diff options
Diffstat (limited to 'drivers/clk/clk-axi-clkgen.c')
| -rw-r--r-- | drivers/clk/clk-axi-clkgen.c | 331 |
1 files changed, 331 insertions, 0 deletions
diff --git a/drivers/clk/clk-axi-clkgen.c b/drivers/clk/clk-axi-clkgen.c new file mode 100644 index 000000000000..8137327847c3 --- /dev/null +++ b/drivers/clk/clk-axi-clkgen.c | |||
| @@ -0,0 +1,331 @@ | |||
| 1 | /* | ||
| 2 | * AXI clkgen driver | ||
| 3 | * | ||
| 4 | * Copyright 2012-2013 Analog Devices Inc. | ||
| 5 | * Author: Lars-Peter Clausen <lars@metafoo.de> | ||
| 6 | * | ||
| 7 | * Licensed under the GPL-2. | ||
| 8 | * | ||
| 9 | */ | ||
| 10 | |||
| 11 | #include <linux/platform_device.h> | ||
| 12 | #include <linux/clk-provider.h> | ||
| 13 | #include <linux/clk.h> | ||
| 14 | #include <linux/slab.h> | ||
| 15 | #include <linux/io.h> | ||
| 16 | #include <linux/of.h> | ||
| 17 | #include <linux/module.h> | ||
| 18 | #include <linux/err.h> | ||
| 19 | |||
| 20 | #define AXI_CLKGEN_REG_UPDATE_ENABLE 0x04 | ||
| 21 | #define AXI_CLKGEN_REG_CLK_OUT1 0x08 | ||
| 22 | #define AXI_CLKGEN_REG_CLK_OUT2 0x0c | ||
| 23 | #define AXI_CLKGEN_REG_CLK_DIV 0x10 | ||
| 24 | #define AXI_CLKGEN_REG_CLK_FB1 0x14 | ||
| 25 | #define AXI_CLKGEN_REG_CLK_FB2 0x18 | ||
| 26 | #define AXI_CLKGEN_REG_LOCK1 0x1c | ||
| 27 | #define AXI_CLKGEN_REG_LOCK2 0x20 | ||
| 28 | #define AXI_CLKGEN_REG_LOCK3 0x24 | ||
| 29 | #define AXI_CLKGEN_REG_FILTER1 0x28 | ||
| 30 | #define AXI_CLKGEN_REG_FILTER2 0x2c | ||
| 31 | |||
| 32 | struct axi_clkgen { | ||
| 33 | void __iomem *base; | ||
| 34 | struct clk_hw clk_hw; | ||
| 35 | }; | ||
| 36 | |||
| 37 | static uint32_t axi_clkgen_lookup_filter(unsigned int m) | ||
| 38 | { | ||
| 39 | switch (m) { | ||
| 40 | case 0: | ||
| 41 | return 0x01001990; | ||
| 42 | case 1: | ||
| 43 | return 0x01001190; | ||
| 44 | case 2: | ||
| 45 | return 0x01009890; | ||
| 46 | case 3: | ||
| 47 | return 0x01001890; | ||
| 48 | case 4: | ||
| 49 | return 0x01008890; | ||
| 50 | case 5 ... 8: | ||
| 51 | return 0x01009090; | ||
| 52 | case 9 ... 11: | ||
| 53 | return 0x01000890; | ||
| 54 | case 12: | ||
| 55 | return 0x08009090; | ||
| 56 | case 13 ... 22: | ||
| 57 | return 0x01001090; | ||
| 58 | case 23 ... 36: | ||
| 59 | return 0x01008090; | ||
| 60 | case 37 ... 46: | ||
| 61 | return 0x08001090; | ||
| 62 | default: | ||
| 63 | return 0x08008090; | ||
| 64 | } | ||
| 65 | } | ||
| 66 | |||
| 67 | static const uint32_t axi_clkgen_lock_table[] = { | ||
| 68 | 0x060603e8, 0x060603e8, 0x080803e8, 0x0b0b03e8, | ||
| 69 | 0x0e0e03e8, 0x111103e8, 0x131303e8, 0x161603e8, | ||
| 70 | 0x191903e8, 0x1c1c03e8, 0x1f1f0384, 0x1f1f0339, | ||
| 71 | 0x1f1f02ee, 0x1f1f02bc, 0x1f1f028a, 0x1f1f0271, | ||
| 72 | 0x1f1f023f, 0x1f1f0226, 0x1f1f020d, 0x1f1f01f4, | ||
| 73 | 0x1f1f01db, 0x1f1f01c2, 0x1f1f01a9, 0x1f1f0190, | ||
| 74 | 0x1f1f0190, 0x1f1f0177, 0x1f1f015e, 0x1f1f015e, | ||
| 75 | 0x1f1f0145, 0x1f1f0145, 0x1f1f012c, 0x1f1f012c, | ||
| 76 | 0x1f1f012c, 0x1f1f0113, 0x1f1f0113, 0x1f1f0113, | ||
| 77 | }; | ||
| 78 | |||
| 79 | static uint32_t axi_clkgen_lookup_lock(unsigned int m) | ||
| 80 | { | ||
| 81 | if (m < ARRAY_SIZE(axi_clkgen_lock_table)) | ||
| 82 | return axi_clkgen_lock_table[m]; | ||
| 83 | return 0x1f1f00fa; | ||
| 84 | } | ||
| 85 | |||
| 86 | static const unsigned int fpfd_min = 10000; | ||
| 87 | static const unsigned int fpfd_max = 300000; | ||
| 88 | static const unsigned int fvco_min = 600000; | ||
| 89 | static const unsigned int fvco_max = 1200000; | ||
| 90 | |||
| 91 | static void axi_clkgen_calc_params(unsigned long fin, unsigned long fout, | ||
| 92 | unsigned int *best_d, unsigned int *best_m, unsigned int *best_dout) | ||
| 93 | { | ||
| 94 | unsigned long d, d_min, d_max, _d_min, _d_max; | ||
| 95 | unsigned long m, m_min, m_max; | ||
| 96 | unsigned long f, dout, best_f, fvco; | ||
| 97 | |||
| 98 | fin /= 1000; | ||
| 99 | fout /= 1000; | ||
| 100 | |||
| 101 | best_f = ULONG_MAX; | ||
| 102 | *best_d = 0; | ||
| 103 | *best_m = 0; | ||
| 104 | *best_dout = 0; | ||
| 105 | |||
| 106 | d_min = max_t(unsigned long, DIV_ROUND_UP(fin, fpfd_max), 1); | ||
| 107 | d_max = min_t(unsigned long, fin / fpfd_min, 80); | ||
| 108 | |||
| 109 | m_min = max_t(unsigned long, DIV_ROUND_UP(fvco_min, fin) * d_min, 1); | ||
| 110 | m_max = min_t(unsigned long, fvco_max * d_max / fin, 64); | ||
| 111 | |||
| 112 | for (m = m_min; m <= m_max; m++) { | ||
| 113 | _d_min = max(d_min, DIV_ROUND_UP(fin * m, fvco_max)); | ||
| 114 | _d_max = min(d_max, fin * m / fvco_min); | ||
| 115 | |||
| 116 | for (d = _d_min; d <= _d_max; d++) { | ||
| 117 | fvco = fin * m / d; | ||
| 118 | |||
| 119 | dout = DIV_ROUND_CLOSEST(fvco, fout); | ||
| 120 | dout = clamp_t(unsigned long, dout, 1, 128); | ||
| 121 | f = fvco / dout; | ||
| 122 | if (abs(f - fout) < abs(best_f - fout)) { | ||
| 123 | best_f = f; | ||
| 124 | *best_d = d; | ||
| 125 | *best_m = m; | ||
| 126 | *best_dout = dout; | ||
| 127 | if (best_f == fout) | ||
| 128 | return; | ||
| 129 | } | ||
| 130 | } | ||
| 131 | } | ||
| 132 | } | ||
| 133 | |||
| 134 | static void axi_clkgen_calc_clk_params(unsigned int divider, unsigned int *low, | ||
| 135 | unsigned int *high, unsigned int *edge, unsigned int *nocount) | ||
| 136 | { | ||
| 137 | if (divider == 1) | ||
| 138 | *nocount = 1; | ||
| 139 | else | ||
| 140 | *nocount = 0; | ||
| 141 | |||
| 142 | *high = divider / 2; | ||
| 143 | *edge = divider % 2; | ||
| 144 | *low = divider - *high; | ||
| 145 | } | ||
| 146 | |||
| 147 | static void axi_clkgen_write(struct axi_clkgen *axi_clkgen, | ||
| 148 | unsigned int reg, unsigned int val) | ||
| 149 | { | ||
| 150 | writel(val, axi_clkgen->base + reg); | ||
| 151 | } | ||
| 152 | |||
| 153 | static void axi_clkgen_read(struct axi_clkgen *axi_clkgen, | ||
| 154 | unsigned int reg, unsigned int *val) | ||
| 155 | { | ||
| 156 | *val = readl(axi_clkgen->base + reg); | ||
| 157 | } | ||
| 158 | |||
| 159 | static struct axi_clkgen *clk_hw_to_axi_clkgen(struct clk_hw *clk_hw) | ||
| 160 | { | ||
| 161 | return container_of(clk_hw, struct axi_clkgen, clk_hw); | ||
| 162 | } | ||
| 163 | |||
| 164 | static int axi_clkgen_set_rate(struct clk_hw *clk_hw, | ||
| 165 | unsigned long rate, unsigned long parent_rate) | ||
| 166 | { | ||
| 167 | struct axi_clkgen *axi_clkgen = clk_hw_to_axi_clkgen(clk_hw); | ||
| 168 | unsigned int d, m, dout; | ||
| 169 | unsigned int nocount; | ||
| 170 | unsigned int high; | ||
| 171 | unsigned int edge; | ||
| 172 | unsigned int low; | ||
| 173 | uint32_t filter; | ||
| 174 | uint32_t lock; | ||
| 175 | |||
| 176 | if (parent_rate == 0 || rate == 0) | ||
| 177 | return -EINVAL; | ||
| 178 | |||
| 179 | axi_clkgen_calc_params(parent_rate, rate, &d, &m, &dout); | ||
| 180 | |||
| 181 | if (d == 0 || dout == 0 || m == 0) | ||
| 182 | return -EINVAL; | ||
| 183 | |||
| 184 | filter = axi_clkgen_lookup_filter(m - 1); | ||
| 185 | lock = axi_clkgen_lookup_lock(m - 1); | ||
| 186 | |||
| 187 | axi_clkgen_write(axi_clkgen, AXI_CLKGEN_REG_UPDATE_ENABLE, 0); | ||
| 188 | |||
| 189 | axi_clkgen_calc_clk_params(dout, &low, &high, &edge, &nocount); | ||
| 190 | axi_clkgen_write(axi_clkgen, AXI_CLKGEN_REG_CLK_OUT1, | ||
| 191 | (high << 6) | low); | ||
| 192 | axi_clkgen_write(axi_clkgen, AXI_CLKGEN_REG_CLK_OUT2, | ||
| 193 | (edge << 7) | (nocount << 6)); | ||
| 194 | |||
| 195 | axi_clkgen_calc_clk_params(d, &low, &high, &edge, &nocount); | ||
| 196 | axi_clkgen_write(axi_clkgen, AXI_CLKGEN_REG_CLK_DIV, | ||
| 197 | (edge << 13) | (nocount << 12) | (high << 6) | low); | ||
| 198 | |||
| 199 | axi_clkgen_calc_clk_params(m, &low, &high, &edge, &nocount); | ||
| 200 | axi_clkgen_write(axi_clkgen, AXI_CLKGEN_REG_CLK_FB1, | ||
| 201 | (high << 6) | low); | ||
| 202 | axi_clkgen_write(axi_clkgen, AXI_CLKGEN_REG_CLK_FB2, | ||
| 203 | (edge << 7) | (nocount << 6)); | ||
| 204 | |||
| 205 | axi_clkgen_write(axi_clkgen, AXI_CLKGEN_REG_LOCK1, lock & 0x3ff); | ||
| 206 | axi_clkgen_write(axi_clkgen, AXI_CLKGEN_REG_LOCK2, | ||
| 207 | (((lock >> 16) & 0x1f) << 10) | 0x1); | ||
| 208 | axi_clkgen_write(axi_clkgen, AXI_CLKGEN_REG_LOCK3, | ||
| 209 | (((lock >> 24) & 0x1f) << 10) | 0x3e9); | ||
| 210 | axi_clkgen_write(axi_clkgen, AXI_CLKGEN_REG_FILTER1, filter >> 16); | ||
| 211 | axi_clkgen_write(axi_clkgen, AXI_CLKGEN_REG_FILTER2, filter); | ||
| 212 | |||
| 213 | axi_clkgen_write(axi_clkgen, AXI_CLKGEN_REG_UPDATE_ENABLE, 1); | ||
| 214 | |||
| 215 | return 0; | ||
| 216 | } | ||
| 217 | |||
| 218 | static long axi_clkgen_round_rate(struct clk_hw *hw, unsigned long rate, | ||
| 219 | unsigned long *parent_rate) | ||
| 220 | { | ||
| 221 | unsigned int d, m, dout; | ||
| 222 | |||
| 223 | axi_clkgen_calc_params(*parent_rate, rate, &d, &m, &dout); | ||
| 224 | |||
| 225 | if (d == 0 || dout == 0 || m == 0) | ||
| 226 | return -EINVAL; | ||
| 227 | |||
| 228 | return *parent_rate / d * m / dout; | ||
| 229 | } | ||
| 230 | |||
| 231 | static unsigned long axi_clkgen_recalc_rate(struct clk_hw *clk_hw, | ||
| 232 | unsigned long parent_rate) | ||
| 233 | { | ||
| 234 | struct axi_clkgen *axi_clkgen = clk_hw_to_axi_clkgen(clk_hw); | ||
| 235 | unsigned int d, m, dout; | ||
| 236 | unsigned int reg; | ||
| 237 | unsigned long long tmp; | ||
| 238 | |||
| 239 | axi_clkgen_read(axi_clkgen, AXI_CLKGEN_REG_CLK_OUT1, ®); | ||
| 240 | dout = (reg & 0x3f) + ((reg >> 6) & 0x3f); | ||
| 241 | axi_clkgen_read(axi_clkgen, AXI_CLKGEN_REG_CLK_DIV, ®); | ||
| 242 | d = (reg & 0x3f) + ((reg >> 6) & 0x3f); | ||
| 243 | axi_clkgen_read(axi_clkgen, AXI_CLKGEN_REG_CLK_FB1, ®); | ||
| 244 | m = (reg & 0x3f) + ((reg >> 6) & 0x3f); | ||
| 245 | |||
| 246 | if (d == 0 || dout == 0) | ||
| 247 | return 0; | ||
| 248 | |||
| 249 | tmp = (unsigned long long)(parent_rate / d) * m; | ||
| 250 | do_div(tmp, dout); | ||
| 251 | |||
| 252 | if (tmp > ULONG_MAX) | ||
| 253 | return ULONG_MAX; | ||
| 254 | |||
| 255 | return tmp; | ||
| 256 | } | ||
| 257 | |||
| 258 | static const struct clk_ops axi_clkgen_ops = { | ||
| 259 | .recalc_rate = axi_clkgen_recalc_rate, | ||
| 260 | .round_rate = axi_clkgen_round_rate, | ||
| 261 | .set_rate = axi_clkgen_set_rate, | ||
| 262 | }; | ||
| 263 | |||
| 264 | static int axi_clkgen_probe(struct platform_device *pdev) | ||
| 265 | { | ||
| 266 | struct axi_clkgen *axi_clkgen; | ||
| 267 | struct clk_init_data init; | ||
| 268 | const char *parent_name; | ||
| 269 | const char *clk_name; | ||
| 270 | struct resource *mem; | ||
| 271 | struct clk *clk; | ||
| 272 | |||
| 273 | axi_clkgen = devm_kzalloc(&pdev->dev, sizeof(*axi_clkgen), GFP_KERNEL); | ||
| 274 | if (!axi_clkgen) | ||
| 275 | return -ENOMEM; | ||
| 276 | |||
| 277 | mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); | ||
| 278 | axi_clkgen->base = devm_ioremap_resource(&pdev->dev, mem); | ||
| 279 | if (IS_ERR(axi_clkgen->base)) | ||
| 280 | return PTR_ERR(axi_clkgen->base); | ||
| 281 | |||
| 282 | parent_name = of_clk_get_parent_name(pdev->dev.of_node, 0); | ||
| 283 | if (!parent_name) | ||
| 284 | return -EINVAL; | ||
| 285 | |||
| 286 | clk_name = pdev->dev.of_node->name; | ||
| 287 | of_property_read_string(pdev->dev.of_node, "clock-output-names", | ||
| 288 | &clk_name); | ||
| 289 | |||
| 290 | init.name = clk_name; | ||
| 291 | init.ops = &axi_clkgen_ops; | ||
| 292 | init.flags = 0; | ||
| 293 | init.parent_names = &parent_name; | ||
| 294 | init.num_parents = 1; | ||
| 295 | |||
| 296 | axi_clkgen->clk_hw.init = &init; | ||
| 297 | clk = devm_clk_register(&pdev->dev, &axi_clkgen->clk_hw); | ||
| 298 | if (IS_ERR(clk)) | ||
| 299 | return PTR_ERR(clk); | ||
| 300 | |||
| 301 | return of_clk_add_provider(pdev->dev.of_node, of_clk_src_simple_get, | ||
| 302 | clk); | ||
| 303 | } | ||
| 304 | |||
| 305 | static int axi_clkgen_remove(struct platform_device *pdev) | ||
| 306 | { | ||
| 307 | of_clk_del_provider(pdev->dev.of_node); | ||
| 308 | |||
| 309 | return 0; | ||
| 310 | } | ||
| 311 | |||
| 312 | static const struct of_device_id axi_clkgen_ids[] = { | ||
| 313 | { .compatible = "adi,axi-clkgen-1.00.a" }, | ||
| 314 | { }, | ||
| 315 | }; | ||
| 316 | MODULE_DEVICE_TABLE(of, axi_clkgen_ids); | ||
| 317 | |||
| 318 | static struct platform_driver axi_clkgen_driver = { | ||
| 319 | .driver = { | ||
| 320 | .name = "adi-axi-clkgen", | ||
| 321 | .owner = THIS_MODULE, | ||
| 322 | .of_match_table = axi_clkgen_ids, | ||
| 323 | }, | ||
| 324 | .probe = axi_clkgen_probe, | ||
| 325 | .remove = axi_clkgen_remove, | ||
| 326 | }; | ||
| 327 | module_platform_driver(axi_clkgen_driver); | ||
| 328 | |||
| 329 | MODULE_LICENSE("GPL v2"); | ||
| 330 | MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); | ||
| 331 | MODULE_DESCRIPTION("Driver for the Analog Devices' AXI clkgen pcore clock generator"); | ||
