diff options
Diffstat (limited to 'arch/arm/mach-omap2/clkt34xx_dpll3m2.c')
| -rw-r--r-- | arch/arm/mach-omap2/clkt34xx_dpll3m2.c | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/arch/arm/mach-omap2/clkt34xx_dpll3m2.c b/arch/arm/mach-omap2/clkt34xx_dpll3m2.c new file mode 100644 index 00000000000..8716a01d1f5 --- /dev/null +++ b/arch/arm/mach-omap2/clkt34xx_dpll3m2.c @@ -0,0 +1,120 @@ +/* + * OMAP34xx M2 divider clock code + * + * Copyright (C) 2007-2008 Texas Instruments, Inc. + * Copyright (C) 2007-2010 Nokia Corporation + * + * Paul Walmsley + * Jouni Högander + * + * Parts of this code are based on code written by + * Richard Woodruff, Tony Lindgren, Tuukka Tikkanen, Karthik Dasu + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#undef DEBUG + +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/clk.h> +#include <linux/io.h> + +#include <plat/clock.h> +#include <plat/sram.h> +#include <plat/sdrc.h> + +#include "clock.h" +#include "clock34xx.h" +#include "sdrc.h" + +#define CYCLES_PER_MHZ 1000000 + +/* + * CORE DPLL (DPLL3) M2 divider rate programming functions + * + * These call into SRAM code to do the actual CM writes, since the SDRAM + * is clocked from DPLL3. + */ + +/** + * omap3_core_dpll_m2_set_rate - set CORE DPLL M2 divider + * @clk: struct clk * of DPLL to set + * @rate: rounded target rate + * + * Program the DPLL M2 divider with the rounded target rate. Returns + * -EINVAL upon error, or 0 upon success. + */ +int omap3_core_dpll_m2_set_rate(struct clk *clk, unsigned long rate) +{ + u32 new_div = 0; + u32 unlock_dll = 0; + u32 c; + unsigned long validrate, sdrcrate, _mpurate; + struct omap_sdrc_params *sdrc_cs0; + struct omap_sdrc_params *sdrc_cs1; + int ret; + + if (!clk || !rate) + return -EINVAL; + + validrate = omap2_clksel_round_rate_div(clk, rate, &new_div); + if (validrate != rate) + return -EINVAL; + + sdrcrate = sdrc_ick_p->rate; + if (rate > clk->rate) + sdrcrate <<= ((rate / clk->rate) >> 1); + else + sdrcrate >>= ((clk->rate / rate) >> 1); + + ret = omap2_sdrc_get_params(sdrcrate, &sdrc_cs0, &sdrc_cs1); + if (ret) + return -EINVAL; + + if (sdrcrate < MIN_SDRC_DLL_LOCK_FREQ) { + pr_debug("clock: will unlock SDRC DLL\n"); + unlock_dll = 1; + } + + /* + * XXX This only needs to be done when the CPU frequency changes + */ + _mpurate = arm_fck_p->rate / CYCLES_PER_MHZ; + c = (_mpurate << SDRC_MPURATE_SCALE) >> SDRC_MPURATE_BASE_SHIFT; + c += 1; /* for safety */ + c *= SDRC_MPURATE_LOOPS; + c >>= SDRC_MPURATE_SCALE; + if (c == 0) + c = 1; + + pr_debug("clock: changing CORE DPLL rate from %lu to %lu\n", clk->rate, + validrate); + pr_debug("clock: SDRC CS0 timing params used:" + " RFR %08x CTRLA %08x CTRLB %08x MR %08x\n", + sdrc_cs0->rfr_ctrl, sdrc_cs0->actim_ctrla, + sdrc_cs0->actim_ctrlb, sdrc_cs0->mr); + if (sdrc_cs1) + pr_debug("clock: SDRC CS1 timing params used: " + " RFR %08x CTRLA %08x CTRLB %08x MR %08x\n", + sdrc_cs1->rfr_ctrl, sdrc_cs1->actim_ctrla, + sdrc_cs1->actim_ctrlb, sdrc_cs1->mr); + + if (sdrc_cs1) + omap3_configure_core_dpll( + new_div, unlock_dll, c, rate > clk->rate, + sdrc_cs0->rfr_ctrl, sdrc_cs0->actim_ctrla, + sdrc_cs0->actim_ctrlb, sdrc_cs0->mr, + sdrc_cs1->rfr_ctrl, sdrc_cs1->actim_ctrla, + sdrc_cs1->actim_ctrlb, sdrc_cs1->mr); + else + omap3_configure_core_dpll( + new_div, unlock_dll, c, rate > clk->rate, + sdrc_cs0->rfr_ctrl, sdrc_cs0->actim_ctrla, + sdrc_cs0->actim_ctrlb, sdrc_cs0->mr, + 0, 0, 0, 0); + + return 0; +} + |