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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
commit76cb841cb886eef6b3bee341a2266c76578724ad (patch)
treef5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /arch/powerpc/platforms/8xx/m8xx_setup.c
parentInitial commit. (diff)
downloadlinux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz
linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip
Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/powerpc/platforms/8xx/m8xx_setup.c')
-rw-r--r--arch/powerpc/platforms/8xx/m8xx_setup.c238
1 files changed, 238 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/8xx/m8xx_setup.c b/arch/powerpc/platforms/8xx/m8xx_setup.c
new file mode 100644
index 000000000..027c42d89
--- /dev/null
+++ b/arch/powerpc/platforms/8xx/m8xx_setup.c
@@ -0,0 +1,238 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 1995 Linus Torvalds
+ * Adapted from 'alpha' version by Gary Thomas
+ * Modified by Cort Dougan (cort@cs.nmt.edu)
+ * Modified for MBX using prep/chrp/pmac functions by Dan (dmalek@jlc.net)
+ * Further modified for generic 8xx by Dan.
+ */
+
+/*
+ * bootup setup stuff..
+ */
+
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+#include <linux/time.h>
+#include <linux/rtc.h>
+#include <linux/fsl_devices.h>
+
+#include <asm/io.h>
+#include <asm/8xx_immap.h>
+#include <asm/prom.h>
+#include <asm/fs_pd.h>
+#include <mm/mmu_decl.h>
+
+#include "pic.h"
+
+#include "mpc8xx.h"
+
+extern int cpm_pic_init(void);
+extern int cpm_get_irq(void);
+
+/* A place holder for time base interrupts, if they are ever enabled. */
+static irqreturn_t timebase_interrupt(int irq, void *dev)
+{
+ printk ("timebase_interrupt()\n");
+
+ return IRQ_HANDLED;
+}
+
+static struct irqaction tbint_irqaction = {
+ .handler = timebase_interrupt,
+ .flags = IRQF_NO_THREAD,
+ .name = "tbint",
+};
+
+/* per-board overridable init_internal_rtc() function. */
+void __init __attribute__ ((weak))
+init_internal_rtc(void)
+{
+ sit8xx_t __iomem *sys_tmr = immr_map(im_sit);
+
+ /* Disable the RTC one second and alarm interrupts. */
+ clrbits16(&sys_tmr->sit_rtcsc, (RTCSC_SIE | RTCSC_ALE));
+
+ /* Enable the RTC */
+ setbits16(&sys_tmr->sit_rtcsc, (RTCSC_RTF | RTCSC_RTE));
+ immr_unmap(sys_tmr);
+}
+
+static int __init get_freq(char *name, unsigned long *val)
+{
+ struct device_node *cpu;
+ const unsigned int *fp;
+ int found = 0;
+
+ /* The cpu node should have timebase and clock frequency properties */
+ cpu = of_find_node_by_type(NULL, "cpu");
+
+ if (cpu) {
+ fp = of_get_property(cpu, name, NULL);
+ if (fp) {
+ found = 1;
+ *val = *fp;
+ }
+
+ of_node_put(cpu);
+ }
+
+ return found;
+}
+
+/* The decrementer counts at the system (internal) clock frequency divided by
+ * sixteen, or external oscillator divided by four. We force the processor
+ * to use system clock divided by sixteen.
+ */
+void __init mpc8xx_calibrate_decr(void)
+{
+ struct device_node *cpu;
+ cark8xx_t __iomem *clk_r1;
+ car8xx_t __iomem *clk_r2;
+ sitk8xx_t __iomem *sys_tmr1;
+ sit8xx_t __iomem *sys_tmr2;
+ int irq, virq;
+
+ clk_r1 = immr_map(im_clkrstk);
+
+ /* Unlock the SCCR. */
+ out_be32(&clk_r1->cark_sccrk, ~KAPWR_KEY);
+ out_be32(&clk_r1->cark_sccrk, KAPWR_KEY);
+ immr_unmap(clk_r1);
+
+ /* Force all 8xx processors to use divide by 16 processor clock. */
+ clk_r2 = immr_map(im_clkrst);
+ setbits32(&clk_r2->car_sccr, 0x02000000);
+ immr_unmap(clk_r2);
+
+ /* Processor frequency is MHz.
+ */
+ ppc_proc_freq = 50000000;
+ if (!get_freq("clock-frequency", &ppc_proc_freq))
+ printk(KERN_ERR "WARNING: Estimating processor frequency "
+ "(not found)\n");
+
+ ppc_tb_freq = ppc_proc_freq / 16;
+ printk("Decrementer Frequency = 0x%lx\n", ppc_tb_freq);
+
+ /* Perform some more timer/timebase initialization. This used
+ * to be done elsewhere, but other changes caused it to get
+ * called more than once....that is a bad thing.
+ *
+ * First, unlock all of the registers we are going to modify.
+ * To protect them from corruption during power down, registers
+ * that are maintained by keep alive power are "locked". To
+ * modify these registers we have to write the key value to
+ * the key location associated with the register.
+ * Some boards power up with these unlocked, while others
+ * are locked. Writing anything (including the unlock code?)
+ * to the unlocked registers will lock them again. So, here
+ * we guarantee the registers are locked, then we unlock them
+ * for our use.
+ */
+ sys_tmr1 = immr_map(im_sitk);
+ out_be32(&sys_tmr1->sitk_tbscrk, ~KAPWR_KEY);
+ out_be32(&sys_tmr1->sitk_rtcsck, ~KAPWR_KEY);
+ out_be32(&sys_tmr1->sitk_tbk, ~KAPWR_KEY);
+ out_be32(&sys_tmr1->sitk_tbscrk, KAPWR_KEY);
+ out_be32(&sys_tmr1->sitk_rtcsck, KAPWR_KEY);
+ out_be32(&sys_tmr1->sitk_tbk, KAPWR_KEY);
+ immr_unmap(sys_tmr1);
+
+ init_internal_rtc();
+
+ /* Enabling the decrementer also enables the timebase interrupts
+ * (or from the other point of view, to get decrementer interrupts
+ * we have to enable the timebase). The decrementer interrupt
+ * is wired into the vector table, nothing to do here for that.
+ */
+ cpu = of_find_node_by_type(NULL, "cpu");
+ virq= irq_of_parse_and_map(cpu, 0);
+ irq = virq_to_hw(virq);
+
+ sys_tmr2 = immr_map(im_sit);
+ out_be16(&sys_tmr2->sit_tbscr, ((1 << (7 - (irq/2))) << 8) |
+ (TBSCR_TBF | TBSCR_TBE));
+ immr_unmap(sys_tmr2);
+
+ if (setup_irq(virq, &tbint_irqaction))
+ panic("Could not allocate timer IRQ!");
+}
+
+/* The RTC on the MPC8xx is an internal register.
+ * We want to protect this during power down, so we need to unlock,
+ * modify, and re-lock.
+ */
+
+int mpc8xx_set_rtc_time(struct rtc_time *tm)
+{
+ sitk8xx_t __iomem *sys_tmr1;
+ sit8xx_t __iomem *sys_tmr2;
+ time64_t time;
+
+ sys_tmr1 = immr_map(im_sitk);
+ sys_tmr2 = immr_map(im_sit);
+ time = rtc_tm_to_time64(tm);
+
+ out_be32(&sys_tmr1->sitk_rtck, KAPWR_KEY);
+ out_be32(&sys_tmr2->sit_rtc, (u32)time);
+ out_be32(&sys_tmr1->sitk_rtck, ~KAPWR_KEY);
+
+ immr_unmap(sys_tmr2);
+ immr_unmap(sys_tmr1);
+ return 0;
+}
+
+void mpc8xx_get_rtc_time(struct rtc_time *tm)
+{
+ unsigned long data;
+ sit8xx_t __iomem *sys_tmr = immr_map(im_sit);
+
+ /* Get time from the RTC. */
+ data = in_be32(&sys_tmr->sit_rtc);
+ rtc_time64_to_tm(data, tm);
+ immr_unmap(sys_tmr);
+ return;
+}
+
+void __noreturn mpc8xx_restart(char *cmd)
+{
+ car8xx_t __iomem *clk_r = immr_map(im_clkrst);
+
+
+ local_irq_disable();
+
+ setbits32(&clk_r->car_plprcr, 0x00000080);
+ /* Clear the ME bit in MSR to cause checkstop on machine check
+ */
+ mtmsr(mfmsr() & ~0x1000);
+
+ in_8(&clk_r->res[0]);
+ panic("Restart failed\n");
+}
+
+static void cpm_cascade(struct irq_desc *desc)
+{
+ generic_handle_irq(cpm_get_irq());
+}
+
+/* Initialize the internal interrupt controllers. The number of
+ * interrupts supported can vary with the processor type, and the
+ * 82xx family can have up to 64.
+ * External interrupts can be either edge or level triggered, and
+ * need to be initialized by the appropriate driver.
+ */
+void __init mpc8xx_pics_init(void)
+{
+ int irq;
+
+ if (mpc8xx_pic_init()) {
+ printk(KERN_ERR "Failed interrupt 8xx controller initialization\n");
+ return;
+ }
+
+ irq = cpm_pic_init();
+ if (irq)
+ irq_set_chained_handler(irq, cpm_cascade);
+}