| Message ID | 20201208012615.2717412-2-andrew@aj.id.au |
|---|---|
| State | New |
| Headers | show |
| Series | mmc: sdhci-of-aspeed: Expose phase delay tuning | expand |
On Tue, 15 Dec 2020, at 02:18, Ulf Hansson wrote: > On Tue, 8 Dec 2020 at 02:26, Andrew Jeffery <andrew@aj.id.au> wrote: > > > > Drivers for MMC hosts that accept phase corrections can take advantage > > of the helper by embedding a mmc_clk_phase_map_t object 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 <andrew@aj.id.au> > > --- > > drivers/mmc/core/host.c | 44 ++++++++++++++++++++++++++++++++++++++++ > > include/linux/mmc/host.h | 17 ++++++++++++++++ > > 2 files changed, 61 insertions(+) > > > > diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c > > index 96b2ca1f1b06..b1697f00c4b5 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, mmc_clk_phase_map_t map) > > Would you mind to change to pass a "struct mmc_clk_phase_map *map" to this? > > See more comments below. > > > +{ > > + struct device *dev = host->parent; > > + > > + mmc_of_parse_timing_phase(dev, "clk-phase-legacy", > > + &map[MMC_TIMING_LEGACY]); > > + mmc_of_parse_timing_phase(dev, "clk-phase-mmc-hs", > > + &map[MMC_TIMING_MMC_HS]); > > + mmc_of_parse_timing_phase(dev, "clk-phase-sd-hs", > > + &map[MMC_TIMING_SD_HS]); > > + mmc_of_parse_timing_phase(dev, "clk-phase-uhs-sdr12", > > + &map[MMC_TIMING_UHS_SDR12]); > > + mmc_of_parse_timing_phase(dev, "clk-phase-uhs-sdr25", > > + &map[MMC_TIMING_UHS_SDR25]); > > + mmc_of_parse_timing_phase(dev, "clk-phase-uhs-sdr50", > > + &map[MMC_TIMING_UHS_SDR50]); > > + mmc_of_parse_timing_phase(dev, "clk-phase-uhs-sdr104", > > + &map[MMC_TIMING_UHS_SDR104]); > > + mmc_of_parse_timing_phase(dev, "clk-phase-uhs-ddr50", > > + &map[MMC_TIMING_UHS_DDR50]); > > + mmc_of_parse_timing_phase(dev, "clk-phase-mmc-ddr52", > > + &map[MMC_TIMING_MMC_DDR52]); > > + mmc_of_parse_timing_phase(dev, "clk-phase-mmc-hs200", > > + &map[MMC_TIMING_MMC_HS200]); > > + mmc_of_parse_timing_phase(dev, "clk-phase-mmc-hs400", > > + &map[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..bc4731c9738f 100644 > > --- a/include/linux/mmc/host.h > > +++ b/include/linux/mmc/host.h > > @@ -79,6 +79,22 @@ struct mmc_ios { > > bool enhanced_strobe; /* hs400es selection */ > > }; > > > > +struct mmc_clk_phase { > > + bool valid; > > + u16 in_deg; > > + u16 out_deg; > > +}; > > + > > +/* > > + * Define a type to map between bus timings and phase correction values. To > > + * avoid bloat in struct mmc_host we leave it to the host driver to define the > > + * phase map object in its private data if it supports phase correction. > > + * However, mmc_of_parse_clk_phase() is provided by the mmc core and needs the > > + * provided array to be correctly sized, so typedef an appropriately sized > > + * array to minimise the chance that the wrong size object is passed. > > + */ > > +typedef struct mmc_clk_phase mmc_clk_phase_map_t[MMC_TIMING_MMC_HS400 + 1]; > > + > > Nitpick: I would appreciate if we could avoid using "typedefs", as I > think they in many cases makes the code harder to read. How about > doing this instead? > > #define MMC_NUM_CLK_PHASES (MMC_TIMING_MMC_HS400 + 1) > > struct mmc_clk_phase_map { > struct mmc_clk_phase phase[MMC_NUM_CLK_PHASES]; > }; > > [...] Right; I experimented with that approach and felt it was kinda clunky (hence the typedef), but I'll respin the series doing as such. Thanks, Andrew
diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c index 96b2ca1f1b06..b1697f00c4b5 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, mmc_clk_phase_map_t map) +{ + struct device *dev = host->parent; + + mmc_of_parse_timing_phase(dev, "clk-phase-legacy", + &map[MMC_TIMING_LEGACY]); + mmc_of_parse_timing_phase(dev, "clk-phase-mmc-hs", + &map[MMC_TIMING_MMC_HS]); + mmc_of_parse_timing_phase(dev, "clk-phase-sd-hs", + &map[MMC_TIMING_SD_HS]); + mmc_of_parse_timing_phase(dev, "clk-phase-uhs-sdr12", + &map[MMC_TIMING_UHS_SDR12]); + mmc_of_parse_timing_phase(dev, "clk-phase-uhs-sdr25", + &map[MMC_TIMING_UHS_SDR25]); + mmc_of_parse_timing_phase(dev, "clk-phase-uhs-sdr50", + &map[MMC_TIMING_UHS_SDR50]); + mmc_of_parse_timing_phase(dev, "clk-phase-uhs-sdr104", + &map[MMC_TIMING_UHS_SDR104]); + mmc_of_parse_timing_phase(dev, "clk-phase-uhs-ddr50", + &map[MMC_TIMING_UHS_DDR50]); + mmc_of_parse_timing_phase(dev, "clk-phase-mmc-ddr52", + &map[MMC_TIMING_MMC_DDR52]); + mmc_of_parse_timing_phase(dev, "clk-phase-mmc-hs200", + &map[MMC_TIMING_MMC_HS200]); + mmc_of_parse_timing_phase(dev, "clk-phase-mmc-hs400", + &map[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..bc4731c9738f 100644 --- a/include/linux/mmc/host.h +++ b/include/linux/mmc/host.h @@ -79,6 +79,22 @@ struct mmc_ios { bool enhanced_strobe; /* hs400es selection */ }; +struct mmc_clk_phase { + bool valid; + u16 in_deg; + u16 out_deg; +}; + +/* + * Define a type to map between bus timings and phase correction values. To + * avoid bloat in struct mmc_host we leave it to the host driver to define the + * phase map object in its private data if it supports phase correction. + * However, mmc_of_parse_clk_phase() is provided by the mmc core and needs the + * provided array to be correctly sized, so typedef an appropriately sized + * array to minimise the chance that the wrong size object is passed. + */ +typedef struct mmc_clk_phase mmc_clk_phase_map_t[MMC_TIMING_MMC_HS400 + 1]; + struct mmc_host; struct mmc_host_ops { @@ -490,6 +506,7 @@ 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, mmc_clk_phase_map_t map); int mmc_of_parse(struct mmc_host *host); int mmc_of_parse_voltage(struct device_node *np, u32 *mask);
Drivers for MMC hosts that accept phase corrections can take advantage of the helper by embedding a mmc_clk_phase_map_t object 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 <andrew@aj.id.au> --- drivers/mmc/core/host.c | 44 ++++++++++++++++++++++++++++++++++++++++ include/linux/mmc/host.h | 17 ++++++++++++++++ 2 files changed, 61 insertions(+)