nds32: Remove the architecture

The nds32 architecture, also known as AndeStar V3, is a custom 32-bit
RISC target designed by Andes Technologies. Support was added to the
kernel in 2016 as the replacement RISC-V based V5 processors were
already announced, and maintained by (current or former) Andes
employees.

As explained by Alan Kao, new customers are now all using RISC-V,
and all known nds32 users are already on longterm stable kernels
provided by Andes, with no development work going into mainline
support any more.

While the port is still in a reasonably good shape, it only gets
worse over time without active maintainers, so it seems best
to remove it before it becomes unusable. As always, if it turns
out that there are mainline users after all, and they volunteer
to maintain the port in the future, the removal can be reverted.

Link: https://lore.kernel.org/linux-mm/YhdWNLUhk+x9RAzU@yamatobi.andestech.com/
Link: https://lore.kernel.org/lkml/20220302065213.82702-1-alankao@andestech.com/
Link: https://www.andestech.com/en/products-solutions/andestar-architecture/
Signed-off-by: Alan Kao <alankao@andestech.com>
[arnd: rewrite changelog to provide more background]
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

3 files changed, 0 insertions, 276 deletions

diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index cfb8ea0df3b1..ae95d06a4a8f 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -617,15 +617,6 @@ config CLKSRC_ST_LPC
 	  Enable this option to use the Low Power controller timer
 	  as clocksource.
 
-config ATCPIT100_TIMER
-	bool "ATCPIT100 timer driver"
-	depends on NDS32 || COMPILE_TEST
-	depends on HAS_IOMEM
-	select TIMER_OF
-	default NDS32
-	help
-	  This option enables support for the Andestech ATCPIT100 timers.
-
 config RISCV_TIMER
 	bool "Timer for the RISC-V platform" if COMPILE_TEST
 	depends on GENERIC_SCHED_CLOCK && RISCV && RISCV_SBI
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index fa5f624eadb6..9c85ee2bb373 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -81,7 +81,6 @@ obj-$(CONFIG_INGENIC_SYSOST)	+= ingenic-sysost.o
 obj-$(CONFIG_INGENIC_TIMER)		+= ingenic-timer.o
 obj-$(CONFIG_CLKSRC_ST_LPC)		+= clksrc_st_lpc.o
 obj-$(CONFIG_X86_NUMACHIP)		+= numachip.o
-obj-$(CONFIG_ATCPIT100_TIMER)		+= timer-atcpit100.o
 obj-$(CONFIG_RISCV_TIMER)		+= timer-riscv.o
 obj-$(CONFIG_CLINT_TIMER)		+= timer-clint.o
 obj-$(CONFIG_CSKY_MP_TIMER)		+= timer-mp-csky.o
diff --git a/drivers/clocksource/timer-atcpit100.c b/drivers/clocksource/timer-atcpit100.c
deleted file mode 100644
index b4bd2f5b801d..000000000000
--- a/drivers/clocksource/timer-atcpit100.c
+++ /dev/null
@@ -1,266 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-// Copyright (C) 2005-2017 Andes Technology Corporation
-/*
- *  Andestech ATCPIT100 Timer Device Driver Implementation
- * Rick Chen, Andes Technology Corporation <rick@andestech.com>
- *
- */
-
-#include <linux/irq.h>
-#include <linux/clocksource.h>
-#include <linux/clockchips.h>
-#include <linux/interrupt.h>
-#include <linux/ioport.h>
-#include <linux/cpufreq.h>
-#include <linux/sched.h>
-#include <linux/sched_clock.h>
-#include <linux/of_address.h>
-#include <linux/of_irq.h>
-#include <linux/of_platform.h>
-#include "timer-of.h"
-#ifdef CONFIG_NDS32
-#include <asm/vdso_timer_info.h>
-#endif
-
-/*
- * Definition of register offsets
- */
-
-/* ID and Revision Register */
-#define ID_REV		0x0
-
-/* Configuration Register */
-#define CFG		0x10
-
-/* Interrupt Enable Register */
-#define INT_EN		0x14
-#define CH_INT_EN(c, i)	((1<<i)<<(4*c))
-#define CH0INT0EN	0x01
-
-/* Interrupt Status Register */
-#define INT_STA		0x18
-#define CH0INT0		0x01
-
-/* Channel Enable Register */
-#define CH_EN		0x1C
-#define CH0TMR0EN	0x1
-#define CH1TMR0EN	0x10
-
-/* Channel 0 , 1 Control Register */
-#define CH0_CTL		(0x20)
-#define CH1_CTL		(0x20 + 0x10)
-
-/* Channel clock source , bit 3 , 0:External clock , 1:APB clock */
-#define APB_CLK		BIT(3)
-
-/* Channel mode , bit 0~2 */
-#define TMR_32		0x1
-#define TMR_16		0x2
-#define TMR_8		0x3
-
-/* Channel 0 , 1 Reload Register */
-#define CH0_REL		(0x24)
-#define CH1_REL		(0x24 + 0x10)
-
-/* Channel 0 , 1 Counter Register */
-#define CH0_CNT		(0x28)
-#define CH1_CNT		(0x28 + 0x10)
-
-#define TIMER_SYNC_TICKS	3
-
-static void atcpit100_ch1_tmr0_en(void __iomem *base)
-{
-	writel(~0, base + CH1_REL);
-	writel(APB_CLK|TMR_32, base + CH1_CTL);
-}
-
-static void atcpit100_ch0_tmr0_en(void __iomem *base)
-{
-	writel(APB_CLK|TMR_32, base + CH0_CTL);
-}
-
-static void atcpit100_clkevt_time_setup(void __iomem *base, unsigned long delay)
-{
-	writel(delay, base + CH0_CNT);
-	writel(delay, base + CH0_REL);
-}
-
-static void atcpit100_timer_clear_interrupt(void __iomem *base)
-{
-	u32 val;
-
-	val = readl(base + INT_STA);
-	writel(val | CH0INT0, base + INT_STA);
-}
-
-static void atcpit100_clocksource_start(void __iomem *base)
-{
-	u32 val;
-
-	val = readl(base + CH_EN);
-	writel(val | CH1TMR0EN, base + CH_EN);
-}
-
-static void atcpit100_clkevt_time_start(void __iomem *base)
-{
-	u32 val;
-
-	val = readl(base + CH_EN);
-	writel(val | CH0TMR0EN, base + CH_EN);
-}
-
-static void atcpit100_clkevt_time_stop(void __iomem *base)
-{
-	u32 val;
-
-	atcpit100_timer_clear_interrupt(base);
-	val = readl(base + CH_EN);
-	writel(val & ~CH0TMR0EN, base + CH_EN);
-}
-
-static int atcpit100_clkevt_next_event(unsigned long evt,
-	struct clock_event_device *clkevt)
-{
-	u32 val;
-	struct timer_of *to = to_timer_of(clkevt);
-
-	val = readl(timer_of_base(to) + CH_EN);
-	writel(val & ~CH0TMR0EN, timer_of_base(to) + CH_EN);
-	writel(evt, timer_of_base(to) + CH0_REL);
-	writel(val | CH0TMR0EN, timer_of_base(to) + CH_EN);
-
-	return 0;
-}
-
-static int atcpit100_clkevt_set_periodic(struct clock_event_device *evt)
-{
-	struct timer_of *to = to_timer_of(evt);
-
-	atcpit100_clkevt_time_setup(timer_of_base(to), timer_of_period(to));
-	atcpit100_clkevt_time_start(timer_of_base(to));
-
-	return 0;
-}
-static int atcpit100_clkevt_shutdown(struct clock_event_device *evt)
-{
-	struct timer_of *to = to_timer_of(evt);
-
-	atcpit100_clkevt_time_stop(timer_of_base(to));
-
-	return 0;
-}
-static int atcpit100_clkevt_set_oneshot(struct clock_event_device *evt)
-{
-	struct timer_of *to = to_timer_of(evt);
-	u32 val;
-
-	writel(~0x0, timer_of_base(to) + CH0_REL);
-	val = readl(timer_of_base(to) + CH_EN);
-	writel(val | CH0TMR0EN, timer_of_base(to) + CH_EN);
-
-	return 0;
-}
-
-static irqreturn_t atcpit100_timer_interrupt(int irq, void *dev_id)
-{
-	struct clock_event_device *evt = (struct clock_event_device *)dev_id;
-	struct timer_of *to = to_timer_of(evt);
-
-	atcpit100_timer_clear_interrupt(timer_of_base(to));
-
-	evt->event_handler(evt);
-
-	return IRQ_HANDLED;
-}
-
-static struct timer_of to = {
-	.flags = TIMER_OF_IRQ | TIMER_OF_CLOCK | TIMER_OF_BASE,
-
-	.clkevt = {
-		.name = "atcpit100_tick",
-		.rating = 300,
-		.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
-		.set_state_shutdown = atcpit100_clkevt_shutdown,
-		.set_state_periodic = atcpit100_clkevt_set_periodic,
-		.set_state_oneshot = atcpit100_clkevt_set_oneshot,
-		.tick_resume = atcpit100_clkevt_shutdown,
-		.set_next_event = atcpit100_clkevt_next_event,
-		.cpumask = cpu_possible_mask,
-	},
-
-	.of_irq = {
-		.handler = atcpit100_timer_interrupt,
-		.flags = IRQF_TIMER | IRQF_IRQPOLL,
-	},
-
-	/*
-	 * FIXME: we currently only support clocking using PCLK
-	 * and using EXTCLK is not supported in the driver.
-	 */
-	.of_clk = {
-		.name = "PCLK",
-	}
-};
-
-static u64 notrace atcpit100_timer_sched_read(void)
-{
-	return ~readl(timer_of_base(&to) + CH1_CNT);
-}
-
-#ifdef CONFIG_NDS32
-static void fill_vdso_need_info(struct device_node *node)
-{
-	struct resource timer_res;
-	of_address_to_resource(node, 0, &timer_res);
-	timer_info.mapping_base = (unsigned long)timer_res.start;
-	timer_info.cycle_count_down = true;
-	timer_info.cycle_count_reg_offset = CH1_CNT;
-}
-#endif
-
-static int __init atcpit100_timer_init(struct device_node *node)
-{
-	int ret;
-	u32 val;
-	void __iomem *base;
-
-	ret = timer_of_init(node, &to);
-	if (ret)
-		return ret;
-
-	base = timer_of_base(&to);
-
-	sched_clock_register(atcpit100_timer_sched_read, 32,
-		timer_of_rate(&to));
-
-	ret = clocksource_mmio_init(base + CH1_CNT,
-		node->name, timer_of_rate(&to), 300, 32,
-		clocksource_mmio_readl_down);
-
-	if (ret) {
-		pr_err("Failed to register clocksource\n");
-		return ret;
-	}
-
-	/* clear channel 0 timer0 interrupt */
-	atcpit100_timer_clear_interrupt(base);
-
-	clockevents_config_and_register(&to.clkevt, timer_of_rate(&to),
-					TIMER_SYNC_TICKS, 0xffffffff);
-	atcpit100_ch0_tmr0_en(base);
-	atcpit100_ch1_tmr0_en(base);
-	atcpit100_clocksource_start(base);
-	atcpit100_clkevt_time_start(base);
-
-	/* Enable channel 0 timer0 interrupt */
-	val = readl(base + INT_EN);
-	writel(val | CH0INT0EN, base + INT_EN);
-
-#ifdef CONFIG_NDS32
-	fill_vdso_need_info(node);
-#endif
-
-	return ret;
-}
-
-TIMER_OF_DECLARE(atcpit100, "andestech,atcpit100", atcpit100_timer_init);