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 static int imx_keep_uart_clocks;
 151 static struct clk ** const *imx_uart_clocks;
 152
 153 static int __init imx_keep_uart_clocks_param(char *str)
 154 {
 155         imx_keep_uart_clocks = 1;
 156
 157         return 0;
 158 }
 159 __setup_param("earlycon", imx_keep_uart_earlycon,
 160               imx_keep_uart_clocks_param, 0);
 161 __setup_param("earlyprintk", imx_keep_uart_earlyprintk,
 162               imx_keep_uart_clocks_param, 0);
 163
 164 void imx_register_uart_clocks(struct clk ** const clks[])
 165 {
 166         if (imx_keep_uart_clocks) {
 167                 int i;
 168
 169                 imx_uart_clocks = clks;
 170                 for (i = 0; imx_uart_clocks[i]; i++)
 171                         clk_prepare_enable(*imx_uart_clocks[i]);
 172         }
 173 }
 174
 175 static int __init imx_clk_disable_uart(void)
 176 {
 177         if (imx_keep_uart_clocks && imx_uart_clocks) {
 178                 int i;
 179
 180                 for (i = 0; imx_uart_clocks[i]; i++)
 181                         clk_disable_unprepare(*imx_uart_clocks[i]);
 182         }
 183
 184         return 0;
 185 }
 186 late_initcall_sync(imx_clk_disable_uart);
 187 #endif
 188
 189 MODULE_LICENSE("GPL v2");