This is the driver for the main PLL clock hardware found on DM SoCs. This driver borrowed code from arch/arm/mach-davinci/clock.c and implemented the driver as per common clock provider API. The main PLL hardware typically has a multiplier, a pre-divider and a post-divider. Some of the SoCs has the divider fixed meaning they can not be configured through a register. HAS_PREDIV and HAS_POSTDIV flags are used to tell the driver if a hardware has these dividers present or not. Driver is configured through the structure clk_davinci_pll_data that has the platform data for the driver.
Signed-off-by: Murali Karicheri <[email protected]> diff --git a/drivers/clk/davinci/clk-davinci-pll.c b/drivers/clk/davinci/clk-davinci-pll.c new file mode 100644 index 0000000..13e1690 --- /dev/null +++ b/drivers/clk/davinci/clk-davinci-pll.c @@ -0,0 +1,128 @@ +/* + * PLL clk driver DaVinci devices + * + * Copyright (C) 2006-2012 Texas Instruments. + * Copyright (C) 2008-2009 Deep Root Systems, LLC + * + * 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; either version 2 of the License, or + * (at your option) any later version. + * TODO - Add set_parent_rate() + */ +#include <linux/clk.h> +#include <linux/clk-provider.h> +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/io.h> +#include <linux/slab.h> +#include <linux/platform_data/clk-davinci-pll.h> + +#include <mach/cputype.h> + +#define PLLM 0x110 +#define PLLM_PLLM_MASK 0xff +#define PREDIV 0x114 +#define POSTDIV 0x128 +#define PLLDIV_EN BIT(15) + +/** + * struct clk_davinci_pll - DaVinci Main pll clock + * @hw: clk_hw for the pll + * @pll_data: PLL driver specific data + */ +struct clk_davinci_pll { + struct clk_hw hw; + struct clk_davinci_pll_data *pll_data; +}; + +#define to_clk_pll(_hw) container_of(_hw, struct clk_davinci_pll, hw) + +static unsigned long clk_pllclk_recalc(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct clk_davinci_pll *pll = to_clk_pll(hw); + struct clk_davinci_pll_data *pll_data = pll->pll_data; + u32 mult = 1, prediv = 1, postdiv = 1; + unsigned long rate = parent_rate; + + /* If there is a device specific recalc defined invoke it. Otherwise + * fallback to default one + */ + mult = __raw_readl(pll_data->pllm); + if (pll_data->pllm_multiplier) + mult = pll_data->pllm_multiplier * + (mult & pll_data->pllm_mask); + else + mult = (mult & pll_data->pllm_mask) + 1; + + if (pll_data->flags & CLK_DAVINCI_PLL_HAS_PREDIV) { + /* pre-divider is fixed, take prediv value from pll_data */ + if (pll_data->fixed_prediv) + prediv = pll_data->fixed_prediv; + else { + prediv = __raw_readl(pll_data->prediv); + if (prediv & PLLDIV_EN) + prediv = (prediv & pll_data->prediv_mask) + 1; + else + prediv = 1; + } + } + + if (pll_data->flags & CLK_DAVINCI_PLL_HAS_POSTDIV) { + postdiv = __raw_readl(pll_data->postdiv); + if (postdiv & PLLDIV_EN) + postdiv = (postdiv & pll_data->postdiv_mask) + 1; + else + postdiv = 1; + } + + rate /= prediv; + rate *= mult; + rate /= postdiv; + + pr_debug("PLL%d: input = %lu MHz [ ", + pll_data->num, parent_rate / 1000000); + if (prediv > 1) + pr_debug("/ %d ", prediv); + if (mult > 1) + pr_debug("* %d ", mult); + if (postdiv > 1) + pr_debug("/ %d ", postdiv); + pr_debug("] --> %lu MHz output.\n", rate / 1000000); + return rate; +} + +static const struct clk_ops clk_pll_ops = { + .recalc_rate = clk_pllclk_recalc, +}; + +struct clk *clk_register_davinci_pll(struct device *dev, const char *name, + const char *parent_name, + struct clk_davinci_pll_data *pll_data) +{ + struct clk_init_data init; + struct clk_davinci_pll *pll; + struct clk *clk; + + if (!pll_data) + return ERR_PTR(-ENODEV); + + pll = kzalloc(sizeof(*pll), GFP_KERNEL); + if (!pll) + return ERR_PTR(-ENOMEM); + init.name = name; + init.ops = &clk_pll_ops; + init.flags = pll_data->flags; + init.parent_names = (parent_name ? &parent_name : NULL); + init.num_parents = (parent_name ? 1 : 0); + + pll->pll_data = pll_data; + pll->hw.init = &init; + + clk = clk_register(NULL, &pll->hw); + if (IS_ERR(clk)) + kfree(pll); + + return clk; +} diff --git a/include/linux/platform_data/clk-davinci-pll.h b/include/linux/platform_data/clk-davinci-pll.h new file mode 100644 index 0000000..69d44ab --- /dev/null +++ b/include/linux/platform_data/clk-davinci-pll.h @@ -0,0 +1,52 @@ +/* + * TI DaVinci clk-pll driver platform data definitions + * + * Copyright (C) 2006-2012 Texas Instruments. + * Copyright (C) 2008-2009 Deep Root Systems, LLC + * + * 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. + * + * This program is distributed "as is" WITHOUT ANY WARRANTY of any + * kind, whether express or implied; without even the implied warranty + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ +#ifndef __CLK_DAVINCI_PLL_H +#define __CLK_DAVINCI_PLL_H + +/* PLL flags */ +#define CLK_DAVINCI_PLL_HAS_PREDIV BIT(0) +#define CLK_DAVINCI_PLL_HAS_POSTDIV BIT(1) + +struct clk_davinci_pll_data { + /* physical addresses set by platform code */ + u32 phy_pllm; + /* if PLL has a prediv register this should be non zero */ + u32 phy_prediv; + /* if PLL has a postdiv register this should be non zero */ + u32 phy_postdiv; + /* mapped addresses. should be initialized by */ + void __iomem *pllm; + void __iomem *prediv; + void __iomem *postdiv; + u32 pllm_mask; + u32 prediv_mask; + u32 postdiv_mask; + u32 num; + /* framework flags */ + u32 flags; + /* pll flags */ + u32 pll_flags; + u32 fixed_prediv; /* use this value for prediv */ + u32 pllm_multiplier; /* multiply PLLM by this factor. By default + * most SOC set this to zero that translates + * to a multiplier of 1 and incrementer of 1. + * To override default, set this factor */ +}; + +extern struct clk *clk_register_davinci_pll(struct device *dev, + const char *name, const char *parent_name, + struct clk_davinci_pll_data *pll_data); +#endif /* CLK_DAVINCI_PLL_H */ -- 1.7.9.5 _______________________________________________ Davinci-linux-open-source mailing list [email protected] http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
