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Commit c11e3b48 authored by Paul Burton's avatar Paul Burton Committed by Ralf Baechle
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MIPS: SEAD3: Probe UARTs using DT 



Probe the UARTs on SEAD3 boards using device tree rather than platform
code, in order to reduce the amount of the latter. This requires that
CONFIG_SERIAL_OF_PLATFORM be enabled, so enable it in sead3_defconfig.
The SEAD3 DT shim code is extended to read bootloader environment
variables to determine the appropriate UART & mode for kernel console
output & set the stdout-path property of the chosen node accordingly.

In contrast to the old platform code, which appears to have only ever
set "console=ttyS0,38400n8r" with the code in console_config never
having an effect, this will honor the "yamontty" environment variable to
select between the 2 UARTs on the board and then check the "modetty0" or
"modetty1" variable as appropriate to determine the UART configuration.

Signed-off-by: default avatarPaul Burton <paul.burton@imgtec.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: linux-mips@linux-mips.org
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14048/


Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
parent b6d5e47e

arch/mips/boot/dts/mti/sead3.dts

+37 −0
Original line number Diff line number Diff line
@@ -12,6 +12,15 @@ 
	compatible = "mti,sead-3";

	interrupt-parent = <&gic>;



	chosen {

		stdout-path = "uart1:115200";

	};



	aliases {

		uart0 = &uart0;

		uart1 = &uart1;

	};



	cpus {

		cpu@0 {

			compatible = "mti,mips14KEc", "mti,mips14Kc";
@@ -50,4 +59,32 @@ 
			interrupts = <GIC_LOCAL 1 IRQ_TYPE_NONE>;

		};

	};



	/* UART connected to FTDI & miniUSB socket */

	uart0: uart@1f000900 {

		compatible = "ns16550a";

		reg = <0x1f000900 0x20>;

		reg-io-width = <4>;

		reg-shift = <2>;



		clock-frequency = <14745600>;



		interrupts = <3>; /* GIC 3 or CPU 4 */



		no-loopback-test;

	};



	/* UART connected to RS232 socket */

	uart1: uart@1f000800 {

		compatible = "ns16550a";

		reg = <0x1f000800 0x20>;

		reg-io-width = <4>;

		reg-shift = <2>;



		clock-frequency = <14745600>;



		interrupts = <2>; /* GIC 2 or CPU 4 */



		no-loopback-test;

	};

};

arch/mips/configs/sead3_defconfig

+2 −0
Original line number Diff line number Diff line
@@ -39,6 +39,7 @@ CONFIG_MTD_CFI_INTELEXT=y 
CONFIG_MTD_PHYSMAP=y

CONFIG_MTD_UBI=y

CONFIG_MTD_UBI_GLUEBI=y

CONFIG_OF=y

CONFIG_BLK_DEV_LOOP=y

CONFIG_BLK_DEV_CRYPTOLOOP=m

CONFIG_SCSI=y
@@ -70,6 +71,7 @@ CONFIG_SERIAL_8250=y 
CONFIG_SERIAL_8250_CONSOLE=y

CONFIG_SERIAL_8250_NR_UARTS=2

CONFIG_SERIAL_8250_RUNTIME_UARTS=2

CONFIG_SERIAL_OF_PLATFORM=y

# CONFIG_HW_RANDOM is not set

CONFIG_I2C=y

# CONFIG_I2C_COMPAT is not set

arch/mips/include/asm/mips-boards/sead3int.h

+0 −4
Original line number Diff line number Diff line
@@ -14,14 +14,10 @@ 


/* CPU interrupt offsets */

#define CPU_INT_EHCI		2

#define CPU_INT_UART0		4

#define CPU_INT_UART1		4

#define CPU_INT_NET		6



/* GIC interrupt offsets */

#define GIC_INT_NET		GIC_SHARED_TO_HWIRQ(0)

#define GIC_INT_UART1		GIC_SHARED_TO_HWIRQ(2)

#define GIC_INT_UART0		GIC_SHARED_TO_HWIRQ(3)

#define GIC_INT_EHCI		GIC_SHARED_TO_HWIRQ(5)



#endif /* !(_MIPS_SEAD3INT_H) */

arch/mips/mti-sead3/sead3-dtshim.c

+104 −1
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 
#include <linux/libfdt.h>

#include <linux/printk.h>



#include <asm/fw/fw.h>

#include <asm/io.h>



#define SEAD_CONFIG			CKSEG1ADDR(0x1b100110)
@@ -23,7 +24,8 @@ static unsigned char fdt_buf[16 << 10] __initdata; 


static int remove_gic(void *fdt)

{

	int gic_off, cpu_off, err;

	const unsigned int cpu_uart_int = 4;

	int gic_off, cpu_off, uart_off, err;

	uint32_t cfg, cpu_phandle;



	/* leave the GIC node intact if a GIC is present */
@@ -62,6 +64,103 @@ static int remove_gic(void *fdt) 
		return err;

	}



	uart_off = fdt_node_offset_by_compatible(fdt, -1, "ns16550a");

	while (uart_off >= 0) {

		err = fdt_setprop_u32(fdt, uart_off, "interrupts",

				      cpu_uart_int);

		if (err) {

			pr_err("unable to set UART interrupts property: %d\n",

			       err);

			return err;

		}



		uart_off = fdt_node_offset_by_compatible(fdt, uart_off,

							 "ns16550a");

	}

	if (uart_off != -FDT_ERR_NOTFOUND) {

		pr_err("error searching for UART DT node: %d\n", uart_off);

		return uart_off;

	}



	return 0;

}



static int serial_config(void *fdt)

{

	const char *yamontty, *mode_var;

	char mode_var_name[9], path[18], parity;

	unsigned int uart, baud, stop_bits;

	bool hw_flow;

	int chosen_off, err;



	yamontty = fw_getenv("yamontty");

	if (!yamontty || !strcmp(yamontty, "tty0")) {

		uart = 0;

	} else if (!strcmp(yamontty, "tty1")) {

		uart = 1;

	} else {

		pr_warn("yamontty environment variable '%s' invalid\n",

			yamontty);

		uart = 0;

	}



	baud = stop_bits = 0;

	parity = 0;

	hw_flow = false;



	snprintf(mode_var_name, sizeof(mode_var_name), "modetty%u", uart);

	mode_var = fw_getenv(mode_var_name);

	if (mode_var) {

		while (mode_var[0] >= '0' && mode_var[0] <= '9') {

			baud *= 10;

			baud += mode_var[0] - '0';

			mode_var++;

		}

		if (mode_var[0] == ',')

			mode_var++;

		if (mode_var[0])

			parity = mode_var[0];

		if (mode_var[0] == ',')

			mode_var++;

		if (mode_var[0])

			stop_bits = mode_var[0] - '0';

		if (mode_var[0] == ',')

			mode_var++;

		if (!strcmp(mode_var, "hw"))

			hw_flow = true;

	}



	if (!baud)

		baud = 38400;



	if (parity != 'e' && parity != 'n' && parity != 'o')

		parity = 'n';



	if (stop_bits != 7 && stop_bits != 8)

		stop_bits = 8;



	WARN_ON(snprintf(path, sizeof(path), "uart%u:%u%c%u%s",

			 uart, baud, parity, stop_bits,

			 hw_flow ? "r" : "") >= sizeof(path));



	/* find or add chosen node */

	chosen_off = fdt_path_offset(fdt, "/chosen");

	if (chosen_off == -FDT_ERR_NOTFOUND)

		chosen_off = fdt_path_offset(fdt, "/chosen@0");

	if (chosen_off == -FDT_ERR_NOTFOUND)

		chosen_off = fdt_add_subnode(fdt, 0, "chosen");

	if (chosen_off < 0) {

		pr_err("Unable to find or add DT chosen node: %d\n",

		       chosen_off);

		return chosen_off;

	}



	err = fdt_setprop_string(fdt, chosen_off, "stdout-path", path);

	if (err) {

		pr_err("Unable to set stdout-path property: %d\n", err);

		return err;

	}



	return 0;

}
@@ -84,6 +183,10 @@ void __init *sead3_dt_shim(void *fdt) 
	if (err)

		panic("Unable to patch FDT: %d", err);



	err = serial_config(fdt_buf);

	if (err)

		panic("Unable to patch FDT: %d", err);



	err = fdt_pack(fdt_buf);

	if (err)

		panic("Unable to pack FDT: %d\n", err);

arch/mips/mti-sead3/sead3-init.c

+0 −46
Original line number Diff line number Diff line
@@ -17,47 +17,6 @@ 
extern char except_vec_nmi;

extern char except_vec_ejtag_debug;



#ifdef CONFIG_SERIAL_8250_CONSOLE

static void __init console_config(void)

{

	char console_string[40];

	int baud = 0;

	char parity = '\0', bits = '\0', flow = '\0';

	char *s;



	if ((strstr(fw_getcmdline(), "console=")) == NULL) {

		s = fw_getenv("modetty0");

		if (s) {

			while (*s >= '0' && *s <= '9')

				baud = baud*10 + *s++ - '0';

			if (*s == ',')

				s++;

			if (*s)

				parity = *s++;

			if (*s == ',')

				s++;

			if (*s)

				bits = *s++;

			if (*s == ',')

				s++;

			if (*s == 'h')

				flow = 'r';

		}

		if (baud == 0)

			baud = 38400;

		if (parity != 'n' && parity != 'o' && parity != 'e')

			parity = 'n';

		if (bits != '7' && bits != '8')

			bits = '8';

		if (flow == '\0')

			flow = 'r';

		sprintf(console_string, " console=ttyS0,%d%c%c%c", baud,

			parity, bits, flow);

		strcat(fw_getcmdline(), console_string);

	}

}

#endif



static void __init mips_nmi_setup(void)

{

	void *base;
@@ -140,11 +99,6 @@ void __init prom_init(void) 
	else if ((strstr(fw_getcmdline(), "console=ttyS1")) != NULL)

		fw_init_early_console(1);

#endif

#ifdef CONFIG_SERIAL_8250_CONSOLE

	if ((strstr(fw_getcmdline(), "console=")) == NULL)

		strcat(fw_getcmdline(), " console=ttyS0,38400n8r");

	console_config();

#endif

}



void __init prom_free_prom_memory(void)