arch/avr32/mach-at32ap/hsmc.c

   1 /*
   2  * Static Memory Controller for AT32 chips
   3  *
   4  * Copyright (C) 2006 Atmel Corporation
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  */
  10 #define DEBUG
  11 #include <linux/clk.h>
  12 #include <linux/err.h>
  13 #include <linux/init.h>
  14 #include <linux/module.h>
  15 #include <linux/platform_device.h>
  16
  17 #include <asm/io.h>
  18 #include <asm/arch/smc.h>
  19
  20 #include "hsmc.h"
  21
  22 #define NR_CHIP_SELECTS 6
  23
  24 struct hsmc {
  25         void __iomem *regs;
  26         struct clk *pclk;
  27         struct clk *mck;
  28 };
  29
  30 static struct hsmc *hsmc;
  31
  32 int smc_set_configuration(int cs, const struct smc_config *config)
  33 {
  34         unsigned long mul;
  35         unsigned long offset;
  36         u32 setup, pulse, cycle, mode;
  37
  38         if (!hsmc)
  39                 return -ENODEV;
  40         if (cs >= NR_CHIP_SELECTS)
  41                 return -EINVAL;
  42
  43         /*
  44          * cycles = x / T = x * f
  45          *   = ((x * 1000000000) * ((f * 65536) / 1000000000)) / 65536
  46          *   = ((x * 1000000000) * (((f / 10000) * 65536) / 100000)) / 65536
  47          */
  48         mul = (clk_get_rate(hsmc->mck) / 10000) << 16;
  49         mul /= 100000;
  50
  51 #define ns2cyc(x) ((((x) * mul) + 65535) >> 16)
  52
  53         setup = (HSMC_BF(NWE_SETUP, ns2cyc(config->nwe_setup))
  54                  | HSMC_BF(NCS_WR_SETUP, ns2cyc(config->ncs_write_setup))
  55                  | HSMC_BF(NRD_SETUP, ns2cyc(config->nrd_setup))
  56                  | HSMC_BF(NCS_RD_SETUP, ns2cyc(config->ncs_read_setup)));
  57         pulse = (HSMC_BF(NWE_PULSE, ns2cyc(config->nwe_pulse))
  58                  | HSMC_BF(NCS_WR_PULSE, ns2cyc(config->ncs_write_pulse))
  59                  | HSMC_BF(NRD_PULSE, ns2cyc(config->nrd_pulse))
  60                  | HSMC_BF(NCS_RD_PULSE, ns2cyc(config->ncs_read_pulse)));
  61         cycle = (HSMC_BF(NWE_CYCLE, ns2cyc(config->write_cycle))
  62                  | HSMC_BF(NRD_CYCLE, ns2cyc(config->read_cycle)));
  63
  64         switch (config->bus_width) {
  65         case 1:
  66                 mode = HSMC_BF(DBW, HSMC_DBW_8_BITS);
  67                 break;
  68         case 2:
  69                 mode = HSMC_BF(DBW, HSMC_DBW_16_BITS);
  70                 break;
  71         case 4:
  72                 mode = HSMC_BF(DBW, HSMC_DBW_32_BITS);
  73                 break;
  74         default:
  75                 return -EINVAL;
  76         }
  77
  78         switch (config->nwait_mode) {
  79         case 0:
  80                 mode |= HSMC_BF(EXNW_MODE, HSMC_EXNW_MODE_DISABLED);
  81                 break;
  82         case 1:
  83                 mode |= HSMC_BF(EXNW_MODE, HSMC_EXNW_MODE_RESERVED);
  84                 break;
  85         case 2:
  86                 mode |= HSMC_BF(EXNW_MODE, HSMC_EXNW_MODE_FROZEN);
  87                 break;
  88         case 3:
  89                 mode |= HSMC_BF(EXNW_MODE, HSMC_EXNW_MODE_READY);
  90                 break;
  91         default:
  92                 return -EINVAL;
  93         }
  94
  95         if (config->tdf_cycles) {
  96                 mode |= HSMC_BF(TDF_CYCLES, config->tdf_cycles);
  97         }
  98
  99         if (config->nrd_controlled)
 100                 mode |= HSMC_BIT(READ_MODE);
 101         if (config->nwe_controlled)
 102                 mode |= HSMC_BIT(WRITE_MODE);
 103         if (config->byte_write)
 104                 mode |= HSMC_BIT(BAT);
 105         if (config->tdf_mode)
 106                 mode |= HSMC_BIT(TDF_MODE);
 107
 108         pr_debug("smc cs%d: setup/%08x pulse/%08x cycle/%08x mode/%08x\n",
 109                  cs, setup, pulse, cycle, mode);
 110
 111         offset = cs * 0x10;
 112         hsmc_writel(hsmc, SETUP0 + offset, setup);
 113         hsmc_writel(hsmc, PULSE0 + offset, pulse);
 114         hsmc_writel(hsmc, CYCLE0 + offset, cycle);
 115         hsmc_writel(hsmc, MODE0 + offset, mode);
 116         hsmc_readl(hsmc, MODE0); /* I/O barrier */
 117
 118         return 0;
 119 }
 120 EXPORT_SYMBOL(smc_set_configuration);
 121
 122 static int hsmc_probe(struct platform_device *pdev)
 123 {
 124         struct resource *regs;
 125         struct clk *pclk, *mck;
 126         int ret;
 127
 128         if (hsmc)
 129                 return -EBUSY;
 130
 131         regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 132         if (!regs)
 133                 return -ENXIO;
 134         pclk = clk_get(&pdev->dev, "pclk");
 135         if (IS_ERR(pclk))
 136                 return PTR_ERR(pclk);
 137         mck = clk_get(&pdev->dev, "mck");
 138         if (IS_ERR(mck)) {
 139                 ret = PTR_ERR(mck);
 140                 goto out_put_pclk;
 141         }
 142
 143         ret = -ENOMEM;
 144         hsmc = kzalloc(sizeof(struct hsmc), GFP_KERNEL);
 145         if (!hsmc)
 146                 goto out_put_clocks;
 147
 148         clk_enable(pclk);
 149         clk_enable(mck);
 150
 151         hsmc->pclk = pclk;
 152         hsmc->mck = mck;
 153         hsmc->regs = ioremap(regs->start, regs->end - regs->start + 1);
 154         if (!hsmc->regs)
 155                 goto out_disable_clocks;
 156
 157         dev_info(&pdev->dev, "Atmel Static Memory Controller at 0x%08lx\n",
 158                  (unsigned long)regs->start);
 159
 160         platform_set_drvdata(pdev, hsmc);
 161
 162         return 0;
 163
 164 out_disable_clocks:
 165         clk_disable(mck);
 166         clk_disable(pclk);
 167         kfree(hsmc);
 168 out_put_clocks:
 169         clk_put(mck);
 170 out_put_pclk:
 171         clk_put(pclk);
 172         hsmc = NULL;
 173         return ret;
 174 }
 175
 176 static struct platform_driver hsmc_driver = {
 177         .probe          = hsmc_probe,
 178         .driver         = {
 179                 .name   = "smc",
 180         },
 181 };
 182
 183 static int __init hsmc_init(void)
 184 {
 185         return platform_driver_register(&hsmc_driver);
 186 }
 187 arch_initcall(hsmc_init);