target/linux/realtek/files-5.10/arch/mips/kernel/cevt-rtl9300.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2
   3 #include <linux/clockchips.h>
   4 #include <linux/init.h>
   5 #include <asm/time.h>
   6 #include <asm/idle.h>
   7 #include <linux/interrupt.h>
   8 #include <linux/of_address.h>
   9 #include <linux/of_irq.h>
  10 #include <linux/sched_clock.h>
  11
  12 #include <mach-rtl83xx.h>
  13
  14 /*
  15  * Timer registers
  16  * the RTL9300/9310 SoCs have 6 timers, each register block 0x10 apart
  17  */
  18 #define RTL9300_TC_DATA         0x0
  19 #define RTL9300_TC_CNT          0x4
  20 #define RTL9300_TC_CTRL         0x8
  21 #define RTL9300_TC_CTRL_MODE    BIT(24)
  22 #define RTL9300_TC_CTRL_EN      BIT(28)
  23 #define RTL9300_TC_INT          0xc
  24 #define RTL9300_TC_INT_IP       BIT(16)
  25 #define RTL9300_TC_INT_IE       BIT(20)
  26
  27 // Timer modes
  28 #define TIMER_MODE_REPEAT       1
  29 #define TIMER_MODE_ONCE         0
  30
  31 // Minimum divider is 2
  32 #define DIVISOR_RTL9300         2
  33
  34 #define N_BITS                  28
  35
  36 #define RTL9300_CLOCK_RATE      87500000
  37
  38 struct rtl9300_clk_dev {
  39         struct clock_event_device clkdev;
  40         void __iomem *base;
  41 };
  42
  43 static void __iomem *rtl9300_tc_base(struct clock_event_device *clk)
  44 {
  45         struct rtl9300_clk_dev *rtl_clk = container_of(clk, struct rtl9300_clk_dev, clkdev);
  46
  47         return rtl_clk->base;
  48 }
  49
  50 static irqreturn_t rtl9300_timer_interrupt(int irq, void *dev_id)
  51 {
  52         struct rtl9300_clk_dev *rtl_clk = dev_id;
  53         struct clock_event_device *clk = &rtl_clk->clkdev;
  54
  55         u32 v = readl(rtl_clk->base + RTL9300_TC_INT);
  56
  57         // Acknowledge the IRQ
  58         v |= RTL9300_TC_INT_IP;
  59         writel(v, rtl_clk->base + RTL9300_TC_INT);
  60
  61         clk->event_handler(clk);
  62         return IRQ_HANDLED;
  63 }
  64
  65 static void rtl9300_clock_stop(void __iomem *base)
  66 {
  67         u32 v;
  68
  69         writel(0, base + RTL9300_TC_CTRL);
  70
  71         // Acknowledge possibly pending IRQ
  72         v = readl(base + RTL9300_TC_INT);
  73         writel(v | RTL9300_TC_INT_IP, base + RTL9300_TC_INT);
  74 }
  75
  76 static void rtl9300_timer_start(void __iomem *base, bool periodic)
  77 {
  78         u32 v = (periodic ? RTL9300_TC_CTRL_MODE : 0) | RTL9300_TC_CTRL_EN | DIVISOR_RTL9300;
  79
  80         writel(0, base + RTL9300_TC_CNT);
  81         pr_debug("------------- starting timer base %08x\n", (u32)base);
  82         writel(v, base + RTL9300_TC_CTRL);
  83 }
  84
  85 static int rtl9300_next_event(unsigned long delta, struct clock_event_device *clk)
  86 {
  87         void __iomem *base = rtl9300_tc_base(clk);
  88
  89         rtl9300_clock_stop(base);
  90         writel(delta, base + RTL9300_TC_DATA);
  91         rtl9300_timer_start(base, TIMER_MODE_ONCE);
  92
  93         return 0;
  94 }
  95
  96 static int rtl9300_state_periodic(struct clock_event_device *clk)
  97 {
  98         void __iomem *base = rtl9300_tc_base(clk);
  99
 100         pr_debug("------------- rtl9300_state_periodic %08x\n", (u32)base);
 101         rtl9300_clock_stop(base);
 102         writel(RTL9300_CLOCK_RATE / HZ, base + RTL9300_TC_DATA);
 103         rtl9300_timer_start(base, TIMER_MODE_REPEAT);
 104         return 0;
 105 }
 106
 107 static int rtl9300_state_oneshot(struct clock_event_device *clk)
 108 {
 109         void __iomem *base = rtl9300_tc_base(clk);
 110
 111         pr_debug("------------- rtl9300_state_oneshot %08x\n", (u32)base);
 112         rtl9300_clock_stop(base);
 113         writel(RTL9300_CLOCK_RATE / HZ, base + RTL9300_TC_DATA);
 114         rtl9300_timer_start(base, TIMER_MODE_ONCE);
 115         return 0;
 116 }
 117
 118 static int rtl9300_shutdown(struct clock_event_device *clk)
 119 {
 120         void __iomem *base = rtl9300_tc_base(clk);
 121
 122         pr_debug("------------- rtl9300_shutdown %08x\n", (u32)base);
 123         rtl9300_clock_stop(base);
 124         return 0;
 125 }
 126
 127 static void rtl9300_clock_setup(void __iomem *base)
 128 {
 129         u32 v;
 130
 131         // Disable timer
 132         writel(0, base + RTL9300_TC_CTRL);
 133
 134         // Acknowledge possibly pending IRQ
 135         v = readl(base + RTL9300_TC_INT);
 136         writel(v | RTL9300_TC_INT_IP, base + RTL9300_TC_INT);
 137
 138         // Setup maximum period (for use as clock-source)
 139         writel(0x0fffffff, base + RTL9300_TC_DATA);
 140 }
 141
 142 static DEFINE_PER_CPU(struct rtl9300_clk_dev, rtl9300_clockevent);
 143 static DEFINE_PER_CPU(char [18], rtl9300_clock_name);
 144
 145 void rtl9300_clockevent_init(void)
 146 {
 147         int cpu = smp_processor_id();
 148         int irq;
 149         struct rtl9300_clk_dev *rtl_clk = &per_cpu(rtl9300_clockevent, cpu);
 150         struct clock_event_device *cd = &rtl_clk->clkdev;
 151         unsigned char *name = per_cpu(rtl9300_clock_name, cpu);
 152         unsigned long flags =  IRQF_PERCPU | IRQF_TIMER;
 153         struct device_node *node;
 154
 155         pr_info("%s called for cpu%d\n", __func__, cpu);
 156         BUG_ON(cpu > 3);        /* Only have 4 general purpose timers */
 157
 158         node = of_find_compatible_node(NULL, NULL, "realtek,rtl9300clock");
 159         if (!node) {
 160                 pr_err("No DT entry found for realtek,rtl9300clock\n");
 161                 return;
 162         }
 163
 164         irq = irq_of_parse_and_map(node, cpu);
 165         pr_info("%s using IRQ %d\n", __func__, irq);
 166
 167         rtl_clk->base = of_iomap(node, cpu);
 168         if (!rtl_clk->base) {
 169                 pr_err("cannot map timer for cpu %d", cpu);
 170                 return;
 171         }
 172
 173         rtl9300_clock_setup(rtl_clk->base);
 174
 175         sprintf(name, "rtl9300-counter-%d", cpu);
 176         cd->name                = name;
 177         cd->features            = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT;
 178
 179         clockevent_set_clock(cd, RTL9300_CLOCK_RATE);
 180
 181         cd->max_delta_ns        = clockevent_delta2ns(0x0fffffff, cd);
 182         cd->max_delta_ticks     = 0x0fffffff;
 183         cd->min_delta_ns        = clockevent_delta2ns(0x20, cd);
 184         cd->min_delta_ticks     = 0x20;
 185         cd->rating              = 300;
 186         cd->irq                 = irq;
 187         cd->cpumask             = cpumask_of(cpu);
 188         cd->set_next_event      = rtl9300_next_event;
 189         cd->set_state_shutdown  = rtl9300_shutdown;
 190         cd->set_state_periodic  = rtl9300_state_periodic;
 191         cd->set_state_oneshot   = rtl9300_state_oneshot;
 192         clockevents_register_device(cd);
 193
 194         irq_set_affinity(irq, cd->cpumask);
 195
 196         if (request_irq(irq, rtl9300_timer_interrupt, flags, name, rtl_clk))
 197                 pr_err("Failed to request irq %d (%s)\n", irq, name);
 198
 199         writel(RTL9300_TC_INT_IE, rtl_clk->base + RTL9300_TC_INT);
 200 }