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