diff options
Diffstat (limited to 'drivers/mmc/host/dw_mmc-starfive.c')
| -rw-r--r-- | drivers/mmc/host/dw_mmc-starfive.c | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/drivers/mmc/host/dw_mmc-starfive.c b/drivers/mmc/host/dw_mmc-starfive.c new file mode 100644 index 0000000000..fd05a648a8 --- /dev/null +++ b/drivers/mmc/host/dw_mmc-starfive.c @@ -0,0 +1,186 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * StarFive Designware Mobile Storage Host Controller Driver + * + * Copyright (c) 2022 StarFive Technology Co., Ltd. + */ + +#include <linux/clk.h> +#include <linux/delay.h> +#include <linux/mfd/syscon.h> +#include <linux/mmc/host.h> +#include <linux/module.h> +#include <linux/of_address.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> + +#include "dw_mmc.h" +#include "dw_mmc-pltfm.h" + +#define ALL_INT_CLR 0x1ffff +#define MAX_DELAY_CHAIN 32 + +struct starfive_priv { + struct device *dev; + struct regmap *reg_syscon; + u32 syscon_offset; + u32 syscon_shift; + u32 syscon_mask; +}; + +static void dw_mci_starfive_set_ios(struct dw_mci *host, struct mmc_ios *ios) +{ + int ret; + unsigned int clock; + + if (ios->timing == MMC_TIMING_MMC_DDR52 || ios->timing == MMC_TIMING_UHS_DDR50) { + clock = (ios->clock > 50000000 && ios->clock <= 52000000) ? 100000000 : ios->clock; + ret = clk_set_rate(host->ciu_clk, clock); + if (ret) + dev_dbg(host->dev, "Use an external frequency divider %uHz\n", ios->clock); + host->bus_hz = clk_get_rate(host->ciu_clk); + } else { + dev_dbg(host->dev, "Using the internal divider\n"); + } +} + +static int dw_mci_starfive_execute_tuning(struct dw_mci_slot *slot, + u32 opcode) +{ + static const int grade = MAX_DELAY_CHAIN; + struct dw_mci *host = slot->host; + struct starfive_priv *priv = host->priv; + int rise_point = -1, fall_point = -1; + int err, prev_err = 0; + int i; + bool found = 0; + u32 regval; + + /* + * Use grade as the max delay chain, and use the rise_point and + * fall_point to ensure the best sampling point of a data input + * signals. + */ + for (i = 0; i < grade; i++) { + regval = i << priv->syscon_shift; + err = regmap_update_bits(priv->reg_syscon, priv->syscon_offset, + priv->syscon_mask, regval); + if (err) + return err; + mci_writel(host, RINTSTS, ALL_INT_CLR); + + err = mmc_send_tuning(slot->mmc, opcode, NULL); + if (!err) + found = 1; + + if (i > 0) { + if (err && !prev_err) + fall_point = i - 1; + if (!err && prev_err) + rise_point = i; + } + + if (rise_point != -1 && fall_point != -1) + goto tuning_out; + + prev_err = err; + err = 0; + } + +tuning_out: + if (found) { + if (rise_point == -1) + rise_point = 0; + if (fall_point == -1) + fall_point = grade - 1; + if (fall_point < rise_point) { + if ((rise_point + fall_point) > + (grade - 1)) + i = fall_point / 2; + else + i = (rise_point + grade - 1) / 2; + } else { + i = (rise_point + fall_point) / 2; + } + + regval = i << priv->syscon_shift; + err = regmap_update_bits(priv->reg_syscon, priv->syscon_offset, + priv->syscon_mask, regval); + if (err) + return err; + mci_writel(host, RINTSTS, ALL_INT_CLR); + + dev_info(host->dev, "Found valid delay chain! use it [delay=%d]\n", i); + } else { + dev_err(host->dev, "No valid delay chain! use default\n"); + err = -EINVAL; + } + + mci_writel(host, RINTSTS, ALL_INT_CLR); + return err; +} + +static int dw_mci_starfive_parse_dt(struct dw_mci *host) +{ + struct of_phandle_args args; + struct starfive_priv *priv; + int ret; + + priv = devm_kzalloc(host->dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + ret = of_parse_phandle_with_fixed_args(host->dev->of_node, + "starfive,sysreg", 3, 0, &args); + if (ret) { + dev_err(host->dev, "Failed to parse starfive,sysreg\n"); + return -EINVAL; + } + + priv->reg_syscon = syscon_node_to_regmap(args.np); + of_node_put(args.np); + if (IS_ERR(priv->reg_syscon)) + return PTR_ERR(priv->reg_syscon); + + priv->syscon_offset = args.args[0]; + priv->syscon_shift = args.args[1]; + priv->syscon_mask = args.args[2]; + + host->priv = priv; + + return 0; +} + +static const struct dw_mci_drv_data starfive_data = { + .common_caps = MMC_CAP_CMD23, + .set_ios = dw_mci_starfive_set_ios, + .parse_dt = dw_mci_starfive_parse_dt, + .execute_tuning = dw_mci_starfive_execute_tuning, +}; + +static const struct of_device_id dw_mci_starfive_match[] = { + { .compatible = "starfive,jh7110-mmc", + .data = &starfive_data }, + {}, +}; +MODULE_DEVICE_TABLE(of, dw_mci_starfive_match); + +static int dw_mci_starfive_probe(struct platform_device *pdev) +{ + return dw_mci_pltfm_register(pdev, &starfive_data); +} + +static struct platform_driver dw_mci_starfive_driver = { + .probe = dw_mci_starfive_probe, + .remove_new = dw_mci_pltfm_remove, + .driver = { + .name = "dwmmc_starfive", + .probe_type = PROBE_PREFER_ASYNCHRONOUS, + .of_match_table = dw_mci_starfive_match, + }, +}; +module_platform_driver(dw_mci_starfive_driver); + +MODULE_DESCRIPTION("StarFive JH7110 Specific DW-MSHC Driver Extension"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:dwmmc_starfive"); |