[PATCH 1/3] serial: earlycon: Add device-tree support for other IO types
From: Jon Hunter <hidden>
Date: 2016-01-12 10:33:27
Also in:
linux-serial, linux-tegra
Subsystem:
open firmware and flattened device tree, the rest, tty layer and serial drivers · Maintainers:
Rob Herring, Saravana Kannan, Linus Torvalds, Greg Kroah-Hartman, Jiri Slaby
When early console are registered via device-tree, currently it is assumed that the console iotype is UPIO_MEM and the regshift is 0. This is not the case for all devices and so add support for reading the device-tree properties "reg-io-width" and "reg-shift" so that the appropriate iotype and regshift can be specified for a given device. Signed-off-by: Jon Hunter <redacted> --- drivers/of/fdt.c | 26 +++++++++++++++++++++++++- drivers/tty/serial/earlycon.c | 6 ++++-- include/linux/serial_core.h | 3 ++- 3 files changed, 31 insertions(+), 4 deletions(-)
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 655f79db7899..f69406e42631 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c@@ -827,7 +827,9 @@ static int __init early_init_dt_scan_chosen_serial(void) return -ENODEV; while (match->compatible[0]) { + const __be32 *prop; u64 addr; + u8 iotype, regshift; if (fdt_node_check_compatible(fdt, offset, match->compatible)) { match++;
@@ -838,7 +840,29 @@ static int __init early_init_dt_scan_chosen_serial(void) if (addr == OF_BAD_ADDR) return -ENXIO; - of_setup_earlycon(addr, match->data); + prop = fdt_getprop(fdt, offset, "reg-shift", NULL); + regshift = prop ? be32_to_cpup(prop) : 0; + + prop = fdt_getprop(fdt, offset, "reg-io-width", NULL); + if (prop) { + switch (be32_to_cpup(prop)) { + case 1: + iotype = UPIO_MEM; + break; + case 2: + iotype = UPIO_MEM16; + break; + case 4: + iotype = UPIO_MEM32; + break; + default: + return -EINVAL; + } + } else { + iotype = UPIO_MEM; + } + + of_setup_earlycon(addr, iotype, regshift, match->data); return 0; } return -ENODEV;
diff --git a/drivers/tty/serial/earlycon.c b/drivers/tty/serial/earlycon.c
index 3f2423690d01..2fd2f19d7091 100644
--- a/drivers/tty/serial/earlycon.c
+++ b/drivers/tty/serial/earlycon.c@@ -204,17 +204,19 @@ static int __init param_setup_earlycon(char *buf) } early_param("earlycon", param_setup_earlycon); -int __init of_setup_earlycon(unsigned long addr, +int __init of_setup_earlycon(unsigned long addr, unsigned char iotype, + unsigned char regshift, int (*setup)(struct earlycon_device *, const char *)) { int err; struct uart_port *port = &early_console_dev.port; spin_lock_init(&port->lock); - port->iotype = UPIO_MEM; + port->iotype = iotype; port->mapbase = addr; port->uartclk = BASE_BAUD * 16; port->membase = earlycon_map(addr, SZ_4K); + port->regshift = regshift; early_console_dev.con->data = &early_console_dev; err = setup(&early_console_dev, NULL);
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index e03d6ba5e5b4..e0e1c7ef2856 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h@@ -346,7 +346,8 @@ struct earlycon_id { } __aligned(32); extern int setup_earlycon(char *buf); -extern int of_setup_earlycon(unsigned long addr, +extern int of_setup_earlycon(unsigned long addr, unsigned char iotype, + unsigned char regshift, int (*setup)(struct earlycon_device *, const char *)); #define EARLYCON_DECLARE(_name, func) \
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2.1.4