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| author | Geert Uytterhoeven <geert+renesas@glider.be> | 2024-01-31 17:09:30 +0100 |
|---|---|---|
| committer | Andi Shyti <andi.shyti@kernel.org> | 2024-02-08 09:34:17 +0100 |
| commit | 7a7fd335f821f93f9327f581e1677361c48a0dea (patch) | |
| tree | 18f0513916a2b6041863a4a57565d315a3632bf2 /drivers/i2c/busses | |
| parent | c0fcc4d9fc0784f8c11af0343092f8d945339431 (diff) | |
| download | lwn-7a7fd335f821f93f9327f581e1677361c48a0dea.tar.gz lwn-7a7fd335f821f93f9327f581e1677361c48a0dea.zip | |
i2c: sh_mobile: Switch R-Mobile A1/APE6 and SH-Mobile AG5 to new frequency calculation
Switch the R-Mobile A1, R-Mobile APE6, and SH-Mobile AG5 SoCs to the new
frequency calculation formula, to (a) avoid running the I2C bus too fast,
and (b) bring the low/high ratio closer to the recommended ratio 5/4.
As this makes fast_clock_dt_config and v2_freq_calc_dt_config identical,
merge them into a single fast_clock_dt_config.
Legacy SH users (sh7343, sh7366, and sh772[234]) are left alone, and
still use the old formula.
Measurement results on R-Mobile APE6 and SH-Mobile AG5 (fck=104 MHz,
clks_per_count=2):
100 kHz: 106 kHz LH=1.12 before, 99.6 kHz L/H=1.22 after
400 kHz: 384 kHz LH=1.67 before, 392 kHz L/H=1.27 after
Measurement results on R-Mobile A1 (fck=49.5 MHz, clks_per_count=1):
100 kHz: 106 kHz L/H=1.09 before, 99.6 kHz L/H=1.20 after
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Diffstat (limited to 'drivers/i2c/busses')
| -rw-r--r-- | drivers/i2c/busses/i2c-sh_mobile.c | 27 |
1 files changed, 11 insertions, 16 deletions
diff --git a/drivers/i2c/busses/i2c-sh_mobile.c b/drivers/i2c/busses/i2c-sh_mobile.c index 5adbe62cf621..c65ac3d7eadc 100644 --- a/drivers/i2c/busses/i2c-sh_mobile.c +++ b/drivers/i2c/busses/i2c-sh_mobile.c @@ -773,7 +773,7 @@ static int sh_mobile_i2c_r8a7740_workaround(struct sh_mobile_i2c_data *pd) iic_wr(pd, ICCR, ICCR_TRS); udelay(10); - return sh_mobile_i2c_init(pd); + return sh_mobile_i2c_v2_init(pd); } static const struct sh_mobile_dt_config default_dt_config = { @@ -783,11 +783,6 @@ static const struct sh_mobile_dt_config default_dt_config = { static const struct sh_mobile_dt_config fast_clock_dt_config = { .clks_per_count = 2, - .setup = sh_mobile_i2c_init, -}; - -static const struct sh_mobile_dt_config v2_freq_calc_dt_config = { - .clks_per_count = 2, .setup = sh_mobile_i2c_v2_init, }; @@ -799,17 +794,17 @@ static const struct sh_mobile_dt_config r8a7740_dt_config = { static const struct of_device_id sh_mobile_i2c_dt_ids[] = { { .compatible = "renesas,iic-r8a73a4", .data = &fast_clock_dt_config }, { .compatible = "renesas,iic-r8a7740", .data = &r8a7740_dt_config }, - { .compatible = "renesas,iic-r8a774c0", .data = &v2_freq_calc_dt_config }, - { .compatible = "renesas,iic-r8a7790", .data = &v2_freq_calc_dt_config }, - { .compatible = "renesas,iic-r8a7791", .data = &v2_freq_calc_dt_config }, - { .compatible = "renesas,iic-r8a7792", .data = &v2_freq_calc_dt_config }, - { .compatible = "renesas,iic-r8a7793", .data = &v2_freq_calc_dt_config }, - { .compatible = "renesas,iic-r8a7794", .data = &v2_freq_calc_dt_config }, - { .compatible = "renesas,iic-r8a7795", .data = &v2_freq_calc_dt_config }, - { .compatible = "renesas,iic-r8a77990", .data = &v2_freq_calc_dt_config }, + { .compatible = "renesas,iic-r8a774c0", .data = &fast_clock_dt_config }, + { .compatible = "renesas,iic-r8a7790", .data = &fast_clock_dt_config }, + { .compatible = "renesas,iic-r8a7791", .data = &fast_clock_dt_config }, + { .compatible = "renesas,iic-r8a7792", .data = &fast_clock_dt_config }, + { .compatible = "renesas,iic-r8a7793", .data = &fast_clock_dt_config }, + { .compatible = "renesas,iic-r8a7794", .data = &fast_clock_dt_config }, + { .compatible = "renesas,iic-r8a7795", .data = &fast_clock_dt_config }, + { .compatible = "renesas,iic-r8a77990", .data = &fast_clock_dt_config }, { .compatible = "renesas,iic-sh73a0", .data = &fast_clock_dt_config }, - { .compatible = "renesas,rcar-gen2-iic", .data = &v2_freq_calc_dt_config }, - { .compatible = "renesas,rcar-gen3-iic", .data = &v2_freq_calc_dt_config }, + { .compatible = "renesas,rcar-gen2-iic", .data = &fast_clock_dt_config }, + { .compatible = "renesas,rcar-gen3-iic", .data = &fast_clock_dt_config }, { .compatible = "renesas,rmobile-iic", .data = &default_dt_config }, {}, }; |