/* * Driver for TI Multi PLL CDCE913/925/937/949 clock synthesizer * * This driver always connects the Y1 to the input clock, Y2/Y3 to PLL1, * Y4/Y5 to PLL2, and so on. PLL frequency is set on a first-come-first-serve * basis. Clients can directly request any frequency that the chip can * deliver using the standard clk framework. In addition, the device can * be configured and activated via the devicetree. * * Copyright (C) 2014, Topic Embedded Products * Licenced under GPL */ #include #include #include #include #include #include #include #include /* Each chip has different number of PLLs and outputs, for example: * The CECE925 has 2 PLLs which can be routed through dividers to 5 outputs. * Model this as 2 PLL clocks which are parents to the outputs. */ enum { CDCE913, CDCE925, CDCE937, CDCE949, }; struct clk_cdce925_chip_info { int num_plls; int num_outputs; }; static const struct clk_cdce925_chip_info clk_cdce925_chip_info_tbl[] = { [CDCE913] = { .num_plls = 1, .num_outputs = 3 }, [CDCE925] = { .num_plls = 2, .num_outputs = 5 }, [CDCE937] = { .num_plls = 3, .num_outputs = 7 }, [CDCE949] = { .num_plls = 4, .num_outputs = 9 }, }; #define MAX_NUMBER_OF_PLLS 4 #define MAX_NUMBER_OF_OUTPUTS 9 #define CDCE925_REG_GLOBAL1 0x01 #define CDCE925_REG_Y1SPIPDIVH 0x02 #define CDCE925_REG_PDIVL 0x03 #define CDCE925_REG_XCSEL 0x05 /* PLL parameters start at 0x10, steps of 0x10 */ #define CDCE925_OFFSET_PLL 0x10 /* Add CDCE925_OFFSET_PLL * (pll) to these registers before sending */ #define CDCE925_PLL_MUX_OUTPUTS 0x14 #define CDCE925_PLL_MULDIV 0x18 #define CDCE925_PLL_FREQUENCY_MIN 80000000ul #define CDCE925_PLL_FREQUENCY_MAX 230000000ul struct clk_cdce925_chip; struct clk_cdce925_output { struct clk_hw hw; struct clk_cdce925_chip *chip; u8 index; u16 pdiv; /* 1..127 for Y2-Y9; 1..1023 for Y1 */ }; #define to_clk_cdce925_output(_hw) \ container_of(_hw, struct clk_cdce925_output, hw) struct clk_cdce925_pll { struct clk_hw hw; struct clk_cdce925_chip *chip; u8 index; u16 m; /* 1..511 */ u16 n; /* 1..4095 */ }; #define to_clk_cdce925_pll(_hw) container_of(_hw, struct clk_cdce925_pll, hw) struct clk_cdce925_chip { struct regmap *regmap; struct i2c_client *i2c_client; const struct clk_cdce925_chip_info *chip_info; struct clk_cdce925_pll pll[MAX_NUMBER_OF_PLLS]; struct clk_cdce925_output clk[MAX_NUMBER_OF_OUTPUTS]; }; /* ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** */ static unsigned long cdce925_pll_calculate_rate(unsigned long parent_rate, u16 n, u16 m) { if ((!m || !n) || (m == n)) return parent_rate; /* In bypass mode runs at same frequency */ return mult_frac(parent_rate, (unsigned long)n, (unsigned long)m); } static unsigned long cdce925_pll_recalc_rate(struct clk_hw *hw, unsigned long parent_rate) { /* Output frequency of PLL is Fout = (Fin/Pdiv)*(N/M) */ struct clk_cdce925_pll *data = to_clk_cdce925_pll(hw); return cdce925_pll_calculate_rate(parent_rate, data->n, data->m); } static void cdce925_pll_find_rate(unsigned long rate, unsigned long parent_rate, u16 *n, u16 *m) { unsigned long un; unsigned long um; unsigned long g; if (rate <= parent_rate) { /* Can always deliver parent_rate in bypass mode */ rate = parent_rate; *n = 0; *m = 0; } else { /* In PLL mode, need to apply min/max range */ if (rate < CDCE925_PLL_FREQUENCY_MIN) rate = CDCE925_PLL_FREQUENCY_MIN; else if (rate > CDCE925_PLL_FREQUENCY_MAX) rate = CDCE925_PLL_FREQUENCY_MAX; g = gcd(rate, parent_rate); um = parent_rate / g; un = rate / g; /* When outside hw range, reduce to fit (rounding errors) */ while ((un > 4095) || (um > 511)) { un >>= 1; um >>= 1; } if (un == 0) un = 1; if (um == 0) um = 1; *n = un; *m = um; } } static long cdce925_pll_round_rate(struct clk_hw *hw, unsigned long rate, unsigned long *parent_rate) { u16 n, m; cdce925_pll_find_rate(rate, *parent_rate, &n, &m); return (long)cdce925_pll_calculate_rate(*parent_rate, n, m); } static int cdce925_pll_set_rate(struct clk_hw *hw, unsigned long rate, unsigned long parent_rate) { struct clk_cdce925_pll *data = to_clk_cdce925_pll(hw); if (!rate || (rate == parent_rate)) { data->m = 0; /* Bypass mode */ data->n = 0; return 0; } if ((rate < CDCE925_PLL_FREQUENCY_MIN) || (rate > CDCE925_PLL_FREQUENCY_MAX)) { pr_debug("%s: rate %lu outside PLL range.\n", __func__, rate); return -EINVAL; } if (rate < parent_rate) { pr_debug("%s: rate %lu less than parent rate %lu.\n", __func__, rate, parent_rate); return -EINVAL; } cdce925_pll_find_rate(rate, parent_rate, &data->n, &data->m); return 0; } /* calculate p = max(0, 4 - int(log2 (n/m))) */ static u8 cdce925_pll_calc_p(u16 n, u16 m) { u8 p; u16 r = n / m; if (r >= 16) return 0; p = 4; while (r > 1) { r >>= 1; --p; } return p; } /* Returns VCO range bits for VCO1_0_RANGE */ static u8 cdce925_pll_calc_range_bits(struct clk_hw *hw, u16 n, u16 m) { struct clk *parent = clk_get_parent(hw->clk); unsigned long rate = clk_get_rate(parent); rate = mult_frac(rate, (unsigned long)n, (unsigned long)m); if (rate >= 175000000) return 0x3; if (rate >= 150000000) return 0x02; if (rate >= 125000000) return 0x01; return 0x00; } /* I2C clock, hence everything must happen in (un)prepare because this * may sleep */ static int cdce925_pll_prepare(struct clk_hw *hw) { struct clk_cdce925_pll *data = to_clk_cdce925_pll(hw); u16 n = data->n; u16 m = data->m; u16 r; u8 q; u8 p; u16 nn; u8 pll[4]; /* Bits are spread out over 4 byte registers */ u8 reg_ofs = data->index * CDCE925_OFFSET_PLL; unsigned i; if ((!m || !n) || (m == n)) { /* Set PLL mux to bypass mode, leave the rest as is */ regmap_update_bits(data->chip->regmap, reg_ofs + CDCE925_PLL_MUX_OUTPUTS, 0x80, 0x80); } else { /* According to data sheet: */ /* p = max(0, 4 - int(log2 (n/m))) */ p = cdce925_pll_calc_p(n, m); /* nn = n * 2^p */ nn = n * BIT(p); /* q = int(nn/m) */ q = nn / m; if ((q < 16) || (q > 63)) { pr_debug("%s invalid q=%d\n", __func__, q); return -EINVAL; } r = nn - (m*q); if (r > 511) { pr_debug("%s invalid r=%d\n", __func__, r); return -EINVAL; } pr_debug("%s n=%d m=%d p=%d q=%d r=%d\n", __func__, n, m, p, q, r); /* encode into register bits */ pll[0] = n >> 4; pll[1] = ((n & 0x0F) << 4) | ((r >> 5) & 0x0F); pll[2] = ((r & 0x1F) << 3) | ((q >> 3) & 0x07); pll[3] = ((q & 0x07) << 5) | (p << 2) | cdce925_pll_calc_range_bits(hw, n, m); /* Write to registers */ for (i = 0; i < ARRAY_SIZE(pll); ++i) regmap_write(data->chip->regmap, reg_ofs + CDCE925_PLL_MULDIV + i, pll[i]); /* Enable PLL */ regmap_update_bits(data->chip->regmap, reg_ofs + CDCE925_PLL_MUX_OUTPUTS, 0x80, 0x00); } return 0; } static void cdce925_pll_unprepare(struct clk_hw *hw) { struct clk_cdce925_pll *data = to_clk_cdce925_pll(hw); u8 reg_ofs = data->index * CDCE925_OFFSET_PLL; regmap_update_bits(data->chip->regmap, reg_ofs + CDCE925_PLL_MUX_OUTPUTS, 0x80, 0x80); } static const struct clk_ops cdce925_pll_ops = { .prepare = cdce925_pll_prepare, .unprepare = cdce925_pll_unprepare, .recalc_rate = cdce925_pll_recalc_rate, .round_rate = cdce925_pll_round_rate, .set_rate = cdce925_pll_set_rate, }; static void cdce925_clk_set_pdiv(struct clk_cdce925_output *data, u16 pdiv) { switch (data->index) { case 0: regmap_update_bits(data->chip->regmap, CDCE925_REG_Y1SPIPDIVH, 0x03, (pdiv >> 8) & 0x03); regmap_write(data->chip->regmap, 0x03, pdiv & 0xFF); break; case 1: regmap_update_bits(data->chip->regmap, 0x16, 0x7F, pdiv); break; case 2: regmap_update_bits(data->chip->regmap, 0x17, 0x7F, pdiv); break; case 3: regmap_update_bits(data->chip->regmap, 0x26, 0x7F, pdiv); break; case 4: regmap_update_bits(data->chip->regmap, 0x27, 0x7F, pdiv); break; case 5: regmap_update_bits(data->chip->regmap, 0x36, 0x7F, pdiv); break; case 6: regmap_update_bits(data->chip->regmap, 0x37, 0x7F, pdiv); break; case 7: regmap_update_bits(data->chip->regmap, 0x46, 0x7F, pdiv); break; case 8: regmap_update_bits(data->chip->regmap, 0x47, 0x7F, pdiv); break; } } static void cdce925_clk_activate(struct clk_cdce925_output *data) { switch (data->index) { case 0: regmap_update_bits(data->chip->regmap, CDCE925_REG_Y1SPIPDIVH, 0x0c, 0x0c); break; case 1: case 2: regmap_update_bits(data->chip->regmap, 0x14, 0x03, 0x03); break; case 3: case 4: regmap_update_bits(data->chip->regmap, 0x24, 0x03, 0x03); break; case 5: case 6: regmap_update_bits(data->chip->regmap, 0x34, 0x03, 0x03); break; case 7: case 8: regmap_update_bits(data->chip->regmap, 0x44, 0x03, 0x03); break; } } static int cdce925_clk_prepare(struct clk_hw *hw) { struct clk_cdce925_output *data = to_clk_cdce925_output(hw); cdce925_clk_set_pdiv(data, data->pdiv); cdce925_clk_activate(data); return 0; } static void cdce925_clk_unprepare(struct clk_hw *hw) { struct clk_cdce925_output *data = to_clk_cdce925_output(hw); /* Disable clock by setting divider to "0" */ cdce925_clk_set_pdiv(data, 0); } static unsigned long cdce925_clk_recalc_rate(struct clk_hw *hw, unsigned long parent_rate) { struct clk_cdce925_output *data = to_clk_cdce925_output(hw); if (data->pdiv) return parent_rate / data->pdiv; return 0; } static u16 cdce925_calc_divider(unsigned long rate, unsigned long parent_rate) { unsigned long divider; if (!rate) return 0; if (rate >= parent_rate) return 1; divider = DIV_ROUND_CLOSEST(parent_rate, rate); if (divider > 0x7F) divider = 0x7F; return (u16)divider; } static unsigned long cdce925_clk_best_parent_rate( struct clk_hw *hw, unsigned long rate) { struct clk *pll = clk_get_parent(hw->clk); struct clk *root = clk_get_parent(pll); unsigned long root_rate = clk_get_rate(root); unsigned long best_rate_error = rate; u16 pdiv_min; u16 pdiv_max; u16 pdiv_best; u16 pdiv_now; if (root_rate % rate == 0) return root_rate; /* Don't need the PLL, use bypass */ pdiv_min = (u16)max(1ul, DIV_ROUND_UP(CDCE925_PLL_FREQUENCY_MIN, rate)); pdiv_max = (u16)min(127ul, CDCE925_PLL_FREQUENCY_MAX / rate); if (pdiv_min > pdiv_max) return 0; /* No can do? */ pdiv_best = pdiv_min; for (pdiv_now = pdiv_min; pdiv_now < pdiv_max; ++pdiv_now) { unsigned long target_rate = rate * pdiv_now; long pll_rate = clk_round_rate(pll, target_rate); unsigned long actual_rate; unsigned long rate_error; if (pll_rate <= 0) continue; actual_rate = pll_rate / pdiv_now; rate_error = abs((long)actual_rate - (long)rate); if (rate_error < best_rate_error) { pdiv_best = pdiv_now; best_rate_error = rate_error; } /* TODO: Consider PLL frequency based on smaller n/m values * and pick the better one if the error is equal */ } return rate * pdiv_best; } static long cdce925_clk_round_rate(struct clk_hw *hw, unsigned long rate, unsigned long *parent_rate) { unsigned long l_parent_rate = *parent_rate; u16 divider = cdce925_calc_divider(rate, l_parent_rate); if (l_parent_rate / divider != rate) { l_parent_rate = cdce925_clk_best_parent_rate(hw, rate); divider = cdce925_calc_divider(rate, l_parent_rate); *parent_rate = l_parent_rate; } if (divider) return (long)(l_parent_rate / divider); return 0; } static int cdce925_clk_set_rate(struct clk_hw *hw, unsigned long rate, unsigned long parent_rate) { struct clk_cdce925_output *data = to_clk_cdce925_output(hw); data->pdiv = cdce925_calc_divider(rate, parent_rate); return 0; } static const struct clk_ops cdce925_clk_ops = { .prepare = cdce925_clk_prepare, .unprepare = cdce925_clk_unprepare, .recalc_rate = cdce925_clk_recalc_rate, .round_rate = cdce925_clk_round_rate, .set_rate = cdce925_clk_set_rate, }; static u16 cdce925_y1_calc_divider(unsigned long rate, unsigned long parent_rate) { unsigned long divider; if (!rate) return 0; if (rate >= parent_rate) return 1; divider = DIV_ROUND_CLOSEST(parent_rate, rate); if (divider > 0x3FF) /* Y1 has 10-bit divider */ divider = 0x3FF; return (u16)divider; } static long cdce925_clk_y1_round_rate(struct clk_hw *hw, unsigned long rate, unsigned long *parent_rate) { unsigned long l_parent_rate = *parent_rate; u16 divider = cdce925_y1_calc_divider(rate, l_parent_rate); if (divider) return (long)(l_parent_rate / divider); return 0; } static int cdce925_clk_y1_set_rate(struct clk_hw *hw, unsigned long rate, unsigned long parent_rate) { struct clk_cdce925_output *data = to_clk_cdce925_output(hw); data->pdiv = cdce925_y1_calc_divider(rate, parent_rate); return 0; } static const struct clk_ops cdce925_clk_y1_ops = { .prepare = cdce925_clk_prepare, .unprepare = cdce925_clk_unprepare, .recalc_rate = cdce925_clk_recalc_rate, .round_rate = cdce925_clk_y1_round_rate, .set_rate = cdce925_clk_y1_set_rate, }; #define CDCE925_I2C_COMMAND_BLOCK_TRANSFER 0x00 #define CDCE925_I2C_COMMAND_BYTE_TRANSFER 0x80 static int cdce925_regmap_i2c_write( void *context, const void *data, size_t count) { struct device *dev = context; struct i2c_client *i2c = to_i2c_client(dev); int ret; u8 reg_data[2]; if (count != 2) return -ENOTSUPP; /* First byte is command code */ reg_data[0] = CDCE925_I2C_COMMAND_BYTE_TRANSFER | ((u8 *)data)[0]; reg_data[1] = ((u8 *)data)[1]; dev_dbg(&i2c->dev, "%s(%zu) %#x %#x\n", __func__, count, reg_data[0], reg_data[1]); ret = i2c_master_send(i2c, reg_data, count); if (likely(ret == count)) return 0; else if (ret < 0) return ret; else return -EIO; } static int cdce925_regmap_i2c_read(void *context, const void *reg, size_t reg_size, void *val, size_t val_size) { struct device *dev = context; struct i2c_client *i2c = to_i2c_client(dev); struct i2c_msg xfer[2]; int ret; u8 reg_data[2]; if (reg_size != 1) return -ENOTSUPP; xfer[0].addr = i2c->addr; xfer[0].flags = 0; xfer[0].buf = reg_data; if (val_size == 1) { reg_data[0] = CDCE925_I2C_COMMAND_BYTE_TRANSFER | ((u8 *)reg)[0]; xfer[0].len = 1; } else { reg_data[0] = CDCE925_I2C_COMMAND_BLOCK_TRANSFER | ((u8 *)reg)[0]; reg_data[1] = val_size; xfer[0].len = 2; } xfer[1].addr = i2c->addr; xfer[1].flags = I2C_M_RD; xfer[1].len = val_size; xfer[1].buf = val; ret = i2c_transfer(i2c->adapter, xfer, 2); if (likely(ret == 2)) { dev_dbg(&i2c->dev, "%s(%zu, %zu) %#x %#x\n", __func__, reg_size, val_size, reg_data[0], *((u8 *)val)); return 0; } else if (ret < 0) return ret; else return -EIO; } static struct clk_hw * of_clk_cdce925_get(struct of_phandle_args *clkspec, void *_data) { struct clk_cdce925_chip *data = _data; unsigned int idx = clkspec->args[0]; if (idx >= ARRAY_SIZE(data->clk)) { pr_err("%s: invalid index %u\n", __func__, idx); return ERR_PTR(-EINVAL); } return &data->clk[idx].hw; } /* The CDCE925 uses a funky way to read/write registers. Bulk mode is * just weird, so just use the single byte mode exclusively. */ static struct regmap_bus regmap_cdce925_bus = { .write = cdce925_regmap_i2c_write, .read = cdce925_regmap_i2c_read, }; static int cdce925_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct clk_cdce925_chip *data; struct device_node *node = client->dev.of_node; const char *parent_name; const char *pll_clk_name[MAX_NUMBER_OF_PLLS] = {NULL,}; struct clk_init_data init = {}; u32 value; int i; int err; struct device_node *np_output; char child_name[6]; struct regmap_config config = { .name = "configuration0", .reg_bits = 8, .val_bits = 8, .cache_type = REGCACHE_RBTREE, }; dev_dbg(&client->dev, "%s\n", __func__); data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL); if (!data) return -ENOMEM; data->i2c_client = client; data->chip_info = &clk_cdce925_chip_info_tbl[id->driver_data]; config.max_register = CDCE925_OFFSET_PLL + data->chip_info->num_plls * 0x10 - 1; data->regmap = devm_regmap_init(&client->dev, ®map_cdce925_bus, &client->dev, &config); if (IS_ERR(data->regmap)) { dev_err(&client->dev, "failed to allocate register map\n"); return PTR_ERR(data->regmap); } i2c_set_clientdata(client, data); parent_name = of_clk_get_parent_name(node, 0); if (!parent_name) { dev_err(&client->dev, "missing parent clock\n"); return -ENODEV; } dev_dbg(&client->dev, "parent is: %s\n", parent_name); if (of_property_read_u32(node, "xtal-load-pf", &value) == 0) regmap_write(data->regmap, CDCE925_REG_XCSEL, (value << 3) & 0xF8); /* PWDN bit */ regmap_update_bits(data->regmap, CDCE925_REG_GLOBAL1, BIT(4), 0); /* Set input source for Y1 to be the XTAL */ regmap_update_bits(data->regmap, 0x02, BIT(7), 0); init.ops = &cdce925_pll_ops; init.flags = 0; init.parent_names = &parent_name; init.num_parents = 1; /* Register PLL clocks */ for (i = 0; i < data->chip_info->num_plls; ++i) { pll_clk_name[i] = kasprintf(GFP_KERNEL, "%s.pll%d", client->dev.of_node->name, i); init.name = pll_clk_name[i]; data->pll[i].chip = data; data->pll[i].hw.init = &init; data->pll[i].index = i; err = devm_clk_hw_register(&client->dev, &data->pll[i].hw); if (err) { dev_err(&client->dev, "Failed register PLL %d\n", i); goto error; } sprintf(child_name, "PLL%d", i+1); np_output = of_get_child_by_name(node, child_name); if (!np_output) continue; if (!of_property_read_u32(np_output, "clock-frequency", &value)) { err = clk_set_rate(data->pll[i].hw.clk, value); if (err) dev_err(&client->dev, "unable to set PLL frequency %ud\n", value); } if (!of_property_read_u32(np_output, "spread-spectrum", &value)) { u8 flag = of_property_read_bool(np_output, "spread-spectrum-center") ? 0x80 : 0x00; regmap_update_bits(data->regmap, 0x16 + (i*CDCE925_OFFSET_PLL), 0x80, flag); regmap_update_bits(data->regmap, 0x12 + (i*CDCE925_OFFSET_PLL), 0x07, value & 0x07); } } /* Register output clock Y1 */ init.ops = &cdce925_clk_y1_ops; init.flags = 0; init.num_parents = 1; init.parent_names = &parent_name; /* Mux Y1 to input */ init.name = kasprintf(GFP_KERNEL, "%s.Y1", client->dev.of_node->name); data->clk[0].chip = data; data->clk[0].hw.init = &init; data->clk[0].index = 0; data->clk[0].pdiv = 1; err = devm_clk_hw_register(&client->dev, &data->clk[0].hw); kfree(init.name); /* clock framework made a copy of the name */ if (err) { dev_err(&client->dev, "clock registration Y1 failed\n"); goto error; } /* Register output clocks Y2 .. Y5*/ init.ops = &cdce925_clk_ops; init.flags = CLK_SET_RATE_PARENT; init.num_parents = 1; for (i = 1; i < data->chip_info->num_outputs; ++i) { init.name = kasprintf(GFP_KERNEL, "%s.Y%d", client->dev.of_node->name, i+1); data->clk[i].chip = data; data->clk[i].hw.init = &init; data->clk[i].index = i; data->clk[i].pdiv = 1; switch (i) { case 1: case 2: /* Mux Y2/3 to PLL1 */ init.parent_names = &pll_clk_name[0]; break; case 3: case 4: /* Mux Y4/5 to PLL2 */ init.parent_names = &pll_clk_name[1]; break; case 5: case 6: /* Mux Y6/7 to PLL3 */ init.parent_names = &pll_clk_name[2]; break; case 7: case 8: /* Mux Y8/9 to PLL4 */ init.parent_names = &pll_clk_name[3]; break; } err = devm_clk_hw_register(&client->dev, &data->clk[i].hw); kfree(init.name); /* clock framework made a copy of the name */ if (err) { dev_err(&client->dev, "clock registration failed\n"); goto error; } } /* Register the output clocks */ err = of_clk_add_hw_provider(client->dev.of_node, of_clk_cdce925_get, data); if (err) dev_err(&client->dev, "unable to add OF clock provider\n"); err = 0; error: for (i = 0; i < data->chip_info->num_plls; ++i) /* clock framework made a copy of the name */ kfree(pll_clk_name[i]); return err; } static const struct i2c_device_id cdce925_id[] = { { "cdce913", CDCE913 }, { "cdce925", CDCE925 }, { "cdce937", CDCE937 }, { "cdce949", CDCE949 }, { } }; MODULE_DEVICE_TABLE(i2c, cdce925_id); static const struct of_device_id clk_cdce925_of_match[] = { { .compatible = "ti,cdce913" }, { .compatible = "ti,cdce925" }, { .compatible = "ti,cdce937" }, { .compatible = "ti,cdce949" }, { }, }; MODULE_DEVICE_TABLE(of, clk_cdce925_of_match); static struct i2c_driver cdce925_driver = { .driver = { .name = "cdce925", .of_match_table = of_match_ptr(clk_cdce925_of_match), }, .probe = cdce925_probe, .id_table = cdce925_id, }; module_i2c_driver(cdce925_driver); MODULE_AUTHOR("Mike Looijmans "); MODULE_DESCRIPTION("TI CDCE913/925/937/949 driver"); MODULE_LICENSE("GPL");