// SPDX-License-Identifier: GPL-2.0-or-later /* * Driver for Renesas 9-series PCIe clock generator driver * * The following series can be supported: * - 9FGV/9DBV/9DMV/9FGL/9DML/9QXL/9SQ * Currently supported: * - 9FGV0241 * - 9FGV0441 * * Copyright (C) 2022 Marek Vasut */ #include #include #include #include #include #include #define RS9_REG_OE 0x0 #define RS9_REG_SS 0x1 #define RS9_REG_SS_AMP_0V6 0x0 #define RS9_REG_SS_AMP_0V7 0x1 #define RS9_REG_SS_AMP_0V8 0x2 #define RS9_REG_SS_AMP_0V9 0x3 #define RS9_REG_SS_AMP_MASK 0x3 #define RS9_REG_SS_SSC_100 0 #define RS9_REG_SS_SSC_M025 (1 << 3) #define RS9_REG_SS_SSC_M050 (3 << 3) #define RS9_REG_SS_SSC_MASK (3 << 3) #define RS9_REG_SS_SSC_LOCK BIT(5) #define RS9_REG_SR 0x2 #define RS9_REG_REF 0x3 #define RS9_REG_REF_OE BIT(4) #define RS9_REG_REF_OD BIT(5) #define RS9_REG_REF_SR_SLOWEST 0 #define RS9_REG_REF_SR_SLOW (1 << 6) #define RS9_REG_REF_SR_FAST (2 << 6) #define RS9_REG_REF_SR_FASTER (3 << 6) #define RS9_REG_VID 0x5 #define RS9_REG_DID 0x6 #define RS9_REG_BCP 0x7 #define RS9_REG_VID_IDT 0x01 #define RS9_REG_DID_TYPE_FGV (0x0 << RS9_REG_DID_TYPE_SHIFT) #define RS9_REG_DID_TYPE_DBV (0x1 << RS9_REG_DID_TYPE_SHIFT) #define RS9_REG_DID_TYPE_DMV (0x2 << RS9_REG_DID_TYPE_SHIFT) #define RS9_REG_DID_TYPE_SHIFT 0x6 /* Supported Renesas 9-series models. */ enum rs9_model { RENESAS_9FGV0241, RENESAS_9FGV0441, }; /* Structure to describe features of a particular 9-series model */ struct rs9_chip_info { const enum rs9_model model; unsigned int num_clks; u8 did; }; struct rs9_driver_data { struct i2c_client *client; struct regmap *regmap; const struct rs9_chip_info *chip_info; struct clk_hw *clk_dif[4]; u8 pll_amplitude; u8 pll_ssc; u8 clk_dif_sr; }; /* * Renesas 9-series i2c regmap */ static const struct regmap_range rs9_readable_ranges[] = { regmap_reg_range(RS9_REG_OE, RS9_REG_REF), regmap_reg_range(RS9_REG_VID, RS9_REG_BCP), }; static const struct regmap_access_table rs9_readable_table = { .yes_ranges = rs9_readable_ranges, .n_yes_ranges = ARRAY_SIZE(rs9_readable_ranges), }; static const struct regmap_range rs9_writeable_ranges[] = { regmap_reg_range(RS9_REG_OE, RS9_REG_REF), regmap_reg_range(RS9_REG_BCP, RS9_REG_BCP), }; static const struct regmap_access_table rs9_writeable_table = { .yes_ranges = rs9_writeable_ranges, .n_yes_ranges = ARRAY_SIZE(rs9_writeable_ranges), }; static int rs9_regmap_i2c_write(void *context, unsigned int reg, unsigned int val) { struct i2c_client *i2c = context; const u8 data[3] = { reg, 1, 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 rs9_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 rs9_probe(), * ignore it and use data from Byte 1. */ *val = rxdata[1]; return 0; } static const struct regmap_config rs9_regmap_config = { .reg_bits = 8, .val_bits = 8, .cache_type = REGCACHE_NONE, .max_register = RS9_REG_BCP, .rd_table = &rs9_readable_table, .wr_table = &rs9_writeable_table, .reg_write = rs9_regmap_i2c_write, .reg_read = rs9_regmap_i2c_read, }; static u8 rs9_calc_dif(const struct rs9_driver_data *rs9, int idx) { enum rs9_model model = rs9->chip_info->model; if (model == RENESAS_9FGV0241) return BIT(idx) + 1; else if (model == RENESAS_9FGV0441) return BIT(idx); return 0; } static int rs9_get_output_config(struct rs9_driver_data *rs9, int idx) { struct i2c_client *client = rs9->client; u8 dif = rs9_calc_dif(rs9, idx); unsigned char name[5] = "DIF0"; struct device_node *np; int ret; u32 sr; /* Set defaults */ rs9->clk_dif_sr |= dif; snprintf(name, 5, "DIF%d", idx); np = of_get_child_by_name(client->dev.of_node, name); if (!np) return 0; /* Output clock slew rate */ ret = of_property_read_u32(np, "renesas,slew-rate", &sr); of_node_put(np); if (!ret) { if (sr == 2000000) { /* 2V/ns */ rs9->clk_dif_sr &= ~dif; } else if (sr == 3000000) { /* 3V/ns (default) */ rs9->clk_dif_sr |= dif; } else ret = dev_err_probe(&client->dev, -EINVAL, "Invalid renesas,slew-rate value\n"); } return ret; } static int rs9_get_common_config(struct rs9_driver_data *rs9) { struct i2c_client *client = rs9->client; struct device_node *np = client->dev.of_node; unsigned int amp, ssc; int ret; /* Set defaults */ rs9->pll_amplitude = RS9_REG_SS_AMP_0V7; rs9->pll_ssc = RS9_REG_SS_SSC_100; /* Output clock amplitude */ ret = of_property_read_u32(np, "renesas,out-amplitude-microvolt", &); if (!ret) { if (amp == 600000) /* 0.6V */ rs9->pll_amplitude = RS9_REG_SS_AMP_0V6; else if (amp == 700000) /* 0.7V (default) */ rs9->pll_amplitude = RS9_REG_SS_AMP_0V7; else if (amp == 800000) /* 0.8V */ rs9->pll_amplitude = RS9_REG_SS_AMP_0V8; else if (amp == 900000) /* 0.9V */ rs9->pll_amplitude = RS9_REG_SS_AMP_0V9; else return dev_err_probe(&client->dev, -EINVAL, "Invalid renesas,out-amplitude-microvolt value\n"); } /* Output clock spread spectrum */ ret = of_property_read_u32(np, "renesas,out-spread-spectrum", &ssc); if (!ret) { if (ssc == 100000) /* 100% ... no spread (default) */ rs9->pll_ssc = RS9_REG_SS_SSC_100; else if (ssc == 99750) /* -0.25% ... down spread */ rs9->pll_ssc = RS9_REG_SS_SSC_M025; else if (ssc == 99500) /* -0.50% ... down spread */ rs9->pll_ssc = RS9_REG_SS_SSC_M050; else return dev_err_probe(&client->dev, -EINVAL, "Invalid renesas,out-spread-spectrum value\n"); } return 0; } static void rs9_update_config(struct rs9_driver_data *rs9) { int i; /* If amplitude is non-default, update it. */ if (rs9->pll_amplitude != RS9_REG_SS_AMP_0V7) { regmap_update_bits(rs9->regmap, RS9_REG_SS, RS9_REG_SS_AMP_MASK, rs9->pll_amplitude); } /* If SSC is non-default, update it. */ if (rs9->pll_ssc != RS9_REG_SS_SSC_100) { regmap_update_bits(rs9->regmap, RS9_REG_SS, RS9_REG_SS_SSC_MASK, rs9->pll_ssc); } for (i = 0; i < rs9->chip_info->num_clks; i++) { u8 dif = rs9_calc_dif(rs9, i); if (rs9->clk_dif_sr & dif) continue; regmap_update_bits(rs9->regmap, RS9_REG_SR, dif, rs9->clk_dif_sr & dif); } } static struct clk_hw * rs9_of_clk_get(struct of_phandle_args *clkspec, void *data) { struct rs9_driver_data *rs9 = data; unsigned int idx = clkspec->args[0]; return rs9->clk_dif[idx]; } static int rs9_probe(struct i2c_client *client) { unsigned char name[5] = "DIF0"; struct rs9_driver_data *rs9; unsigned int vid, did; struct clk_hw *hw; int i, ret; rs9 = devm_kzalloc(&client->dev, sizeof(*rs9), GFP_KERNEL); if (!rs9) return -ENOMEM; i2c_set_clientdata(client, rs9); rs9->client = client; rs9->chip_info = device_get_match_data(&client->dev); if (!rs9->chip_info) return -EINVAL; /* Fetch common configuration from DT (if specified) */ ret = rs9_get_common_config(rs9); if (ret) return ret; /* Fetch DIFx output configuration from DT (if specified) */ for (i = 0; i < rs9->chip_info->num_clks; i++) { ret = rs9_get_output_config(rs9, i); if (ret) return ret; } rs9->regmap = devm_regmap_init(&client->dev, NULL, client, &rs9_regmap_config); if (IS_ERR(rs9->regmap)) return dev_err_probe(&client->dev, PTR_ERR(rs9->regmap), "Failed to allocate register map\n"); /* Always read back 1 Byte via I2C */ ret = regmap_write(rs9->regmap, RS9_REG_BCP, 1); if (ret < 0) return ret; ret = regmap_read(rs9->regmap, RS9_REG_VID, &vid); if (ret < 0) return ret; ret = regmap_read(rs9->regmap, RS9_REG_DID, &did); if (ret < 0) return ret; if (vid != RS9_REG_VID_IDT || did != rs9->chip_info->did) return dev_err_probe(&client->dev, -ENODEV, "Incorrect VID/DID: %#02x, %#02x. Expected %#02x, %#02x\n", vid, did, RS9_REG_VID_IDT, rs9->chip_info->did); /* Register clock */ for (i = 0; i < rs9->chip_info->num_clks; i++) { snprintf(name, 5, "DIF%d", i); hw = devm_clk_hw_register_fixed_factor_index(&client->dev, name, 0, 0, 4, 1); if (IS_ERR(hw)) return PTR_ERR(hw); rs9->clk_dif[i] = hw; } ret = devm_of_clk_add_hw_provider(&client->dev, rs9_of_clk_get, rs9); if (!ret) rs9_update_config(rs9); return ret; } static int __maybe_unused rs9_suspend(struct device *dev) { struct rs9_driver_data *rs9 = dev_get_drvdata(dev); regcache_cache_only(rs9->regmap, true); regcache_mark_dirty(rs9->regmap); return 0; } static int __maybe_unused rs9_resume(struct device *dev) { struct rs9_driver_data *rs9 = dev_get_drvdata(dev); int ret; regcache_cache_only(rs9->regmap, false); ret = regcache_sync(rs9->regmap); if (ret) dev_err(dev, "Failed to restore register map: %d\n", ret); return ret; } static const struct rs9_chip_info renesas_9fgv0241_info = { .model = RENESAS_9FGV0241, .num_clks = 2, .did = RS9_REG_DID_TYPE_FGV | 0x02, }; static const struct rs9_chip_info renesas_9fgv0441_info = { .model = RENESAS_9FGV0441, .num_clks = 4, .did = RS9_REG_DID_TYPE_FGV | 0x04, }; static const struct i2c_device_id rs9_id[] = { { "9fgv0241", .driver_data = RENESAS_9FGV0241 }, { "9fgv0441", .driver_data = RENESAS_9FGV0441 }, { } }; MODULE_DEVICE_TABLE(i2c, rs9_id); static const struct of_device_id clk_rs9_of_match[] = { { .compatible = "renesas,9fgv0241", .data = &renesas_9fgv0241_info }, { .compatible = "renesas,9fgv0441", .data = &renesas_9fgv0441_info }, { } }; MODULE_DEVICE_TABLE(of, clk_rs9_of_match); static SIMPLE_DEV_PM_OPS(rs9_pm_ops, rs9_suspend, rs9_resume); static struct i2c_driver rs9_driver = { .driver = { .name = "clk-renesas-pcie-9series", .pm = &rs9_pm_ops, .of_match_table = clk_rs9_of_match, }, .probe_new = rs9_probe, .id_table = rs9_id, }; module_i2c_driver(rs9_driver); MODULE_AUTHOR("Marek Vasut "); MODULE_DESCRIPTION("Renesas 9-series PCIe clock generator driver"); MODULE_LICENSE("GPL");