From 9fe69429509858d9db6ae123c4cb078351ec2623 Mon Sep 17 00:00:00 2001 From: Robert Jarzmik Date: Wed, 2 Nov 2016 22:33:06 +0100 Subject: clk: pxa: transfer CPU clock setting from pxa2xx-cpufreq This is the initial stage to transfer the pxa25x and pxa27x CPU clocks handling from cpufreq to the clock API. More precisely, the clocks transferred are : - cpll : core pll, known also as the CPU core turbo frequency - core : core, known also as the CPU actual frequency, being either the CPU core turbo frequency or the CPU core run frequency This transfer is a prequel to shrink the code in pxa2xx-cpufreq.c, so that it can become, at least in devicetree builds, the casual cpufreq-dt driver. Signed-off-by: Robert Jarzmik Signed-off-by: Stephen Boyd --- drivers/clk/pxa/clk-pxa.c | 139 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 139 insertions(+) (limited to 'drivers/clk/pxa/clk-pxa.c') diff --git a/drivers/clk/pxa/clk-pxa.c b/drivers/clk/pxa/clk-pxa.c index 29cee9e8d4d9..50fb9d0ea58d 100644 --- a/drivers/clk/pxa/clk-pxa.c +++ b/drivers/clk/pxa/clk-pxa.c @@ -18,6 +18,26 @@ #include #include "clk-pxa.h" +#define KHz 1000 +#define MHz (1000 * 1000) + +#define MDREFR_K0DB4 (1 << 29) /* SDCLK0 Divide by 4 Control/Status */ +#define MDREFR_K2FREE (1 << 25) /* SDRAM Free-Running Control */ +#define MDREFR_K1FREE (1 << 24) /* SDRAM Free-Running Control */ +#define MDREFR_K0FREE (1 << 23) /* SDRAM Free-Running Control */ +#define MDREFR_SLFRSH (1 << 22) /* SDRAM Self-Refresh Control/Status */ +#define MDREFR_APD (1 << 20) /* SDRAM/SSRAM Auto-Power-Down Enable */ +#define MDREFR_K2DB2 (1 << 19) /* SDCLK2 Divide by 2 Control/Status */ +#define MDREFR_K2RUN (1 << 18) /* SDCLK2 Run Control/Status */ +#define MDREFR_K1DB2 (1 << 17) /* SDCLK1 Divide by 2 Control/Status */ +#define MDREFR_K1RUN (1 << 16) /* SDCLK1 Run Control/Status */ +#define MDREFR_E1PIN (1 << 15) /* SDCKE1 Level Control/Status */ +#define MDREFR_K0DB2 (1 << 14) /* SDCLK0 Divide by 2 Control/Status */ +#define MDREFR_K0RUN (1 << 13) /* SDCLK0 Run Control/Status */ +#define MDREFR_E0PIN (1 << 12) /* SDCKE0 Level Control/Status */ +#define MDREFR_DB2_MASK (MDREFR_K2DB2 | MDREFR_K1DB2) +#define MDREFR_DRI_MASK 0xFFF + DEFINE_SPINLOCK(lock); static struct clk *pxa_clocks[CLK_MAX]; @@ -106,3 +126,122 @@ void __init clk_pxa_dt_common_init(struct device_node *np) { of_clk_add_provider(np, of_clk_src_onecell_get, &onecell_data); } + +void pxa2xx_core_turbo_switch(bool on) +{ + unsigned long flags; + unsigned int unused, clkcfg; + + local_irq_save(flags); + + asm("mrc p14, 0, %0, c6, c0, 0" : "=r" (clkcfg)); + clkcfg &= ~CLKCFG_TURBO & ~CLKCFG_HALFTURBO; + if (on) + clkcfg |= CLKCFG_TURBO; + clkcfg |= CLKCFG_FCS; + + asm volatile( + " b 2f\n" + " .align 5\n" + "1: mcr p14, 0, %1, c6, c0, 0\n" + " b 3f\n" + "2: b 1b\n" + "3: nop\n" + : "=&r" (unused) + : "r" (clkcfg) + : ); + + local_irq_restore(flags); +} + +void pxa2xx_cpll_change(struct pxa2xx_freq *freq, + u32 (*mdrefr_dri)(unsigned int), u32 *mdrefr, u32 *cccr) +{ + unsigned int clkcfg = freq->clkcfg; + unsigned int unused, preset_mdrefr, postset_mdrefr; + unsigned long flags; + + local_irq_save(flags); + + /* Calculate the next MDREFR. If we're slowing down the SDRAM clock + * we need to preset the smaller DRI before the change. If we're + * speeding up we need to set the larger DRI value after the change. + */ + preset_mdrefr = postset_mdrefr = readl(mdrefr); + if ((preset_mdrefr & MDREFR_DRI_MASK) > mdrefr_dri(freq->membus_khz)) { + preset_mdrefr = (preset_mdrefr & ~MDREFR_DRI_MASK); + preset_mdrefr |= mdrefr_dri(freq->membus_khz); + } + postset_mdrefr = + (postset_mdrefr & ~MDREFR_DRI_MASK) | + mdrefr_dri(freq->membus_khz); + + /* If we're dividing the memory clock by two for the SDRAM clock, this + * must be set prior to the change. Clearing the divide must be done + * after the change. + */ + if (freq->div2) { + preset_mdrefr |= MDREFR_DB2_MASK; + postset_mdrefr |= MDREFR_DB2_MASK; + } else { + postset_mdrefr &= ~MDREFR_DB2_MASK; + } + + /* Set new the CCCR and prepare CLKCFG */ + writel(freq->cccr, cccr); + + asm volatile( + " ldr r4, [%1]\n" + " b 2f\n" + " .align 5\n" + "1: str %3, [%1] /* preset the MDREFR */\n" + " mcr p14, 0, %2, c6, c0, 0 /* set CLKCFG[FCS] */\n" + " str %4, [%1] /* postset the MDREFR */\n" + " b 3f\n" + "2: b 1b\n" + "3: nop\n" + : "=&r" (unused) + : "r" (mdrefr), "r" (clkcfg), "r" (preset_mdrefr), + "r" (postset_mdrefr) + : "r4", "r5"); + + local_irq_restore(flags); +} + +int pxa2xx_determine_rate(struct clk_rate_request *req, + struct pxa2xx_freq *freqs, int nb_freqs) +{ + int i, closest_below = -1, closest_above = -1, ret = 0; + unsigned long rate; + + for (i = 0; i < nb_freqs; i++) { + rate = freqs[i].cpll; + if (rate == req->rate) + break; + if (rate < req->min_rate) + continue; + if (rate > req->max_rate) + continue; + if (rate <= req->rate) + closest_below = i; + if ((rate >= req->rate) && (closest_above == -1)) + closest_above = i; + } + + req->best_parent_hw = NULL; + + if (i < nb_freqs) + ret = 0; + else if (closest_below >= 0) + rate = freqs[closest_below].cpll; + else if (closest_above >= 0) + rate = freqs[closest_above].cpll; + else + ret = -EINVAL; + + pr_debug("%s(rate=%lu) rate=%lu: %d\n", __func__, req->rate, rate, ret); + if (!rate) + req->rate = rate; + + return ret; +} -- cgit v1.2.3-55-g7522