drivers/clk/imx/clk.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/bits.h>
   3 #include <linux/clk.h>
   4 #include <linux/clk-provider.h>
   5 #include <linux/err.h>
   6 #include <linux/io.h>
   7 #include <linux/module.h>
   8 #include <linux/of.h>
   9 #include <linux/slab.h>
  10 #include <linux/spinlock.h>
  11 #include "clk.h"
  12
  13 #define CCM_CCDR                        0x4
  14 #define CCDR_MMDC_CH0_MASK              BIT(17)
  15 #define CCDR_MMDC_CH1_MASK              BIT(16)
  16
  17 DEFINE_SPINLOCK(imx_ccm_lock);
  18 EXPORT_SYMBOL_GPL(imx_ccm_lock);
  19
  20 bool mcore_booted;
  21 EXPORT_SYMBOL_GPL(mcore_booted);
  22
  23 void imx_unregister_hw_clocks(struct clk_hw *hws[], unsigned int count)
  24 {
  25         unsigned int i;
  26
  27         for (i = 0; i < count; i++)
  28                 clk_hw_unregister(hws[i]);
  29 }
  30 EXPORT_SYMBOL_GPL(imx_unregister_hw_clocks);
  31
  32 void imx_mmdc_mask_handshake(void __iomem *ccm_base,
  33                                     unsigned int chn)
  34 {
  35         unsigned int reg;
  36
  37         reg = readl_relaxed(ccm_base + CCM_CCDR);
  38         reg |= chn == 0 ? CCDR_MMDC_CH0_MASK : CCDR_MMDC_CH1_MASK;
  39         writel_relaxed(reg, ccm_base + CCM_CCDR);
  40 }
  41
  42 void imx_check_clocks(struct clk *clks[], unsigned int count)
  43 {
  44         unsigned i;
  45
  46         for (i = 0; i < count; i++)
  47                 if (IS_ERR(clks[i]))
  48                         pr_err("i.MX clk %u: register failed with %ld\n",
  49                                i, PTR_ERR(clks[i]));
  50 }
  51
  52 void imx_check_clk_hws(struct clk_hw *clks[], unsigned int count)
  53 {
  54         unsigned int i;
  55
  56         for (i = 0; i < count; i++)
  57                 if (IS_ERR(clks[i]))
  58                         pr_err("i.MX clk %u: register failed with %ld\n",
  59                                i, PTR_ERR(clks[i]));
  60 }
  61 EXPORT_SYMBOL_GPL(imx_check_clk_hws);
  62
  63 static struct clk *imx_obtain_fixed_clock_from_dt(const char *name)
  64 {
  65         struct of_phandle_args phandle;
  66         struct clk *clk = ERR_PTR(-ENODEV);
  67         char *path;
  68
  69         path = kasprintf(GFP_KERNEL, "/clocks/%s", name);
  70         if (!path)
  71                 return ERR_PTR(-ENOMEM);
  72
  73         phandle.np = of_find_node_by_path(path);
  74         kfree(path);
  75
  76         if (phandle.np) {
  77                 clk = of_clk_get_from_provider(&phandle);
  78                 of_node_put(phandle.np);
  79         }
  80         return clk;
  81 }
  82
  83 struct clk *imx_obtain_fixed_clock(
  84                         const char *name, unsigned long rate)
  85 {
  86         struct clk *clk;
  87
  88         clk = imx_obtain_fixed_clock_from_dt(name);
  89         if (IS_ERR(clk))
  90                 clk = imx_clk_fixed(name, rate);
  91         return clk;
  92 }
  93
  94 struct clk_hw *imx_obtain_fixed_clock_hw(
  95                         const char *name, unsigned long rate)
  96 {
  97         struct clk *clk;
  98
  99         clk = imx_obtain_fixed_clock_from_dt(name);
 100         if (IS_ERR(clk))
 101                 clk = imx_clk_fixed(name, rate);
 102         return __clk_get_hw(clk);
 103 }
 104
 105 struct clk_hw *imx_obtain_fixed_of_clock(struct device_node *np,
 106                                          const char *name, unsigned long rate)
 107 {
 108         struct clk *clk = of_clk_get_by_name(np, name);
 109         struct clk_hw *hw;
 110
 111         if (IS_ERR(clk))
 112                 hw = imx_obtain_fixed_clock_hw(name, rate);
 113         else
 114                 hw = __clk_get_hw(clk);
 115
 116         return hw;
 117 }
 118
 119 struct clk_hw *imx_get_clk_hw_by_name(struct device_node *np, const char *name)
 120 {
 121         struct clk *clk;
 122
 123         clk = of_clk_get_by_name(np, name);
 124         if (IS_ERR(clk))
 125                 return ERR_PTR(-ENOENT);
 126
 127         return __clk_get_hw(clk);
 128 }
 129 EXPORT_SYMBOL_GPL(imx_get_clk_hw_by_name);
 130
 131 /*
 132  * This fixups the register CCM_CSCMR1 write value.
 133  * The write/read/divider values of the aclk_podf field
 134  * of that register have the relationship described by
 135  * the following table:
 136  *
 137  * write value       read value        divider
 138  * 3b'000            3b'110            7
 139  * 3b'001            3b'111            8
 140  * 3b'010            3b'100            5
 141  * 3b'011            3b'101            6
 142  * 3b'100            3b'010            3
 143  * 3b'101            3b'011            4
 144  * 3b'110            3b'000            1
 145  * 3b'111            3b'001            2(default)
 146  *
 147  * That's why we do the xor operation below.
 148  */
 149 #define CSCMR1_FIXUP    0x00600000
 150
 151 void imx_cscmr1_fixup(u32 *val)
 152 {
 153         *val ^= CSCMR1_FIXUP;
 154         return;
 155 }
 156
 157 #ifndef MODULE
 158
 159 static bool imx_keep_uart_clocks;
 160 static int imx_enabled_uart_clocks;
 161 static struct clk **imx_uart_clocks;
 162
 163 static int __init imx_keep_uart_clocks_param(char *str)
 164 {
 165         imx_keep_uart_clocks = 1;
 166
 167         return 0;
 168 }
 169 __setup_param("earlycon", imx_keep_uart_earlycon,
 170               imx_keep_uart_clocks_param, 0);
 171 __setup_param("earlyprintk", imx_keep_uart_earlyprintk,
 172               imx_keep_uart_clocks_param, 0);
 173
 174 void imx_register_uart_clocks(void)
 175 {
 176         unsigned int num __maybe_unused;
 177
 178         imx_enabled_uart_clocks = 0;
 179
 180 /* i.MX boards use device trees now.  For build tests without CONFIG_OF, do nothing */
 181 #ifdef CONFIG_OF
 182         if (imx_keep_uart_clocks) {
 183                 int i;
 184
 185                 num = of_clk_get_parent_count(of_stdout);
 186                 if (!num)
 187                         return;
 188
 189                 if (!of_stdout)
 190                         return;
 191
 192                 imx_uart_clocks = kcalloc(num, sizeof(struct clk *), GFP_KERNEL);
 193                 if (!imx_uart_clocks)
 194                         return;
 195
 196                 for (i = 0; i < num; i++) {
 197                         imx_uart_clocks[imx_enabled_uart_clocks] = of_clk_get(of_stdout, i);
 198
 199                         /* Stop if there are no more of_stdout references */
 200                         if (IS_ERR(imx_uart_clocks[imx_enabled_uart_clocks]))
 201                                 return;
 202
 203                         /* Only enable the clock if it's not NULL */
 204                         if (imx_uart_clocks[imx_enabled_uart_clocks])
 205                                 clk_prepare_enable(imx_uart_clocks[imx_enabled_uart_clocks++]);
 206                 }
 207         }
 208 #endif
 209 }
 210
 211 static int __init imx_clk_disable_uart(void)
 212 {
 213         if (imx_keep_uart_clocks && imx_enabled_uart_clocks) {
 214                 int i;
 215
 216                 for (i = 0; i < imx_enabled_uart_clocks; i++) {
 217                         clk_disable_unprepare(imx_uart_clocks[i]);
 218                         clk_put(imx_uart_clocks[i]);
 219                 }
 220         }
 221
 222         kfree(imx_uart_clocks);
 223
 224         return 0;
 225 }
 226 late_initcall_sync(imx_clk_disable_uart);
 227 #endif
 228
 229 MODULE_LICENSE("GPL v2");