: C
diff --git a/xen/include/xen/serial.h b/xen/include/xen/serial.h
index 8af3bc4..9caf776 100644
--- a/xen/include/xen/serial.h
+++ b/xen/include/xen/serial.h
@@ -157,7 +157,6 @@ struct ns16550_defaults {
 void ns16550_init(int index, struct ns16550_defaults *defaults);
 void ehci_dbgp_init(void);
 
-void pl011_init(int index, unsigned long register_base_address);
 void __init dt_uart_init(void);
 
 struct physdev_dbgp_op;
-- 
1.7.10.4


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