Commit acc902de authored by Andy Shevchenko's avatar Andy Shevchenko Committed by Greg Kroah-Hartman
Browse files

serial: 8250: Move CE4100 quirks to a module under 8250 driver 



There is inconvenient for maintainers and maintainership to have
some quirks under architectural code. Move it to the specific quirk
file like other 8250-compatible drivers do.

Signed-off-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20250627182743.1273326-1-andriy.shevchenko@linux.intel.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 5e40169f

arch/x86/include/asm/ce4100.h

+6 −0
Original line number Diff line number Diff line
@@ -4,4 +4,10 @@ 


int ce4100_pci_init(void);



#ifdef CONFIG_SERIAL_8250

void __init sdv_serial_fixup(void);

#else

static inline void sdv_serial_fixup(void) {};

#endif



#endif

arch/x86/platform/ce4100/ce4100.c

+0 −98
Original line number Diff line number Diff line
@@ -5,19 +5,12 @@ 
 * (C) Copyright 2010 Intel Corporation

 */

#include <linux/init.h>

#include <linux/kernel.h>

#include <linux/irq.h>

#include <linux/reboot.h>

#include <linux/serial_reg.h>

#include <linux/serial_8250.h>



#include <asm/ce4100.h>

#include <asm/prom.h>

#include <asm/setup.h>

#include <asm/i8259.h>

#include <asm/io.h>

#include <asm/io_apic.h>

#include <asm/emergency-restart.h>



/*

 * The CE4100 platform has an internal 8051 Microcontroller which is
@@ -31,97 +24,6 @@ static void ce4100_power_off(void) 
	outb(0x4, 0xcf9);

}



#ifdef CONFIG_SERIAL_8250



static unsigned int mem_serial_in(struct uart_port *p, int offset)

{

	offset = offset << p->regshift;

	return readl(p->membase + offset);

}



/*

 * The UART Tx interrupts are not set under some conditions and therefore serial

 * transmission hangs. This is a silicon issue and has not been root caused. The

 * workaround for this silicon issue checks UART_LSR_THRE bit and UART_LSR_TEMT

 * bit of LSR register in interrupt handler to see whether at least one of these

 * two bits is set, if so then process the transmit request. If this workaround

 * is not applied, then the serial transmission may hang. This workaround is for

 * errata number 9 in Errata - B step.

*/



static u32 ce4100_mem_serial_in(struct uart_port *p, unsigned int offset)

{

	u32 ret, ier, lsr;



	if (offset != UART_IIR)

		return mem_serial_in(p, offset);



	offset <<= p->regshift;



	ret = readl(p->membase + offset);

	if (!(ret & UART_IIR_NO_INT))

		return ret;



	/* see if the TX interrupt should have really set */

	ier = mem_serial_in(p, UART_IER);

	/* see if the UART's XMIT interrupt is enabled */

	if (!(ier & UART_IER_THRI))

		return ret;



	lsr = mem_serial_in(p, UART_LSR);

	/* now check to see if the UART should be generating an interrupt (but isn't) */

	if (lsr & (UART_LSR_THRE | UART_LSR_TEMT))

		ret &= ~UART_IIR_NO_INT;



	return ret;

}



static void ce4100_mem_serial_out(struct uart_port *p, unsigned int offset, u32 value)

{

	offset <<= p->regshift;

	writel(value, p->membase + offset);

}



static void ce4100_serial_fixup(int port, struct uart_port *up,

	u32 *capabilities)

{

#ifdef CONFIG_EARLY_PRINTK

	/*

	 * Over ride the legacy port configuration that comes from

	 * asm/serial.h. Using the ioport driver then switching to the

	 * PCI memmaped driver hangs the IOAPIC

	 */

	if (up->iotype !=  UPIO_MEM32) {

		up->uartclk  = 14745600;

		up->mapbase = 0xdffe0200;

		set_fixmap_nocache(FIX_EARLYCON_MEM_BASE,

				up->mapbase & PAGE_MASK);

		up->membase =

			(void __iomem *)__fix_to_virt(FIX_EARLYCON_MEM_BASE);

		up->membase += up->mapbase & ~PAGE_MASK;

		up->mapbase += port * 0x100;

		up->membase += port * 0x100;

		up->iotype   = UPIO_MEM32;

		up->regshift = 2;

		up->irq = 4;

	}

#endif

	up->iobase = 0;

	up->serial_in = ce4100_mem_serial_in;

	up->serial_out = ce4100_mem_serial_out;



	*capabilities |= (1 << 12);

}



static __init void sdv_serial_fixup(void)

{

	serial8250_set_isa_configurator(ce4100_serial_fixup);

}



#else

static inline void sdv_serial_fixup(void) {};

#endif



static void __init sdv_arch_setup(void)

{

	sdv_serial_fixup();

drivers/tty/serial/8250/8250_ce4100.c

0 → 100644
+98 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-only

/*

 * Intel CE4100  platform specific setup code

 *

 * (C) Copyright 2010 Intel Corporation

 */



#include <linux/init.h>

#include <linux/io.h>

#include <linux/types.h>



#include <asm/ce4100.h>

#include <asm/fixmap.h>

#include <asm/page.h>



#include <linux/serial_reg.h>

#include <linux/serial_8250.h>



static unsigned int mem_serial_in(struct uart_port *p, int offset)

{

	offset = offset << p->regshift;

	return readl(p->membase + offset);

}



/*

 * The UART Tx interrupts are not set under some conditions and therefore serial

 * transmission hangs. This is a silicon issue and has not been root caused. The

 * workaround for this silicon issue checks UART_LSR_THRE bit and UART_LSR_TEMT

 * bit of LSR register in interrupt handler to see whether at least one of these

 * two bits is set, if so then process the transmit request. If this workaround

 * is not applied, then the serial transmission may hang. This workaround is for

 * errata number 9 in Errata - B step.

*/

static u32 ce4100_mem_serial_in(struct uart_port *p, unsigned int offset)

{

	u32 ret, ier, lsr;



	if (offset != UART_IIR)

		return mem_serial_in(p, offset);



	offset <<= p->regshift;



	ret = readl(p->membase + offset);

	if (!(ret & UART_IIR_NO_INT))

		return ret;



	/* see if the TX interrupt should have really set */

	ier = mem_serial_in(p, UART_IER);

	/* see if the UART's XMIT interrupt is enabled */

	if (!(ier & UART_IER_THRI))

		return ret;



	lsr = mem_serial_in(p, UART_LSR);

	/* now check to see if the UART should be generating an interrupt (but isn't) */

	if (lsr & (UART_LSR_THRE | UART_LSR_TEMT))

		ret &= ~UART_IIR_NO_INT;



	return ret;

}



static void ce4100_mem_serial_out(struct uart_port *p, unsigned int offset, u32 value)

{

	offset <<= p->regshift;

	writel(value, p->membase + offset);

}



static void ce4100_serial_fixup(int port, struct uart_port *up, u32 *capabilities)

{

#ifdef CONFIG_EARLY_PRINTK

	/*

	 * Override the legacy port configuration that comes from

	 * asm/serial.h. Using the ioport driver then switching to the

	 * PCI memmaped driver hangs the IOAPIC.

	 */

	if (up->iotype != UPIO_MEM32) {

		up->uartclk = 14745600;

		up->mapbase = 0xdffe0200;

		set_fixmap_nocache(FIX_EARLYCON_MEM_BASE, up->mapbase & PAGE_MASK);

		up->membase = (void __iomem *)__fix_to_virt(FIX_EARLYCON_MEM_BASE);

		up->membase += up->mapbase & ~PAGE_MASK;

		up->mapbase += port * 0x100;

		up->membase += port * 0x100;

		up->iotype = UPIO_MEM32;

		up->regshift = 2;

		up->irq = 4;

	}

#endif

	up->iobase = 0;

	up->serial_in = ce4100_mem_serial_in;

	up->serial_out = ce4100_mem_serial_out;



	*capabilities |= (1 << 12);

}



void __init sdv_serial_fixup(void)

{

	serial8250_set_isa_configurator(ce4100_serial_fixup);

}

drivers/tty/serial/8250/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -24,6 +24,7 @@ obj-$(CONFIG_SERIAL_8250_ASPEED_VUART) += 8250_aspeed_vuart.o 
obj-$(CONFIG_SERIAL_8250_BCM2835AUX)	+= 8250_bcm2835aux.o

obj-$(CONFIG_SERIAL_8250_BCM7271)	+= 8250_bcm7271.o

obj-$(CONFIG_SERIAL_8250_BOCA)		+= 8250_boca.o

obj-$(CONFIG_X86_INTEL_CE)		+= 8250_ce4100.o

obj-$(CONFIG_SERIAL_8250_DFL)		+= 8250_dfl.o

obj-$(CONFIG_SERIAL_8250_DW)		+= 8250_dw.o

obj-$(CONFIG_SERIAL_8250_EM)		+= 8250_em.o