diff options
Diffstat (limited to 'drivers/clk/clk-renesas-pcie.c')
| -rw-r--r-- | drivers/clk/clk-renesas-pcie.c | 381 |
1 files changed, 381 insertions, 0 deletions
diff --git a/drivers/clk/clk-renesas-pcie.c b/drivers/clk/clk-renesas-pcie.c new file mode 100644 index 000000000000..e6247141d0c0 --- /dev/null +++ b/drivers/clk/clk-renesas-pcie.c @@ -0,0 +1,381 @@ +// 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 + * + * Copyright (C) 2022 Marek Vasut <marex@denx.de> + */ + +#include <linux/clk-provider.h> +#include <linux/i2c.h> +#include <linux/mod_devicetable.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/regmap.h> + +#define RS9_REG_OE 0x0 +#define RS9_REG_OE_DIF_OE(n) BIT((n) + 1) +#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_SR_2V0_DIF(n) 0 +#define RS9_REG_SR_3V0_DIF(n) BIT((n) + 1) +#define RS9_REG_SR_DIF_MASK(n) BIT((n) + 1) +#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 + +/* Supported Renesas 9-series models. */ +enum rs9_model { + RENESAS_9FGV0241, +}; + +/* Structure to describe features of a particular 9-series model */ +struct rs9_chip_info { + const enum rs9_model model; + unsigned int num_clks; +}; + +struct rs9_driver_data { + struct i2c_client *client; + struct regmap *regmap; + const struct rs9_chip_info *chip_info; + struct clk *pin_xin; + struct clk_hw *clk_dif[2]; + 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 int rs9_get_output_config(struct rs9_driver_data *rs9, int idx) +{ + struct i2c_client *client = rs9->client; + unsigned char name[5] = "DIF0"; + struct device_node *np; + int ret; + u32 sr; + + /* Set defaults */ + rs9->clk_dif_sr &= ~RS9_REG_SR_DIF_MASK(idx); + rs9->clk_dif_sr |= RS9_REG_SR_3V0_DIF(idx); + + 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 &= ~RS9_REG_SR_DIF_MASK(idx); + rs9->clk_dif_sr |= RS9_REG_SR_2V0_DIF(idx); + } else if (sr == 3000000) { /* 3V/ns (default) */ + rs9->clk_dif_sr &= ~RS9_REG_SR_DIF_MASK(idx); + rs9->clk_dif_sr |= RS9_REG_SR_3V0_DIF(idx); + } 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++) { + if (rs9->clk_dif_sr & RS9_REG_SR_3V0_DIF(i)) + continue; + + regmap_update_bits(rs9->regmap, RS9_REG_SR, RS9_REG_SR_3V0_DIF(i), + rs9->clk_dif_sr & RS9_REG_SR_3V0_DIF(i)); + } +} + +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; + 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; + + /* 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, +}; + +static const struct i2c_device_id rs9_id[] = { + { "9fgv0241", .driver_data = RENESAS_9FGV0241 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, rs9_id); + +static const struct of_device_id clk_rs9_of_match[] = { + { .compatible = "renesas,9fgv0241", .data = &renesas_9fgv0241_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 <marex@denx.de>"); +MODULE_DESCRIPTION("Renesas 9-series PCIe clock generator driver"); +MODULE_LICENSE("GPL"); |