// SPDX-License-Identifier: GPL-2.0-or-later /* * Driver for Skyworks Si521xx PCIe clock generator driver * * The following series can be supported: * - Si52144 - 4x DIFF * - Si52146 - 6x DIFF * - Si52147 - 9x DIFF * Currently tested: * - Si52144 * * Copyright (C) 2022 Marek Vasut */ #include #include #include #include #include #include #include #include /* OE1 and OE2 register */ #define SI521XX_REG_OE(n) (((n) & 0x1) + 1) #define SI521XX_REG_ID 0x3 #define SI521XX_REG_ID_PROG GENMASK(7, 4) #define SI521XX_REG_ID_VENDOR GENMASK(3, 0) #define SI521XX_REG_BC 0x4 #define SI521XX_REG_DA 0x5 #define SI521XX_REG_DA_AMP_SEL BIT(7) #define SI521XX_REG_DA_AMP_MASK GENMASK(6, 4) #define SI521XX_REG_DA_AMP_MIN 300000 #define SI521XX_REG_DA_AMP_DEFAULT 800000 #define SI521XX_REG_DA_AMP_MAX 1000000 #define SI521XX_REG_DA_AMP_STEP 100000 #define SI521XX_REG_DA_AMP(UV) \ FIELD_PREP(SI521XX_REG_DA_AMP_MASK, \ ((UV) - SI521XX_REG_DA_AMP_MIN) / SI521XX_REG_DA_AMP_STEP) #define SI521XX_REG_DA_UNKNOWN BIT(3) /* Always set */ /* Count of populated OE bits in control register ref, 1 and 2 */ #define SI521XX_OE_MAP(cr1, cr2) (((cr2) << 8) | (cr1)) #define SI521XX_OE_MAP_GET_OE(oe, map) (((map) >> (((oe) - 1) * 8)) & 0xff) #define SI521XX_DIFF_MULT 4 #define SI521XX_DIFF_DIV 1 /* Supported Skyworks Si521xx models. */ enum si521xx_model { SI52144 = 0x44, SI52146 = 0x46, SI52147 = 0x47, }; struct si521xx; struct si_clk { struct clk_hw hw; struct si521xx *si; u8 reg; u8 bit; }; struct si521xx { struct i2c_client *client; struct regmap *regmap; struct si_clk clk_dif[9]; u16 chip_info; u8 pll_amplitude; }; /* * Si521xx i2c regmap */ static const struct regmap_range si521xx_readable_ranges[] = { regmap_reg_range(SI521XX_REG_OE(0), SI521XX_REG_DA), }; static const struct regmap_access_table si521xx_readable_table = { .yes_ranges = si521xx_readable_ranges, .n_yes_ranges = ARRAY_SIZE(si521xx_readable_ranges), }; static const struct regmap_range si521xx_writeable_ranges[] = { regmap_reg_range(SI521XX_REG_OE(0), SI521XX_REG_OE(1)), regmap_reg_range(SI521XX_REG_BC, SI521XX_REG_DA), }; static const struct regmap_access_table si521xx_writeable_table = { .yes_ranges = si521xx_writeable_ranges, .n_yes_ranges = ARRAY_SIZE(si521xx_writeable_ranges), }; static int si521xx_regmap_i2c_write(void *context, unsigned int reg, unsigned int val) { struct i2c_client *i2c = context; const u8 data[2] = { reg, val }; const int count = ARRAY_SIZE(data); int ret; ret = i2c_master_send(i2c, data, count); if (ret == count) return 0; else if (ret < 0) return ret; else return -EIO; } static int si521xx_regmap_i2c_read(void *context, unsigned int reg, unsigned int *val) { struct i2c_client *i2c = context; struct i2c_msg xfer[2]; u8 txdata = reg; u8 rxdata[2]; int ret; xfer[0].addr = i2c->addr; xfer[0].flags = 0; xfer[0].len = 1; xfer[0].buf = (void *)&txdata; xfer[1].addr = i2c->addr; xfer[1].flags = I2C_M_RD; xfer[1].len = 2; xfer[1].buf = (void *)rxdata; ret = i2c_transfer(i2c->adapter, xfer, 2); if (ret < 0) return ret; if (ret != 2) return -EIO; /* * Byte 0 is transfer length, which is always 1 due * to BCP register programming to 1 in si521xx_probe(), * ignore it and use data from Byte 1. */ *val = rxdata[1]; return 0; } static const struct regmap_config si521xx_regmap_config = { .reg_bits = 8, .val_bits = 8, .cache_type = REGCACHE_FLAT, .max_register = SI521XX_REG_DA, .rd_table = &si521xx_readable_table, .wr_table = &si521xx_writeable_table, .reg_write = si521xx_regmap_i2c_write, .reg_read = si521xx_regmap_i2c_read, }; static unsigned long si521xx_diff_recalc_rate(struct clk_hw *hw, unsigned long parent_rate) { unsigned long long rate; rate = (unsigned long long)parent_rate * SI521XX_DIFF_MULT; do_div(rate, SI521XX_DIFF_DIV); return (unsigned long)rate; } static long si521xx_diff_round_rate(struct clk_hw *hw, unsigned long rate, unsigned long *prate) { unsigned long best_parent; best_parent = (rate / SI521XX_DIFF_MULT) * SI521XX_DIFF_DIV; *prate = clk_hw_round_rate(clk_hw_get_parent(hw), best_parent); return (*prate / SI521XX_DIFF_DIV) * SI521XX_DIFF_MULT; } static int si521xx_diff_set_rate(struct clk_hw *hw, unsigned long rate, unsigned long parent_rate) { /* * We must report success but we can do so unconditionally because * si521xx_diff_round_rate returns values that ensure this call is a * nop. */ return 0; } #define to_si521xx_clk(_hw) container_of(_hw, struct si_clk, hw) static int si521xx_diff_prepare(struct clk_hw *hw) { struct si_clk *si_clk = to_si521xx_clk(hw); struct si521xx *si = si_clk->si; regmap_set_bits(si->regmap, SI521XX_REG_OE(si_clk->reg), si_clk->bit); return 0; } static void si521xx_diff_unprepare(struct clk_hw *hw) { struct si_clk *si_clk = to_si521xx_clk(hw); struct si521xx *si = si_clk->si; regmap_clear_bits(si->regmap, SI521XX_REG_OE(si_clk->reg), si_clk->bit); } static const struct clk_ops si521xx_diff_clk_ops = { .round_rate = si521xx_diff_round_rate, .set_rate = si521xx_diff_set_rate, .recalc_rate = si521xx_diff_recalc_rate, .prepare = si521xx_diff_prepare, .unprepare = si521xx_diff_unprepare, }; static int si521xx_get_common_config(struct si521xx *si) { struct i2c_client *client = si->client; struct device_node *np = client->dev.of_node; unsigned int amp; int ret; /* Set defaults */ si->pll_amplitude = SI521XX_REG_DA_AMP(SI521XX_REG_DA_AMP_DEFAULT); /* Output clock amplitude */ ret = of_property_read_u32(np, "skyworks,out-amplitude-microvolt", &); if (!ret) { if (amp < SI521XX_REG_DA_AMP_MIN || amp > SI521XX_REG_DA_AMP_MAX || amp % SI521XX_REG_DA_AMP_STEP) { return dev_err_probe(&client->dev, -EINVAL, "Invalid skyworks,out-amplitude-microvolt value\n"); } si->pll_amplitude = SI521XX_REG_DA_AMP(amp); } return 0; } static void si521xx_update_config(struct si521xx *si) { /* If amplitude is non-default, update it. */ if (si->pll_amplitude == SI521XX_REG_DA_AMP(SI521XX_REG_DA_AMP_DEFAULT)) return; regmap_update_bits(si->regmap, SI521XX_REG_DA, SI521XX_REG_DA_AMP_MASK, si->pll_amplitude); } static void si521xx_diff_idx_to_reg_bit(const u16 chip_info, const int idx, struct si_clk *clk) { unsigned long mask; int oe, b, ctr = 0; for (oe = 1; oe <= 2; oe++) { mask = bitrev8(SI521XX_OE_MAP_GET_OE(oe, chip_info)); for_each_set_bit(b, &mask, 8) { if (ctr++ != idx) continue; clk->reg = SI521XX_REG_OE(oe); clk->bit = 7 - b; return; } } } static struct clk_hw * si521xx_of_clk_get(struct of_phandle_args *clkspec, void *data) { struct si521xx *si = data; unsigned int idx = clkspec->args[0]; return &si->clk_dif[idx].hw; } static int si521xx_probe(struct i2c_client *client) { const u16 chip_info = (u16)(uintptr_t)i2c_get_match_data(client); const struct clk_parent_data clk_parent_data = { .index = 0 }; const u8 data[3] = { SI521XX_REG_BC, 1, 1 }; unsigned char name[16] = "DIFF0"; struct clk_init_data init = {}; struct si521xx *si; int i, ret; if (!chip_info) return -EINVAL; si = devm_kzalloc(&client->dev, sizeof(*si), GFP_KERNEL); if (!si) return -ENOMEM; i2c_set_clientdata(client, si); si->client = client; /* Fetch common configuration from DT (if specified) */ ret = si521xx_get_common_config(si); if (ret) return ret; si->regmap = devm_regmap_init(&client->dev, NULL, client, &si521xx_regmap_config); if (IS_ERR(si->regmap)) return dev_err_probe(&client->dev, PTR_ERR(si->regmap), "Failed to allocate register map\n"); /* Always read back 1 Byte via I2C */ ret = i2c_master_send(client, data, ARRAY_SIZE(data)); if (ret < 0) return ret; /* Register clock */ for (i = 0; i < hweight16(chip_info); i++) { memset(&init, 0, sizeof(init)); snprintf(name, sizeof(name), "DIFF%d", i); init.name = name; init.ops = &si521xx_diff_clk_ops; init.parent_data = &clk_parent_data; init.num_parents = 1; init.flags = CLK_SET_RATE_PARENT; si->clk_dif[i].hw.init = &init; si->clk_dif[i].si = si; si521xx_diff_idx_to_reg_bit(chip_info, i, &si->clk_dif[i]); ret = devm_clk_hw_register(&client->dev, &si->clk_dif[i].hw); if (ret) return ret; } ret = devm_of_clk_add_hw_provider(&client->dev, si521xx_of_clk_get, si); if (!ret) si521xx_update_config(si); return ret; } static int __maybe_unused si521xx_suspend(struct device *dev) { struct si521xx *si = dev_get_drvdata(dev); regcache_cache_only(si->regmap, true); regcache_mark_dirty(si->regmap); return 0; } static int __maybe_unused si521xx_resume(struct device *dev) { struct si521xx *si = dev_get_drvdata(dev); int ret; regcache_cache_only(si->regmap, false); ret = regcache_sync(si->regmap); if (ret) dev_err(dev, "Failed to restore register map: %d\n", ret); return ret; } static const struct i2c_device_id si521xx_id[] = { { "si52144", .driver_data = SI521XX_OE_MAP(0x5, 0xc0) }, { "si52146", .driver_data = SI521XX_OE_MAP(0x15, 0xe0) }, { "si52147", .driver_data = SI521XX_OE_MAP(0x17, 0xf8) }, { } }; MODULE_DEVICE_TABLE(i2c, si521xx_id); static const struct of_device_id clk_si521xx_of_match[] = { { .compatible = "skyworks,si52144", .data = (void *)SI521XX_OE_MAP(0x5, 0xc0) }, { .compatible = "skyworks,si52146", .data = (void *)SI521XX_OE_MAP(0x15, 0xe0) }, { .compatible = "skyworks,si52147", .data = (void *)SI521XX_OE_MAP(0x15, 0xf8) }, { } }; MODULE_DEVICE_TABLE(of, clk_si521xx_of_match); static SIMPLE_DEV_PM_OPS(si521xx_pm_ops, si521xx_suspend, si521xx_resume); static struct i2c_driver si521xx_driver = { .driver = { .name = "clk-si521xx", .pm = &si521xx_pm_ops, .of_match_table = clk_si521xx_of_match, }, .probe = si521xx_probe, .id_table = si521xx_id, }; module_i2c_driver(si521xx_driver); MODULE_AUTHOR("Marek Vasut "); MODULE_DESCRIPTION("Skyworks Si521xx PCIe clock generator driver"); MODULE_LICENSE("GPL");