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i2c: sh_mobile: Switch R-Mobile A1/APE6 and SH-Mobile AG5 to new frequency calculation

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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>
This commit is contained in:
Geert Uytterhoeven 2024-01-31 17:09:30 +01:00 committed by Andi Shyti
parent c0fcc4d9fc
commit 7a7fd335f8
1 changed files with 11 additions and 16 deletions
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27
drivers/i2c/busses/i2c-sh_mobile.c
View File

@ -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 = {
@ -782,11 +782,6 @@ 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 },
{},
};