diff options
Diffstat (limited to 'drivers/clk/pxa/clk-pxa.c')
| -rw-r--r-- | drivers/clk/pxa/clk-pxa.c | 247 |
1 files changed, 247 insertions, 0 deletions
diff --git a/drivers/clk/pxa/clk-pxa.c b/drivers/clk/pxa/clk-pxa.c new file mode 100644 index 000000000..b80dc9d58 --- /dev/null +++ b/drivers/clk/pxa/clk-pxa.c @@ -0,0 +1,247 @@ +/* + * Marvell PXA family clocks + * + * Copyright (C) 2014 Robert Jarzmik + * + * Common clock code for PXA clocks ("CKEN" type clocks + DT) + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; version 2 of the License. + * + */ +#include <linux/clk.h> +#include <linux/clk-provider.h> +#include <linux/clkdev.h> +#include <linux/of.h> + +#include <dt-bindings/clock/pxa-clock.h> +#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 + +static DEFINE_SPINLOCK(pxa_clk_lock); + +static struct clk *pxa_clocks[CLK_MAX]; +static struct clk_onecell_data onecell_data = { + .clks = pxa_clocks, + .clk_num = CLK_MAX, +}; + +struct pxa_clk { + struct clk_hw hw; + struct clk_fixed_factor lp; + struct clk_fixed_factor hp; + struct clk_gate gate; + bool (*is_in_low_power)(void); +}; + +#define to_pxa_clk(_hw) container_of(_hw, struct pxa_clk, hw) + +static unsigned long cken_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct pxa_clk *pclk = to_pxa_clk(hw); + struct clk_fixed_factor *fix; + + if (!pclk->is_in_low_power || pclk->is_in_low_power()) + fix = &pclk->lp; + else + fix = &pclk->hp; + __clk_hw_set_clk(&fix->hw, hw); + return clk_fixed_factor_ops.recalc_rate(&fix->hw, parent_rate); +} + +static struct clk_ops cken_rate_ops = { + .recalc_rate = cken_recalc_rate, +}; + +static u8 cken_get_parent(struct clk_hw *hw) +{ + struct pxa_clk *pclk = to_pxa_clk(hw); + + if (!pclk->is_in_low_power) + return 0; + return pclk->is_in_low_power() ? 0 : 1; +} + +static struct clk_ops cken_mux_ops = { + .get_parent = cken_get_parent, + .set_parent = dummy_clk_set_parent, +}; + +void __init clkdev_pxa_register(int ckid, const char *con_id, + const char *dev_id, struct clk *clk) +{ + if (!IS_ERR(clk) && (ckid != CLK_NONE)) + pxa_clocks[ckid] = clk; + if (!IS_ERR(clk)) + clk_register_clkdev(clk, con_id, dev_id); +} + +int __init clk_pxa_cken_init(const struct desc_clk_cken *clks, int nb_clks) +{ + int i; + struct pxa_clk *pxa_clk; + struct clk *clk; + + for (i = 0; i < nb_clks; i++) { + pxa_clk = kzalloc(sizeof(*pxa_clk), GFP_KERNEL); + pxa_clk->is_in_low_power = clks[i].is_in_low_power; + pxa_clk->lp = clks[i].lp; + pxa_clk->hp = clks[i].hp; + pxa_clk->gate = clks[i].gate; + pxa_clk->gate.lock = &pxa_clk_lock; + clk = clk_register_composite(NULL, clks[i].name, + clks[i].parent_names, 2, + &pxa_clk->hw, &cken_mux_ops, + &pxa_clk->hw, &cken_rate_ops, + &pxa_clk->gate.hw, &clk_gate_ops, + clks[i].flags); + clkdev_pxa_register(clks[i].ckid, clks[i].con_id, + clks[i].dev_id, clk); + } + return 0; +} + +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), void __iomem *mdrefr, + void __iomem *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; + 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) { + rate = req->rate; + } else if (closest_below >= 0) { + rate = freqs[closest_below].cpll; + } else if (closest_above >= 0) { + rate = freqs[closest_above].cpll; + } else { + pr_debug("%s(rate=%lu) no match\n", __func__, req->rate); + return -EINVAL; + } + + pr_debug("%s(rate=%lu) rate=%lu\n", __func__, req->rate, rate); + req->rate = rate; + + return 0; +} |