From 3561afa02605b398d1b98e1ce913ea6411cdc5dd Mon Sep 17 00:00:00 2001 From: Andrew Jeffery Date: Thu, 14 Jan 2021 13:44:28 +1030 Subject: [PATCH] mmc: core: Add helper for parsing clock phase properties Drivers for MMC hosts that accept phase corrections can take advantage of the helper by embedding an instance of struct mmc_clk_phase_map in their private data and invoking mmc_of_parse_clk_phase() to extract phase parameters. It is the responsibility of the host driver to translate and apply the extracted values to hardware as required. Signed-off-by: Andrew Jeffery Link: https://lore.kernel.org/r/20210114031433.2388532-2-andrew@aj.id.au Signed-off-by: Ulf Hansson --- drivers/mmc/core/host.c | 44 ++++++++++++++++++++++++++++++++++++++++ include/linux/mmc/host.h | 13 ++++++++++++ 2 files changed, 57 insertions(+) diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c index 96b2ca1f1b06..74e853bb6948 100644 --- a/drivers/mmc/core/host.c +++ b/drivers/mmc/core/host.c @@ -163,6 +163,50 @@ static void mmc_retune_timer(struct timer_list *t) mmc_retune_needed(host); } +static void mmc_of_parse_timing_phase(struct device *dev, const char *prop, + struct mmc_clk_phase *phase) +{ + int degrees[2] = {0}; + int rc; + + rc = device_property_read_u32_array(dev, prop, degrees, 2); + phase->valid = !rc; + if (phase->valid) { + phase->in_deg = degrees[0]; + phase->out_deg = degrees[1]; + } +} + +void +mmc_of_parse_clk_phase(struct mmc_host *host, struct mmc_clk_phase_map *map) +{ + struct device *dev = host->parent; + + mmc_of_parse_timing_phase(dev, "clk-phase-legacy", + &map->phase[MMC_TIMING_LEGACY]); + mmc_of_parse_timing_phase(dev, "clk-phase-mmc-hs", + &map->phase[MMC_TIMING_MMC_HS]); + mmc_of_parse_timing_phase(dev, "clk-phase-sd-hs", + &map->phase[MMC_TIMING_SD_HS]); + mmc_of_parse_timing_phase(dev, "clk-phase-uhs-sdr12", + &map->phase[MMC_TIMING_UHS_SDR12]); + mmc_of_parse_timing_phase(dev, "clk-phase-uhs-sdr25", + &map->phase[MMC_TIMING_UHS_SDR25]); + mmc_of_parse_timing_phase(dev, "clk-phase-uhs-sdr50", + &map->phase[MMC_TIMING_UHS_SDR50]); + mmc_of_parse_timing_phase(dev, "clk-phase-uhs-sdr104", + &map->phase[MMC_TIMING_UHS_SDR104]); + mmc_of_parse_timing_phase(dev, "clk-phase-uhs-ddr50", + &map->phase[MMC_TIMING_UHS_DDR50]); + mmc_of_parse_timing_phase(dev, "clk-phase-mmc-ddr52", + &map->phase[MMC_TIMING_MMC_DDR52]); + mmc_of_parse_timing_phase(dev, "clk-phase-mmc-hs200", + &map->phase[MMC_TIMING_MMC_HS200]); + mmc_of_parse_timing_phase(dev, "clk-phase-mmc-hs400", + &map->phase[MMC_TIMING_MMC_HS400]); +} +EXPORT_SYMBOL(mmc_of_parse_clk_phase); + /** * mmc_of_parse() - parse host's device-tree node * @host: host whose node should be parsed. diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h index 01bba36545c5..8cf686d98a68 100644 --- a/include/linux/mmc/host.h +++ b/include/linux/mmc/host.h @@ -79,6 +79,17 @@ struct mmc_ios { bool enhanced_strobe; /* hs400es selection */ }; +struct mmc_clk_phase { + bool valid; + u16 in_deg; + u16 out_deg; +}; + +#define MMC_NUM_CLK_PHASES (MMC_TIMING_MMC_HS400 + 1) +struct mmc_clk_phase_map { + struct mmc_clk_phase phase[MMC_NUM_CLK_PHASES]; +}; + struct mmc_host; struct mmc_host_ops { @@ -490,6 +501,8 @@ struct mmc_host *mmc_alloc_host(int extra, struct device *); int mmc_add_host(struct mmc_host *); void mmc_remove_host(struct mmc_host *); void mmc_free_host(struct mmc_host *); +void mmc_of_parse_clk_phase(struct mmc_host *host, + struct mmc_clk_phase_map *map); int mmc_of_parse(struct mmc_host *host); int mmc_of_parse_voltage(struct device_node *np, u32 *mask); -- 2.25.1