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Fix fractional divider calculations and round down for sdmmc clocks.

This commit is contained in:
jmcneill 2017-04-22 17:40:47 +00:00
parent c1cbf1992b
commit 22b9f6b21a
1 changed files with 32 additions and 4 deletions
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36
sys/arch/arm/nvidia/tegra124_car.c
View File

@ -1,4 +1,4 @@
/* $NetBSD: tegra124_car.c,v 1.10 2017/04/16 12:28:21 jmcneill Exp $ */
/* $NetBSD: tegra124_car.c,v 1.11 2017/04/22 17:40:47 jmcneill Exp $ */
/*-
* Copyright (c) 2015 Jared D. McNeill <jmcneill@invisible.ca>
@ -27,7 +27,7 @@
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: tegra124_car.c,v 1.10 2017/04/16 12:28:21 jmcneill Exp $");
__KERNEL_RCSID(0, "$NetBSD: tegra124_car.c,v 1.11 2017/04/22 17:40:47 jmcneill Exp $");
#include <sys/param.h>
#include <sys/bus.h>
@ -1203,6 +1203,16 @@ tegra124_car_clock_get_rate_fixed_div(struct tegra124_car_softc *sc,
return parent_rate / tfixed_div->div;
}
static u_int
tegra124_car_clock_calc_rate_frac_div(u_int rate, u_int raw_div)
{
raw_div += 2;
rate *= 2;
rate += raw_div - 1;
rate /= raw_div;
return rate;
}
static u_int
tegra124_car_clock_get_rate_div(struct tegra124_car_softc *sc,
struct tegra_clk *tclk)
@ -1235,13 +1245,15 @@ tegra124_car_clock_get_rate_div(struct tegra124_car_softc *sc,
case CAR_CLKSRC_UARTC_REG:
case CAR_CLKSRC_UARTD_REG:
if (v & CAR_CLKSRC_UART_DIV_ENB) {
rate = parent_rate * 2 / (raw_div + 2);
rate = tegra124_car_clock_calc_rate_frac_div(
parent_rate, raw_div);
} else {
rate = parent_rate;
}
break;
default:
rate = parent_rate * 2 / (raw_div + 2);
rate = tegra124_car_clock_calc_rate_frac_div(parent_rate,
raw_div);
break;
}
@ -1301,6 +1313,22 @@ tegra124_car_clock_set_rate_div(struct tegra124_car_softc *sc,
if (rate)
raw_div = parent_rate / rate - 1;
break;
case CAR_CLKSRC_SDMMC1_REG:
case CAR_CLKSRC_SDMMC2_REG:
case CAR_CLKSRC_SDMMC3_REG:
case CAR_CLKSRC_SDMMC4_REG:
if (rate) {
for (raw_div = 0x00; raw_div <= 0xff; raw_div++) {
u_int calc_rate =
tegra124_car_clock_calc_rate_frac_div(
parent_rate, raw_div);
if (calc_rate <= rate)
break;
}
if (raw_div == 0x100)
return EINVAL;
}
break;
default:
if (rate)
raw_div = (parent_rate * 2) / rate - 2;