linux/drivers/clk/axis/clk-artpec6.c
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   1/*
   2 * ARTPEC-6 clock initialization
   3 *
   4 * Copyright 2015-2016 Axis Comunications AB.
   5 *
   6 * This program is free software; you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License version 2 as
   8 * published by the Free Software Foundation.
   9 */
  10
  11#include <linux/clk-provider.h>
  12#include <linux/device.h>
  13#include <linux/io.h>
  14#include <linux/of.h>
  15#include <linux/of_address.h>
  16#include <linux/platform_device.h>
  17#include <linux/slab.h>
  18#include <dt-bindings/clock/axis,artpec6-clkctrl.h>
  19
  20#define NUM_I2S_CLOCKS 2
  21
  22struct artpec6_clkctrl_drvdata {
  23        struct clk *clk_table[ARTPEC6_CLK_NUMCLOCKS];
  24        void __iomem *syscon_base;
  25        struct clk_onecell_data clk_data;
  26        spinlock_t i2scfg_lock;
  27};
  28
  29static struct artpec6_clkctrl_drvdata *clkdata;
  30
  31static const char *const i2s_clk_names[NUM_I2S_CLOCKS] = {
  32        "i2s0",
  33        "i2s1",
  34};
  35
  36static const int i2s_clk_indexes[NUM_I2S_CLOCKS] = {
  37        ARTPEC6_CLK_I2S0_CLK,
  38        ARTPEC6_CLK_I2S1_CLK,
  39};
  40
  41static void of_artpec6_clkctrl_setup(struct device_node *np)
  42{
  43        int i;
  44        const char *sys_refclk_name;
  45        u32 pll_mode, pll_m, pll_n;
  46        struct clk **clks;
  47
  48        /* Mandatory parent clock. */
  49        i = of_property_match_string(np, "clock-names", "sys_refclk");
  50        if (i < 0)
  51                return;
  52
  53        sys_refclk_name = of_clk_get_parent_name(np, i);
  54
  55        clkdata = kzalloc(sizeof(*clkdata), GFP_KERNEL);
  56        if (!clkdata)
  57                return;
  58
  59        clks = clkdata->clk_table;
  60
  61        for (i = 0; i < ARTPEC6_CLK_NUMCLOCKS; ++i)
  62                clks[i] = ERR_PTR(-EPROBE_DEFER);
  63
  64        clkdata->syscon_base = of_iomap(np, 0);
  65        BUG_ON(clkdata->syscon_base == NULL);
  66
  67        /* Read PLL1 factors configured by boot strap pins. */
  68        pll_mode = (readl(clkdata->syscon_base) >> 6) & 3;
  69        switch (pll_mode) {
  70        case 0:         /* DDR3-2133 mode */
  71                pll_m = 4;
  72                pll_n = 85;
  73                break;
  74        case 1:         /* DDR3-1866 mode */
  75                pll_m = 6;
  76                pll_n = 112;
  77                break;
  78        case 2:         /* DDR3-1600 mode */
  79                pll_m = 4;
  80                pll_n = 64;
  81                break;
  82        case 3:         /* DDR3-1333 mode */
  83                pll_m = 8;
  84                pll_n = 106;
  85                break;
  86        }
  87
  88        clks[ARTPEC6_CLK_CPU] =
  89            clk_register_fixed_factor(NULL, "cpu", sys_refclk_name, 0, pll_n,
  90                                      pll_m);
  91        clks[ARTPEC6_CLK_CPU_PERIPH] =
  92            clk_register_fixed_factor(NULL, "cpu_periph", "cpu", 0, 1, 2);
  93
  94        /* EPROBE_DEFER on the apb_clock is not handled in amba devices. */
  95        clks[ARTPEC6_CLK_UART_PCLK] =
  96            clk_register_fixed_factor(NULL, "uart_pclk", "cpu", 0, 1, 8);
  97        clks[ARTPEC6_CLK_UART_REFCLK] =
  98            clk_register_fixed_rate(NULL, "uart_ref", sys_refclk_name, 0,
  99                                    50000000);
 100
 101        clks[ARTPEC6_CLK_SPI_PCLK] =
 102            clk_register_fixed_factor(NULL, "spi_pclk", "cpu", 0, 1, 8);
 103        clks[ARTPEC6_CLK_SPI_SSPCLK] =
 104            clk_register_fixed_rate(NULL, "spi_sspclk", sys_refclk_name, 0,
 105                                    50000000);
 106
 107        clks[ARTPEC6_CLK_DBG_PCLK] =
 108            clk_register_fixed_factor(NULL, "dbg_pclk", "cpu", 0, 1, 8);
 109
 110        clkdata->clk_data.clks = clkdata->clk_table;
 111        clkdata->clk_data.clk_num = ARTPEC6_CLK_NUMCLOCKS;
 112
 113        of_clk_add_provider(np, of_clk_src_onecell_get, &clkdata->clk_data);
 114}
 115
 116CLK_OF_DECLARE_DRIVER(artpec6_clkctrl, "axis,artpec6-clkctrl",
 117                      of_artpec6_clkctrl_setup);
 118
 119static int artpec6_clkctrl_probe(struct platform_device *pdev)
 120{
 121        int propidx;
 122        struct device_node *np = pdev->dev.of_node;
 123        struct device *dev = &pdev->dev;
 124        struct clk **clks = clkdata->clk_table;
 125        const char *sys_refclk_name;
 126        const char *i2s_refclk_name = NULL;
 127        const char *frac_clk_name[2] = { NULL, NULL };
 128        const char *i2s_mux_parents[2];
 129        u32 muxreg;
 130        int i;
 131        int err = 0;
 132
 133        /* Mandatory parent clock. */
 134        propidx = of_property_match_string(np, "clock-names", "sys_refclk");
 135        if (propidx < 0)
 136                return -EINVAL;
 137
 138        sys_refclk_name = of_clk_get_parent_name(np, propidx);
 139
 140        /* Find clock names of optional parent clocks. */
 141        propidx = of_property_match_string(np, "clock-names", "i2s_refclk");
 142        if (propidx >= 0)
 143                i2s_refclk_name = of_clk_get_parent_name(np, propidx);
 144
 145        propidx = of_property_match_string(np, "clock-names", "frac_clk0");
 146        if (propidx >= 0)
 147                frac_clk_name[0] = of_clk_get_parent_name(np, propidx);
 148        propidx = of_property_match_string(np, "clock-names", "frac_clk1");
 149        if (propidx >= 0)
 150                frac_clk_name[1] = of_clk_get_parent_name(np, propidx);
 151
 152        spin_lock_init(&clkdata->i2scfg_lock);
 153
 154        clks[ARTPEC6_CLK_NAND_CLKA] =
 155            clk_register_fixed_factor(dev, "nand_clka", "cpu", 0, 1, 8);
 156        clks[ARTPEC6_CLK_NAND_CLKB] =
 157            clk_register_fixed_rate(dev, "nand_clkb", sys_refclk_name, 0,
 158                                    100000000);
 159        clks[ARTPEC6_CLK_ETH_ACLK] =
 160            clk_register_fixed_factor(dev, "eth_aclk", "cpu", 0, 1, 4);
 161        clks[ARTPEC6_CLK_DMA_ACLK] =
 162            clk_register_fixed_factor(dev, "dma_aclk", "cpu", 0, 1, 4);
 163        clks[ARTPEC6_CLK_PTP_REF] =
 164            clk_register_fixed_rate(dev, "ptp_ref", sys_refclk_name, 0,
 165                                    100000000);
 166        clks[ARTPEC6_CLK_SD_PCLK] =
 167            clk_register_fixed_rate(dev, "sd_pclk", sys_refclk_name, 0,
 168                                    100000000);
 169        clks[ARTPEC6_CLK_SD_IMCLK] =
 170            clk_register_fixed_rate(dev, "sd_imclk", sys_refclk_name, 0,
 171                                    100000000);
 172        clks[ARTPEC6_CLK_I2S_HST] =
 173            clk_register_fixed_factor(dev, "i2s_hst", "cpu", 0, 1, 8);
 174
 175        for (i = 0; i < NUM_I2S_CLOCKS; ++i) {
 176                if (i2s_refclk_name && frac_clk_name[i]) {
 177                        i2s_mux_parents[0] = frac_clk_name[i];
 178                        i2s_mux_parents[1] = i2s_refclk_name;
 179
 180                        clks[i2s_clk_indexes[i]] =
 181                            clk_register_mux(dev, i2s_clk_names[i],
 182                                             i2s_mux_parents, 2,
 183                                             CLK_SET_RATE_NO_REPARENT |
 184                                             CLK_SET_RATE_PARENT,
 185                                             clkdata->syscon_base + 0x14, i, 1,
 186                                             0, &clkdata->i2scfg_lock);
 187                } else if (frac_clk_name[i]) {
 188                        /* Lock the mux for internal clock reference. */
 189                        muxreg = readl(clkdata->syscon_base + 0x14);
 190                        muxreg &= ~BIT(i);
 191                        writel(muxreg, clkdata->syscon_base + 0x14);
 192                        clks[i2s_clk_indexes[i]] =
 193                            clk_register_fixed_factor(dev, i2s_clk_names[i],
 194                                                      frac_clk_name[i], 0, 1,
 195                                                      1);
 196                } else if (i2s_refclk_name) {
 197                        /* Lock the mux for external clock reference. */
 198                        muxreg = readl(clkdata->syscon_base + 0x14);
 199                        muxreg |= BIT(i);
 200                        writel(muxreg, clkdata->syscon_base + 0x14);
 201                        clks[i2s_clk_indexes[i]] =
 202                            clk_register_fixed_factor(dev, i2s_clk_names[i],
 203                                                      i2s_refclk_name, 0, 1, 1);
 204                }
 205        }
 206
 207        clks[ARTPEC6_CLK_I2C] =
 208            clk_register_fixed_rate(dev, "i2c", sys_refclk_name, 0, 100000000);
 209
 210        clks[ARTPEC6_CLK_SYS_TIMER] =
 211            clk_register_fixed_rate(dev, "timer", sys_refclk_name, 0,
 212                                    100000000);
 213        clks[ARTPEC6_CLK_FRACDIV_IN] =
 214            clk_register_fixed_rate(dev, "fracdiv_in", sys_refclk_name, 0,
 215                                    600000000);
 216
 217        for (i = 0; i < ARTPEC6_CLK_NUMCLOCKS; ++i) {
 218                if (IS_ERR(clks[i]) && PTR_ERR(clks[i]) != -EPROBE_DEFER) {
 219                        dev_err(dev,
 220                                "Failed to register clock at index %d err=%ld\n",
 221                                i, PTR_ERR(clks[i]));
 222                        err = PTR_ERR(clks[i]);
 223                }
 224        }
 225
 226        return err;
 227}
 228
 229static const struct of_device_id artpec_clkctrl_of_match[] = {
 230        { .compatible = "axis,artpec6-clkctrl" },
 231        {}
 232};
 233
 234static struct platform_driver artpec6_clkctrl_driver = {
 235        .probe = artpec6_clkctrl_probe,
 236        .driver = {
 237                   .name = "artpec6_clkctrl",
 238                   .of_match_table = artpec_clkctrl_of_match,
 239        },
 240};
 241
 242builtin_platform_driver(artpec6_clkctrl_driver);
 243