linux/drivers/clk/axis/clk-artpec6.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * ARTPEC-6 clock initialization
   4 *
   5 * Copyright 2015-2016 Axis Comunications AB.
   6 */
   7
   8#include <linux/clk-provider.h>
   9#include <linux/device.h>
  10#include <linux/io.h>
  11#include <linux/of.h>
  12#include <linux/of_address.h>
  13#include <linux/platform_device.h>
  14#include <linux/slab.h>
  15#include <dt-bindings/clock/axis,artpec6-clkctrl.h>
  16
  17#define NUM_I2S_CLOCKS 2
  18
  19struct artpec6_clkctrl_drvdata {
  20        struct clk *clk_table[ARTPEC6_CLK_NUMCLOCKS];
  21        void __iomem *syscon_base;
  22        struct clk_onecell_data clk_data;
  23        spinlock_t i2scfg_lock;
  24};
  25
  26static struct artpec6_clkctrl_drvdata *clkdata;
  27
  28static const char *const i2s_clk_names[NUM_I2S_CLOCKS] = {
  29        "i2s0",
  30        "i2s1",
  31};
  32
  33static const int i2s_clk_indexes[NUM_I2S_CLOCKS] = {
  34        ARTPEC6_CLK_I2S0_CLK,
  35        ARTPEC6_CLK_I2S1_CLK,
  36};
  37
  38static void of_artpec6_clkctrl_setup(struct device_node *np)
  39{
  40        int i;
  41        const char *sys_refclk_name;
  42        u32 pll_mode, pll_m, pll_n;
  43        struct clk **clks;
  44
  45        /* Mandatory parent clock. */
  46        i = of_property_match_string(np, "clock-names", "sys_refclk");
  47        if (i < 0)
  48                return;
  49
  50        sys_refclk_name = of_clk_get_parent_name(np, i);
  51
  52        clkdata = kzalloc(sizeof(*clkdata), GFP_KERNEL);
  53        if (!clkdata)
  54                return;
  55
  56        clks = clkdata->clk_table;
  57
  58        for (i = 0; i < ARTPEC6_CLK_NUMCLOCKS; ++i)
  59                clks[i] = ERR_PTR(-EPROBE_DEFER);
  60
  61        clkdata->syscon_base = of_iomap(np, 0);
  62        BUG_ON(clkdata->syscon_base == NULL);
  63
  64        /* Read PLL1 factors configured by boot strap pins. */
  65        pll_mode = (readl(clkdata->syscon_base) >> 6) & 3;
  66        switch (pll_mode) {
  67        case 0:         /* DDR3-2133 mode */
  68                pll_m = 4;
  69                pll_n = 85;
  70                break;
  71        case 1:         /* DDR3-1866 mode */
  72                pll_m = 6;
  73                pll_n = 112;
  74                break;
  75        case 2:         /* DDR3-1600 mode */
  76                pll_m = 4;
  77                pll_n = 64;
  78                break;
  79        case 3:         /* DDR3-1333 mode */
  80                pll_m = 8;
  81                pll_n = 106;
  82                break;
  83        }
  84
  85        clks[ARTPEC6_CLK_CPU] =
  86            clk_register_fixed_factor(NULL, "cpu", sys_refclk_name, 0, pll_n,
  87                                      pll_m);
  88        clks[ARTPEC6_CLK_CPU_PERIPH] =
  89            clk_register_fixed_factor(NULL, "cpu_periph", "cpu", 0, 1, 2);
  90
  91        /* EPROBE_DEFER on the apb_clock is not handled in amba devices. */
  92        clks[ARTPEC6_CLK_UART_PCLK] =
  93            clk_register_fixed_factor(NULL, "uart_pclk", "cpu", 0, 1, 8);
  94        clks[ARTPEC6_CLK_UART_REFCLK] =
  95            clk_register_fixed_rate(NULL, "uart_ref", sys_refclk_name, 0,
  96                                    50000000);
  97
  98        clks[ARTPEC6_CLK_SPI_PCLK] =
  99            clk_register_fixed_factor(NULL, "spi_pclk", "cpu", 0, 1, 8);
 100        clks[ARTPEC6_CLK_SPI_SSPCLK] =
 101            clk_register_fixed_rate(NULL, "spi_sspclk", sys_refclk_name, 0,
 102                                    50000000);
 103
 104        clks[ARTPEC6_CLK_DBG_PCLK] =
 105            clk_register_fixed_factor(NULL, "dbg_pclk", "cpu", 0, 1, 8);
 106
 107        clkdata->clk_data.clks = clkdata->clk_table;
 108        clkdata->clk_data.clk_num = ARTPEC6_CLK_NUMCLOCKS;
 109
 110        of_clk_add_provider(np, of_clk_src_onecell_get, &clkdata->clk_data);
 111}
 112
 113CLK_OF_DECLARE_DRIVER(artpec6_clkctrl, "axis,artpec6-clkctrl",
 114                      of_artpec6_clkctrl_setup);
 115
 116static int artpec6_clkctrl_probe(struct platform_device *pdev)
 117{
 118        int propidx;
 119        struct device_node *np = pdev->dev.of_node;
 120        struct device *dev = &pdev->dev;
 121        struct clk **clks = clkdata->clk_table;
 122        const char *sys_refclk_name;
 123        const char *i2s_refclk_name = NULL;
 124        const char *frac_clk_name[2] = { NULL, NULL };
 125        const char *i2s_mux_parents[2];
 126        u32 muxreg;
 127        int i;
 128        int err = 0;
 129
 130        /* Mandatory parent clock. */
 131        propidx = of_property_match_string(np, "clock-names", "sys_refclk");
 132        if (propidx < 0)
 133                return -EINVAL;
 134
 135        sys_refclk_name = of_clk_get_parent_name(np, propidx);
 136
 137        /* Find clock names of optional parent clocks. */
 138        propidx = of_property_match_string(np, "clock-names", "i2s_refclk");
 139        if (propidx >= 0)
 140                i2s_refclk_name = of_clk_get_parent_name(np, propidx);
 141
 142        propidx = of_property_match_string(np, "clock-names", "frac_clk0");
 143        if (propidx >= 0)
 144                frac_clk_name[0] = of_clk_get_parent_name(np, propidx);
 145        propidx = of_property_match_string(np, "clock-names", "frac_clk1");
 146        if (propidx >= 0)
 147                frac_clk_name[1] = of_clk_get_parent_name(np, propidx);
 148
 149        spin_lock_init(&clkdata->i2scfg_lock);
 150
 151        clks[ARTPEC6_CLK_NAND_CLKA] =
 152            clk_register_fixed_factor(dev, "nand_clka", "cpu", 0, 1, 8);
 153        clks[ARTPEC6_CLK_NAND_CLKB] =
 154            clk_register_fixed_rate(dev, "nand_clkb", sys_refclk_name, 0,
 155                                    100000000);
 156        clks[ARTPEC6_CLK_ETH_ACLK] =
 157            clk_register_fixed_factor(dev, "eth_aclk", "cpu", 0, 1, 4);
 158        clks[ARTPEC6_CLK_DMA_ACLK] =
 159            clk_register_fixed_factor(dev, "dma_aclk", "cpu", 0, 1, 4);
 160        clks[ARTPEC6_CLK_PTP_REF] =
 161            clk_register_fixed_rate(dev, "ptp_ref", sys_refclk_name, 0,
 162                                    100000000);
 163        clks[ARTPEC6_CLK_SD_PCLK] =
 164            clk_register_fixed_rate(dev, "sd_pclk", sys_refclk_name, 0,
 165                                    100000000);
 166        clks[ARTPEC6_CLK_SD_IMCLK] =
 167            clk_register_fixed_rate(dev, "sd_imclk", sys_refclk_name, 0,
 168                                    100000000);
 169        clks[ARTPEC6_CLK_I2S_HST] =
 170            clk_register_fixed_factor(dev, "i2s_hst", "cpu", 0, 1, 8);
 171
 172        for (i = 0; i < NUM_I2S_CLOCKS; ++i) {
 173                if (i2s_refclk_name && frac_clk_name[i]) {
 174                        i2s_mux_parents[0] = frac_clk_name[i];
 175                        i2s_mux_parents[1] = i2s_refclk_name;
 176
 177                        clks[i2s_clk_indexes[i]] =
 178                            clk_register_mux(dev, i2s_clk_names[i],
 179                                             i2s_mux_parents, 2,
 180                                             CLK_SET_RATE_NO_REPARENT |
 181                                             CLK_SET_RATE_PARENT,
 182                                             clkdata->syscon_base + 0x14, i, 1,
 183                                             0, &clkdata->i2scfg_lock);
 184                } else if (frac_clk_name[i]) {
 185                        /* Lock the mux for internal clock reference. */
 186                        muxreg = readl(clkdata->syscon_base + 0x14);
 187                        muxreg &= ~BIT(i);
 188                        writel(muxreg, clkdata->syscon_base + 0x14);
 189                        clks[i2s_clk_indexes[i]] =
 190                            clk_register_fixed_factor(dev, i2s_clk_names[i],
 191                                                      frac_clk_name[i], 0, 1,
 192                                                      1);
 193                } else if (i2s_refclk_name) {
 194                        /* Lock the mux for external clock reference. */
 195                        muxreg = readl(clkdata->syscon_base + 0x14);
 196                        muxreg |= BIT(i);
 197                        writel(muxreg, clkdata->syscon_base + 0x14);
 198                        clks[i2s_clk_indexes[i]] =
 199                            clk_register_fixed_factor(dev, i2s_clk_names[i],
 200                                                      i2s_refclk_name, 0, 1, 1);
 201                }
 202        }
 203
 204        clks[ARTPEC6_CLK_I2C] =
 205            clk_register_fixed_rate(dev, "i2c", sys_refclk_name, 0, 100000000);
 206
 207        clks[ARTPEC6_CLK_SYS_TIMER] =
 208            clk_register_fixed_rate(dev, "timer", sys_refclk_name, 0,
 209                                    100000000);
 210        clks[ARTPEC6_CLK_FRACDIV_IN] =
 211            clk_register_fixed_rate(dev, "fracdiv_in", sys_refclk_name, 0,
 212                                    600000000);
 213
 214        for (i = 0; i < ARTPEC6_CLK_NUMCLOCKS; ++i) {
 215                if (IS_ERR(clks[i]) && PTR_ERR(clks[i]) != -EPROBE_DEFER) {
 216                        dev_err(dev,
 217                                "Failed to register clock at index %d err=%ld\n",
 218                                i, PTR_ERR(clks[i]));
 219                        err = PTR_ERR(clks[i]);
 220                }
 221        }
 222
 223        return err;
 224}
 225
 226static const struct of_device_id artpec_clkctrl_of_match[] = {
 227        { .compatible = "axis,artpec6-clkctrl" },
 228        {}
 229};
 230
 231static struct platform_driver artpec6_clkctrl_driver = {
 232        .probe = artpec6_clkctrl_probe,
 233        .driver = {
 234                   .name = "artpec6_clkctrl",
 235                   .of_match_table = artpec_clkctrl_of_match,
 236        },
 237};
 238
 239builtin_platform_driver(artpec6_clkctrl_driver);
 240