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linux-next/arch/arc/plat-arcfpga/platform.c
Vineet Gupta e87a850b9c ARC: [arcfpga] Early ARC UART to be only activated by cmdline
Earlier CONFIG_SERIAL_ARC_CONSOLE would unconditionally enable the
legacy ARC UART based early console even if platform lacked that UART
(e.g. nSIM OSCI platform).

So a multi-platform image containing the 2 UART drivers won't work.

Fix that by probing the driver only if "earlyprintk=ttyARC0" is present
in cmdline.

Reported-by: Chuck Jordan <cjordan@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2014-06-03 14:20:09 +05:30

185 lines
4.6 KiB
C

/*
* ARC FPGA Platform support code
*
* Copyright (C) 2012 Synopsys, Inc. (www.synopsys.com)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/types.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/console.h>
#include <linux/of_platform.h>
#include <asm/setup.h>
#include <asm/clk.h>
#include <asm/mach_desc.h>
#include <plat/memmap.h>
#include <plat/smp.h>
#include <plat/irq.h>
/*----------------------- Platform Devices -----------------------------*/
#if IS_ENABLED(CONFIG_SERIAL_ARC)
static unsigned long arc_uart_info[] = {
0, /* uart->is_emulated (runtime @running_on_hw) */
0, /* uart->port.uartclk */
0, /* uart->baud */
0
};
#if defined(CONFIG_SERIAL_ARC_CONSOLE)
/*
* static platform data - but only for early serial
* TBD: derive this from a special DT node
*/
static struct resource arc_uart0_res[] = {
{
.start = UART0_BASE,
.end = UART0_BASE + 0xFF,
.flags = IORESOURCE_MEM,
},
{
.start = UART0_IRQ,
.end = UART0_IRQ,
.flags = IORESOURCE_IRQ,
},
};
static struct platform_device arc_uart0_dev = {
.name = "arc-uart",
.id = 0,
.num_resources = ARRAY_SIZE(arc_uart0_res),
.resource = arc_uart0_res,
.dev = {
.platform_data = &arc_uart_info,
},
};
static struct platform_device *fpga_early_devs[] __initdata = {
&arc_uart0_dev,
};
#endif /* CONFIG_SERIAL_ARC_CONSOLE */
static void arc_fpga_serial_init(void)
{
/* To let driver workaround ISS bug: baudh Reg can't be set to 0 */
arc_uart_info[0] = !running_on_hw;
arc_uart_info[1] = arc_get_core_freq();
arc_uart_info[2] = CONFIG_ARC_SERIAL_BAUD;
#if defined(CONFIG_SERIAL_ARC_CONSOLE)
early_platform_add_devices(fpga_early_devs,
ARRAY_SIZE(fpga_early_devs));
/*
* ARC console driver registers (build time) as an early platform driver
* of class "earlyprintk". However it needs explicit cmdline toggle
* "earlyprintk=ttyARC0" to be successfuly runtime registered.
* Otherwise the early probe below fails to find the driver
*/
early_platform_driver_probe("earlyprintk", 1, 0);
/*
* This is to make sure that arc uart would be preferred console
* despite one/more of following:
* -command line lacked "console=ttyARC0" or
* -CONFIG_VT_CONSOLE was enabled (for no reason whatsoever)
* Note that this needs to be done after above early console is reg,
* otherwise the early console never gets a chance to run.
*/
add_preferred_console("ttyARC", 0, "115200");
#endif /* CONFIG_SERIAL_ARC_CONSOLE */
}
#else /* !IS_ENABLED(CONFIG_SERIAL_ARC) */
static void arc_fpga_serial_init(void)
{
}
#endif
static void __init plat_fpga_early_init(void)
{
pr_info("[plat-arcfpga]: registering early dev resources\n");
arc_fpga_serial_init();
#ifdef CONFIG_ISS_SMP_EXTN
iss_model_init_early_smp();
#endif
}
static struct of_dev_auxdata plat_auxdata_lookup[] __initdata = {
#if IS_ENABLED(CONFIG_SERIAL_ARC)
OF_DEV_AUXDATA("snps,arc-uart", UART0_BASE, "arc-uart", arc_uart_info),
#endif
{}
};
static void __init plat_fpga_populate_dev(void)
{
pr_info("[plat-arcfpga]: registering device resources\n");
/*
* Traverses flattened DeviceTree - registering platform devices
* complete with their resources
*/
of_platform_populate(NULL, of_default_bus_match_table,
plat_auxdata_lookup, NULL);
}
/*----------------------- Machine Descriptions ------------------------------
*
* Machine description is simply a set of platform/board specific callbacks
* This is not directly related to DeviceTree based dynamic device creation,
* however as part of early device tree scan, we also select the right
* callback set, by matching the DT compatible name.
*/
static const char *aa4_compat[] __initconst = {
"snps,arc-angel4",
NULL,
};
MACHINE_START(ANGEL4, "angel4")
.dt_compat = aa4_compat,
.init_early = plat_fpga_early_init,
.init_machine = plat_fpga_populate_dev,
.init_irq = plat_fpga_init_IRQ,
#ifdef CONFIG_ISS_SMP_EXTN
.init_smp = iss_model_init_smp,
#endif
MACHINE_END
static const char *ml509_compat[] __initconst = {
"snps,arc-ml509",
NULL,
};
MACHINE_START(ML509, "ml509")
.dt_compat = ml509_compat,
.init_early = plat_fpga_early_init,
.init_machine = plat_fpga_populate_dev,
.init_irq = plat_fpga_init_IRQ,
#ifdef CONFIG_SMP
.init_smp = iss_model_init_smp,
#endif
MACHINE_END
static const char *nsimosci_compat[] __initconst = {
"snps,nsimosci",
NULL,
};
MACHINE_START(NSIMOSCI, "nsimosci")
.dt_compat = nsimosci_compat,
.init_early = NULL,
.init_machine = plat_fpga_populate_dev,
.init_irq = NULL,
MACHINE_END