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There is a distinct version of the Ux500 U8420 variant with "sysclk", as can be seen from the vendor code that didn't make it upstream, this firmware lacks the ULPPLL (ultra-low power phase locked loop) which in effect means that the timer clock is instead wired to the 32768 Hz always-on clock. This has some repercussions when enabling the timer clock as the code as it stands will disable the timer clock on these platforms (lacking the so-called "doze mode") and obtaining the wrong rate of the timer clock. The timer frequency is of course needed very early in the boot, and as a consequence, we need to shuffle around the early PRCMU init code: whereas in the past we did not need to look up the PRCMU firmware version in the early init, but now we need to know the version before the core system timers are registered so we restructure the platform callbacks to the PRCMU so as not to take any arguments and instead look up the resources it needs directly from the device tree when initializing. As we do not yet support any platforms using this firmware it is not a regression, but as PostmarketOS is starting to support products with this firmware we need to fix this up. The low rate of 32kHz also makes the MTU timer unsuitable as delay timer but this needs to be fixed in a separate patch. Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Stephan Gerhold <stephan@gerhold.net> Acked-by: Olof Johansson <olof@lixom.net> Signed-off-by: Lee Jones <lee.jones@linaro.org>
139 lines
3.6 KiB
C
139 lines
3.6 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (C) 2008-2009 ST-Ericsson SA
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*
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* Author: Srinidhi KASAGAR <srinidhi.kasagar@stericsson.com>
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*/
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#include <linux/types.h>
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#include <linux/init.h>
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#include <linux/device.h>
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#include <linux/amba/bus.h>
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#include <linux/interrupt.h>
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#include <linux/irq.h>
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#include <linux/irqchip.h>
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#include <linux/irqchip/arm-gic.h>
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#include <linux/mfd/dbx500-prcmu.h>
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#include <linux/platform_data/arm-ux500-pm.h>
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#include <linux/platform_device.h>
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#include <linux/io.h>
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#include <linux/of.h>
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#include <linux/of_address.h>
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#include <linux/of_platform.h>
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#include <linux/regulator/machine.h>
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#include <asm/outercache.h>
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#include <asm/hardware/cache-l2x0.h>
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#include <asm/mach/map.h>
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#include <asm/mach/arch.h>
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#include "db8500-regs.h"
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#include "pm_domains.h"
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static int __init ux500_l2x0_unlock(void)
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{
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int i;
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struct device_node *np;
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void __iomem *l2x0_base;
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np = of_find_compatible_node(NULL, NULL, "arm,pl310-cache");
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l2x0_base = of_iomap(np, 0);
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of_node_put(np);
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if (!l2x0_base)
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return -ENODEV;
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/*
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* Unlock Data and Instruction Lock if locked. Ux500 U-Boot versions
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* apparently locks both caches before jumping to the kernel. The
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* l2x0 core will not touch the unlock registers if the l2x0 is
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* already enabled, so we do it right here instead. The PL310 has
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* 8 sets of registers, one per possible CPU.
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*/
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for (i = 0; i < 8; i++) {
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writel_relaxed(0x0, l2x0_base + L2X0_LOCKDOWN_WAY_D_BASE +
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i * L2X0_LOCKDOWN_STRIDE);
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writel_relaxed(0x0, l2x0_base + L2X0_LOCKDOWN_WAY_I_BASE +
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i * L2X0_LOCKDOWN_STRIDE);
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}
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iounmap(l2x0_base);
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return 0;
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}
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static void ux500_l2c310_write_sec(unsigned long val, unsigned reg)
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{
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/*
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* We can't write to secure registers as we are in non-secure
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* mode, until we have some SMI service available.
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*/
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}
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/*
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* FIXME: Should we set up the GPIO domain here?
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*
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* The problem is that we cannot put the interrupt resources into the platform
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* device until the irqdomain has been added. Right now, we set the GIC interrupt
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* domain from init_irq(), then load the gpio driver from
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* core_initcall(nmk_gpio_init) and add the platform devices from
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* arch_initcall(customize_machine).
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*
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* This feels fragile because it depends on the gpio device getting probed
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* _before_ any device uses the gpio interrupts.
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*/
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static void __init ux500_init_irq(void)
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{
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struct device_node *np;
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struct resource r;
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irqchip_init();
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prcmu_early_init();
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np = of_find_compatible_node(NULL, NULL, "stericsson,db8500-prcmu");
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of_address_to_resource(np, 0, &r);
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of_node_put(np);
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if (!r.start) {
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pr_err("could not find PRCMU base resource\n");
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return;
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}
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ux500_pm_init(r.start, r.end-r.start);
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/* Unlock before init */
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ux500_l2x0_unlock();
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outer_cache.write_sec = ux500_l2c310_write_sec;
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}
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static void ux500_restart(enum reboot_mode mode, const char *cmd)
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{
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local_irq_disable();
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local_fiq_disable();
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prcmu_system_reset(0);
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}
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static const struct of_device_id u8500_local_bus_nodes[] = {
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/* only create devices below soc node */
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{ .compatible = "stericsson,db8500", },
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{ .compatible = "simple-bus"},
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{ },
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};
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static void __init u8500_init_machine(void)
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{
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/* Initialize ux500 power domains */
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ux500_pm_domains_init();
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of_platform_populate(NULL, u8500_local_bus_nodes,
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NULL, NULL);
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}
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static const char * stericsson_dt_platform_compat[] = {
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"st-ericsson,u8500",
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"st-ericsson,u9500",
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NULL,
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};
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DT_MACHINE_START(U8500_DT, "ST-Ericsson Ux5x0 platform (Device Tree Support)")
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.l2c_aux_val = 0,
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.l2c_aux_mask = ~0,
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.init_irq = ux500_init_irq,
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.init_machine = u8500_init_machine,
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.dt_compat = stericsson_dt_platform_compat,
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.restart = ux500_restart,
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MACHINE_END
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