arch/arm/mach-cns3xxx/pm.c

   1 /*
   2  * Copyright 2008 Cavium Networks
   3  *
   4  * This file is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License, Version 2, as
   6  * published by the Free Software Foundation.
   7  */
   8
   9 #include <linux/init.h>
  10 #include <linux/module.h>
  11 #include <linux/io.h>
  12 #include <linux/delay.h>
  13 #include <linux/atomic.h>
  14 #include "cns3xxx.h"
  15 #include "pm.h"
  16 #include "core.h"
  17
  18 void cns3xxx_pwr_clk_en(unsigned int block)
  19 {
  20         u32 reg = __raw_readl(PM_CLK_GATE_REG);
  21
  22         reg |= (block & PM_CLK_GATE_REG_MASK);
  23         __raw_writel(reg, PM_CLK_GATE_REG);
  24 }
  25 EXPORT_SYMBOL(cns3xxx_pwr_clk_en);
  26
  27 void cns3xxx_pwr_clk_dis(unsigned int block)
  28 {
  29         u32 reg = __raw_readl(PM_CLK_GATE_REG);
  30
  31         reg &= ~(block & PM_CLK_GATE_REG_MASK);
  32         __raw_writel(reg, PM_CLK_GATE_REG);
  33 }
  34 EXPORT_SYMBOL(cns3xxx_pwr_clk_dis);
  35
  36 void cns3xxx_pwr_power_up(unsigned int block)
  37 {
  38         u32 reg = __raw_readl(PM_PLL_HM_PD_CTRL_REG);
  39
  40         reg &= ~(block & CNS3XXX_PWR_PLL_ALL);
  41         __raw_writel(reg, PM_PLL_HM_PD_CTRL_REG);
  42
  43         /* Wait for 300us for the PLL output clock locked. */
  44         udelay(300);
  45 };
  46 EXPORT_SYMBOL(cns3xxx_pwr_power_up);
  47
  48 void cns3xxx_pwr_power_down(unsigned int block)
  49 {
  50         u32 reg = __raw_readl(PM_PLL_HM_PD_CTRL_REG);
  51
  52         /* write '1' to power down */
  53         reg |= (block & CNS3XXX_PWR_PLL_ALL);
  54         __raw_writel(reg, PM_PLL_HM_PD_CTRL_REG);
  55 };
  56 EXPORT_SYMBOL(cns3xxx_pwr_power_down);
  57
  58 static void cns3xxx_pwr_soft_rst_force(unsigned int block)
  59 {
  60         u32 reg = __raw_readl(PM_SOFT_RST_REG);
  61
  62         /*
  63          * bit 0, 28, 29 => program low to reset,
  64          * the other else program low and then high
  65          */
  66         if (block & 0x30000001) {
  67                 reg &= ~(block & PM_SOFT_RST_REG_MASK);
  68         } else {
  69                 reg &= ~(block & PM_SOFT_RST_REG_MASK);
  70                 __raw_writel(reg, PM_SOFT_RST_REG);
  71                 reg |= (block & PM_SOFT_RST_REG_MASK);
  72         }
  73
  74         __raw_writel(reg, PM_SOFT_RST_REG);
  75 }
  76
  77 void cns3xxx_pwr_soft_rst(unsigned int block)
  78 {
  79         static unsigned int soft_reset;
  80
  81         if (soft_reset & block) {
  82                 /* SPI/I2C/GPIO use the same block, reset once. */
  83                 return;
  84         } else {
  85                 soft_reset |= block;
  86         }
  87         cns3xxx_pwr_soft_rst_force(block);
  88 }
  89 EXPORT_SYMBOL(cns3xxx_pwr_soft_rst);
  90
  91 void cns3xxx_restart(enum reboot_mode mode, const char *cmd)
  92 {
  93         /*
  94          * To reset, we hit the on-board reset register
  95          * in the system FPGA.
  96          */
  97         cns3xxx_pwr_soft_rst(CNS3XXX_PWR_SOFTWARE_RST(GLOBAL));
  98 }
  99
 100 /*
 101  * cns3xxx_cpu_clock - return CPU/L2 clock
 102  *  aclk: cpu clock/2
 103  *  hclk: cpu clock/4
 104  *  pclk: cpu clock/8
 105  */
 106 int cns3xxx_cpu_clock(void)
 107 {
 108         u32 reg = __raw_readl(PM_CLK_CTRL_REG);
 109         int cpu;
 110         int cpu_sel;
 111         int div_sel;
 112
 113         cpu_sel = (reg >> PM_CLK_CTRL_REG_OFFSET_PLL_CPU_SEL) & 0xf;
 114         div_sel = (reg >> PM_CLK_CTRL_REG_OFFSET_CPU_CLK_DIV) & 0x3;
 115
 116         cpu = (300 + ((cpu_sel / 3) * 100) + ((cpu_sel % 3) * 33)) >> div_sel;
 117
 118         return cpu;
 119 }
 120 EXPORT_SYMBOL(cns3xxx_cpu_clock);
 121
 122 atomic_t usb_pwr_ref = ATOMIC_INIT(0);
 123 EXPORT_SYMBOL(usb_pwr_ref);