diff options
Diffstat (limited to 'arch/arm/mach-omap2/clkt2xxx_apll.c')
-rw-r--r-- | arch/arm/mach-omap2/clkt2xxx_apll.c | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/arch/arm/mach-omap2/clkt2xxx_apll.c b/arch/arm/mach-omap2/clkt2xxx_apll.c new file mode 100644 index 000000000000..fc32ff8e790f --- /dev/null +++ b/arch/arm/mach-omap2/clkt2xxx_apll.c @@ -0,0 +1,120 @@ +/* + * OMAP2xxx APLL clock control functions + * + * Copyright (C) 2005-2008 Texas Instruments, Inc. + * Copyright (C) 2004-2010 Nokia Corporation + * + * Contacts: + * Richard Woodruff <r-woodruff2@ti.com> + * Paul Walmsley + * + * Based on earlier work by Tuukka Tikkanen, Tony Lindgren, + * Gordon McNutt and RidgeRun, Inc. + * + * 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/clk.h> +#include <linux/io.h> + +#include <plat/clock.h> +#include <plat/prcm.h> + +#include "clock.h" +#include "clock2xxx.h" +#include "cm.h" +#include "cm-regbits-24xx.h" + +/* CM_CLKEN_PLL.EN_{54,96}M_PLL options (24XX) */ +#define EN_APLL_STOPPED 0 +#define EN_APLL_LOCKED 3 + +/* CM_CLKSEL1_PLL.APLLS_CLKIN options (24XX) */ +#define APLLS_CLKIN_19_2MHZ 0 +#define APLLS_CLKIN_13MHZ 2 +#define APLLS_CLKIN_12MHZ 3 + +/* Private functions */ + +/* Enable an APLL if off */ +static int omap2_clk_apll_enable(struct clk *clk, u32 status_mask) +{ + u32 cval, apll_mask; + + apll_mask = EN_APLL_LOCKED << clk->enable_bit; + + cval = cm_read_mod_reg(PLL_MOD, CM_CLKEN); + + if ((cval & apll_mask) == apll_mask) + return 0; /* apll already enabled */ + + cval &= ~apll_mask; + cval |= apll_mask; + cm_write_mod_reg(cval, PLL_MOD, CM_CLKEN); + + omap2_cm_wait_idlest(OMAP_CM_REGADDR(PLL_MOD, CM_IDLEST), status_mask, + clk->name); + + /* + * REVISIT: Should we return an error code if omap2_wait_clock_ready() + * fails? + */ + return 0; +} + +static int omap2_clk_apll96_enable(struct clk *clk) +{ + return omap2_clk_apll_enable(clk, OMAP24XX_ST_96M_APLL); +} + +static int omap2_clk_apll54_enable(struct clk *clk) +{ + return omap2_clk_apll_enable(clk, OMAP24XX_ST_54M_APLL); +} + +/* Stop APLL */ +static void omap2_clk_apll_disable(struct clk *clk) +{ + u32 cval; + + cval = cm_read_mod_reg(PLL_MOD, CM_CLKEN); + cval &= ~(EN_APLL_LOCKED << clk->enable_bit); + cm_write_mod_reg(cval, PLL_MOD, CM_CLKEN); +} + +/* Public data */ + +const struct clkops clkops_apll96 = { + .enable = omap2_clk_apll96_enable, + .disable = omap2_clk_apll_disable, +}; + +const struct clkops clkops_apll54 = { + .enable = omap2_clk_apll54_enable, + .disable = omap2_clk_apll_disable, +}; + +/* Public functions */ + +u32 omap2xxx_get_apll_clkin(void) +{ + u32 aplls, srate = 0; + + aplls = cm_read_mod_reg(PLL_MOD, CM_CLKSEL1); + aplls &= OMAP24XX_APLLS_CLKIN_MASK; + aplls >>= OMAP24XX_APLLS_CLKIN_SHIFT; + + if (aplls == APLLS_CLKIN_19_2MHZ) + srate = 19200000; + else if (aplls == APLLS_CLKIN_13MHZ) + srate = 13000000; + else if (aplls == APLLS_CLKIN_12MHZ) + srate = 12000000; + + return srate; +} + |