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