Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 308964ca authored by Loc Ho's avatar Loc Ho Committed by Mike Turquette
Browse files

clk: Add APM X-Gene SoC clock driver 



clk: Add APM X-Gene SoC clock driver for reference, PLL, and device clocks.

Signed-off-by: default avatarLoc Ho <lho@apm.com>
Signed-off-by: default avatarKumar Sankaran <ksankaran@apm.com>
Signed-off-by: default avatarVinayak Kale <vkale@apm.com>
Signed-off-by: default avatarFeng Kan <fkan@apm.com>
Signed-off-by: default avatarMike Turquette <mturquette@linaro.org>
parent 92947789

drivers/clk/Kconfig

+7 −0
Original line number Original line Diff line number Diff line
@@ -93,6 +93,13 @@ config CLK_PPC_CORENET 
	  This adds the clock driver support for Freescale PowerPC corenet

	  This adds the clock driver support for Freescale PowerPC corenet

	  platforms using common clock framework.

	  platforms using common clock framework.





config COMMON_CLK_XGENE

	bool "Clock driver for APM XGene SoC"

	default y

	depends on ARM64

	---help---

	  Sypport for the APM X-Gene SoC reference, PLL, and device clocks.



endmenu

endmenu





source "drivers/clk/mvebu/Kconfig"
 
source "drivers/clk/mvebu/Kconfig"

drivers/clk/Makefile

+1 −0
Original line number Original line Diff line number Diff line
@@ -32,6 +32,7 @@ obj-$(CONFIG_ARCH_VT8500) += clk-vt8500.o 
obj-$(CONFIG_ARCH_ZYNQ)		+= zynq/

obj-$(CONFIG_ARCH_ZYNQ)		+= zynq/

obj-$(CONFIG_ARCH_TEGRA)	+= tegra/

obj-$(CONFIG_ARCH_TEGRA)	+= tegra/

obj-$(CONFIG_PLAT_SAMSUNG)	+= samsung/

obj-$(CONFIG_PLAT_SAMSUNG)	+= samsung/

obj-$(CONFIG_COMMON_CLK_XGENE)  += clk-xgene.o





obj-$(CONFIG_X86)		+= x86/

obj-$(CONFIG_X86)		+= x86/

drivers/clk/clk-xgene.c

0 → 100644
+521 −0
Original line number Original line Diff line number Diff line 
/*

 * clk-xgene.c - AppliedMicro X-Gene Clock Interface

 *

 * Copyright (c) 2013, Applied Micro Circuits Corporation

 * Author: Loc Ho <lho@apm.com>

 *

 * 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.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,

 * MA 02111-1307 USA

 *

 */

#include <linux/module.h>

#include <linux/spinlock.h>

#include <linux/io.h>

#include <linux/of.h>

#include <linux/clkdev.h>

#include <linux/clk-provider.h>

#include <linux/of_address.h>

#include <asm/setup.h>



/* Register SCU_PCPPLL bit fields */

#define N_DIV_RD(src)			(((src) & 0x000001ff))



/* Register SCU_SOCPLL bit fields */

#define CLKR_RD(src)			(((src) & 0x07000000)>>24)

#define CLKOD_RD(src)			(((src) & 0x00300000)>>20)

#define REGSPEC_RESET_F1_MASK		0x00010000

#define CLKF_RD(src)			(((src) & 0x000001ff))



#define XGENE_CLK_DRIVER_VER		"0.1"



static DEFINE_SPINLOCK(clk_lock);



static inline u32 xgene_clk_read(void *csr)

{

	return readl_relaxed(csr);

}



static inline void xgene_clk_write(u32 data, void *csr)

{

	return writel_relaxed(data, csr);

}



/* PLL Clock */

enum xgene_pll_type {

	PLL_TYPE_PCP = 0,

	PLL_TYPE_SOC = 1,

};



struct xgene_clk_pll {

	struct clk_hw	hw;

	const char	*name;

	void __iomem	*reg;

	spinlock_t	*lock;

	u32		pll_offset;

	enum xgene_pll_type	type;

};



#define to_xgene_clk_pll(_hw) container_of(_hw, struct xgene_clk_pll, hw)



static int xgene_clk_pll_is_enabled(struct clk_hw *hw)

{

	struct xgene_clk_pll *pllclk = to_xgene_clk_pll(hw);

	u32 data;



	data = xgene_clk_read(pllclk->reg + pllclk->pll_offset);

	pr_debug("%s pll %s\n", pllclk->name,

		data & REGSPEC_RESET_F1_MASK ? "disabled" : "enabled");



	return data & REGSPEC_RESET_F1_MASK ? 0 : 1;

}



static unsigned long xgene_clk_pll_recalc_rate(struct clk_hw *hw,

				unsigned long parent_rate)

{

	struct xgene_clk_pll *pllclk = to_xgene_clk_pll(hw);

	unsigned long fref;

	unsigned long fvco;

	u32 pll;

	u32 nref;

	u32 nout;

	u32 nfb;



	pll = xgene_clk_read(pllclk->reg + pllclk->pll_offset);



	if (pllclk->type == PLL_TYPE_PCP) {

		/*

		 * PLL VCO = Reference clock * NF

		 * PCP PLL = PLL_VCO / 2

		 */

		nout = 2;

		fvco = parent_rate * (N_DIV_RD(pll) + 4);

	} else {

		/*

		 * Fref = Reference Clock / NREF;

		 * Fvco = Fref * NFB;

		 * Fout = Fvco / NOUT;

		 */

		nref = CLKR_RD(pll) + 1;

		nout = CLKOD_RD(pll) + 1;

		nfb = CLKF_RD(pll);

		fref = parent_rate / nref;

		fvco = fref * nfb;

	}

	pr_debug("%s pll recalc rate %ld parent %ld\n", pllclk->name,

		fvco / nout, parent_rate);



	return fvco / nout;

}



const struct clk_ops xgene_clk_pll_ops = {

	.is_enabled = xgene_clk_pll_is_enabled,

	.recalc_rate = xgene_clk_pll_recalc_rate,

};



static struct clk *xgene_register_clk_pll(struct device *dev,

	const char *name, const char *parent_name,

	unsigned long flags, void __iomem *reg, u32 pll_offset,

	u32 type, spinlock_t *lock)

{

	struct xgene_clk_pll *apmclk;

	struct clk *clk;

	struct clk_init_data init;



	/* allocate the APM clock structure */

	apmclk = kzalloc(sizeof(*apmclk), GFP_KERNEL);

	if (!apmclk) {

		pr_err("%s: could not allocate APM clk\n", __func__);

		return ERR_PTR(-ENOMEM);

	}



	init.name = name;

	init.ops = &xgene_clk_pll_ops;

	init.flags = flags;

	init.parent_names = parent_name ? &parent_name : NULL;

	init.num_parents = parent_name ? 1 : 0;



	apmclk->name = name;

	apmclk->reg = reg;

	apmclk->lock = lock;

	apmclk->pll_offset = pll_offset;

	apmclk->type = type;

	apmclk->hw.init = &init;



	/* Register the clock */

	clk = clk_register(dev, &apmclk->hw);

	if (IS_ERR(clk)) {

		pr_err("%s: could not register clk %s\n", __func__, name);

		kfree(apmclk);

		return NULL;

	}

	return clk;

}



static void xgene_pllclk_init(struct device_node *np, enum xgene_pll_type pll_type)

{

        const char *clk_name = np->full_name;

        struct clk *clk;

        void *reg;



        reg = of_iomap(np, 0);

        if (reg == NULL) {

                pr_err("Unable to map CSR register for %s\n", np->full_name);

                return;

        }

        of_property_read_string(np, "clock-output-names", &clk_name);

        clk = xgene_register_clk_pll(NULL,

                        clk_name, of_clk_get_parent_name(np, 0),

                        CLK_IS_ROOT, reg, 0, pll_type, &clk_lock);

        if (!IS_ERR(clk)) {

                of_clk_add_provider(np, of_clk_src_simple_get, clk);

                clk_register_clkdev(clk, clk_name, NULL);

                pr_debug("Add %s clock PLL\n", clk_name);

        }

}



static void xgene_socpllclk_init(struct device_node *np)

{

	xgene_pllclk_init(np, PLL_TYPE_SOC);

}



static void xgene_pcppllclk_init(struct device_node *np)

{

	xgene_pllclk_init(np, PLL_TYPE_PCP);

}



/* IP Clock */

struct xgene_dev_parameters {

	void __iomem *csr_reg;		/* CSR for IP clock */

	u32 reg_clk_offset;		/* Offset to clock enable CSR */

	u32 reg_clk_mask;		/* Mask bit for clock enable */

	u32 reg_csr_offset;		/* Offset to CSR reset */

	u32 reg_csr_mask;		/* Mask bit for disable CSR reset */

	void __iomem *divider_reg;	/* CSR for divider */

	u32 reg_divider_offset;		/* Offset to divider register */

	u32 reg_divider_shift;		/* Bit shift to divider field */

	u32 reg_divider_width;		/* Width of the bit to divider field */

};



struct xgene_clk {

	struct clk_hw	hw;

	const char	*name;

	spinlock_t	*lock;

	struct xgene_dev_parameters	param;

};



#define to_xgene_clk(_hw) container_of(_hw, struct xgene_clk, hw)



static int xgene_clk_enable(struct clk_hw *hw)

{

	struct xgene_clk *pclk = to_xgene_clk(hw);

	unsigned long flags = 0;

	u32 data;



	if (pclk->lock)

		spin_lock_irqsave(pclk->lock, flags);



	if (pclk->param.csr_reg != NULL) {

		pr_debug("%s clock enabled\n", pclk->name);

		/* First enable the clock */

		data = xgene_clk_read(pclk->param.csr_reg +

					pclk->param.reg_clk_offset);

		data |= pclk->param.reg_clk_mask;

		xgene_clk_write(data, pclk->param.csr_reg +

					pclk->param.reg_clk_offset);

		pr_debug("%s clock PADDR base 0x%016LX clk offset 0x%08X mask 0x%08X value 0x%08X\n",

			pclk->name, __pa(pclk->param.csr_reg),

			pclk->param.reg_clk_offset, pclk->param.reg_clk_mask,

			data);



		/* Second enable the CSR */

		data = xgene_clk_read(pclk->param.csr_reg +

					pclk->param.reg_csr_offset);

		data &= ~pclk->param.reg_csr_mask;

		xgene_clk_write(data, pclk->param.csr_reg +

					pclk->param.reg_csr_offset);

		pr_debug("%s CSR RESET PADDR base 0x%016LX csr offset 0x%08X mask 0x%08X value 0x%08X\n",

			pclk->name, __pa(pclk->param.csr_reg),

			pclk->param.reg_csr_offset, pclk->param.reg_csr_mask,

			data);

	}



	if (pclk->lock)

		spin_unlock_irqrestore(pclk->lock, flags);



	return 0;

}



static void xgene_clk_disable(struct clk_hw *hw)

{

	struct xgene_clk *pclk = to_xgene_clk(hw);

	unsigned long flags = 0;

	u32 data;



	if (pclk->lock)

		spin_lock_irqsave(pclk->lock, flags);



	if (pclk->param.csr_reg != NULL) {

		pr_debug("%s clock disabled\n", pclk->name);

		/* First put the CSR in reset */

		data = xgene_clk_read(pclk->param.csr_reg +

					pclk->param.reg_csr_offset);

		data |= pclk->param.reg_csr_mask;

		xgene_clk_write(data, pclk->param.csr_reg +

					pclk->param.reg_csr_offset);



		/* Second disable the clock */

		data = xgene_clk_read(pclk->param.csr_reg +

					pclk->param.reg_clk_offset);

		data &= ~pclk->param.reg_clk_mask;

		xgene_clk_write(data, pclk->param.csr_reg +

					pclk->param.reg_clk_offset);

	}



	if (pclk->lock)

		spin_unlock_irqrestore(pclk->lock, flags);

}



static int xgene_clk_is_enabled(struct clk_hw *hw)

{

	struct xgene_clk *pclk = to_xgene_clk(hw);

	u32 data = 0;



	if (pclk->param.csr_reg != NULL) {

		pr_debug("%s clock checking\n", pclk->name);

		data = xgene_clk_read(pclk->param.csr_reg +

					pclk->param.reg_clk_offset);

		pr_debug("%s clock is %s\n", pclk->name,

			data & pclk->param.reg_clk_mask ? "enabled" :

							"disabled");

	}



	if (pclk->param.csr_reg == NULL)

		return 1;

	return data & pclk->param.reg_clk_mask ? 1 : 0;

}



static unsigned long xgene_clk_recalc_rate(struct clk_hw *hw,

				unsigned long parent_rate)

{

	struct xgene_clk *pclk = to_xgene_clk(hw);

	u32 data;



	if (pclk->param.divider_reg) {

		data = xgene_clk_read(pclk->param.divider_reg +

					pclk->param.reg_divider_offset);

		data >>= pclk->param.reg_divider_shift;

		data &= (1 << pclk->param.reg_divider_width) - 1;



		pr_debug("%s clock recalc rate %ld parent %ld\n",

			pclk->name, parent_rate / data, parent_rate);

		return parent_rate / data;

	} else {

		pr_debug("%s clock recalc rate %ld parent %ld\n",

			pclk->name, parent_rate, parent_rate);

		return parent_rate;

	}

}



static int xgene_clk_set_rate(struct clk_hw *hw, unsigned long rate,

				unsigned long parent_rate)

{

	struct xgene_clk *pclk = to_xgene_clk(hw);

	unsigned long flags = 0;

	u32 data;

	u32 divider;

	u32 divider_save;



	if (pclk->lock)

		spin_lock_irqsave(pclk->lock, flags);



	if (pclk->param.divider_reg) {

		/* Let's compute the divider */

		if (rate > parent_rate)

			rate = parent_rate;

		divider_save = divider = parent_rate / rate; /* Rounded down */

		divider &= (1 << pclk->param.reg_divider_width) - 1;

		divider <<= pclk->param.reg_divider_shift;



		/* Set new divider */

		data = xgene_clk_read(pclk->param.divider_reg +

				pclk->param.reg_divider_offset);

		data &= ~((1 << pclk->param.reg_divider_width) - 1);

		data |= divider;

		xgene_clk_write(data, pclk->param.divider_reg +

					pclk->param.reg_divider_offset);

		pr_debug("%s clock set rate %ld\n", pclk->name,

			parent_rate / divider_save);

	} else {

		divider_save = 1;

	}



	if (pclk->lock)

		spin_unlock_irqrestore(pclk->lock, flags);



	return parent_rate / divider_save;

}



static long xgene_clk_round_rate(struct clk_hw *hw, unsigned long rate,

				unsigned long *prate)

{

	struct xgene_clk *pclk = to_xgene_clk(hw);

	unsigned long parent_rate = *prate;

	u32 divider;



	if (pclk->param.divider_reg) {

		/* Let's compute the divider */

		if (rate > parent_rate)

			rate = parent_rate;

		divider = parent_rate / rate;   /* Rounded down */

	} else {

		divider = 1;

	}



	return parent_rate / divider;

}



const struct clk_ops xgene_clk_ops = {

	.enable = xgene_clk_enable,

	.disable = xgene_clk_disable,

	.is_enabled = xgene_clk_is_enabled,

	.recalc_rate = xgene_clk_recalc_rate,

	.set_rate = xgene_clk_set_rate,

	.round_rate = xgene_clk_round_rate,

};



static struct clk *xgene_register_clk(struct device *dev,

		const char *name, const char *parent_name,

		struct xgene_dev_parameters *parameters, spinlock_t *lock)

{

	struct xgene_clk *apmclk;

	struct clk *clk;

	struct clk_init_data init;

	int rc;



	/* allocate the APM clock structure */

	apmclk = kzalloc(sizeof(*apmclk), GFP_KERNEL);

	if (!apmclk) {

		pr_err("%s: could not allocate APM clk\n", __func__);

		return ERR_PTR(-ENOMEM);

	}



	init.name = name;

	init.ops = &xgene_clk_ops;

	init.flags = 0;

	init.parent_names = parent_name ? &parent_name : NULL;

	init.num_parents = parent_name ? 1 : 0;



	apmclk->name = name;

	apmclk->lock = lock;

	apmclk->hw.init = &init;

	apmclk->param = *parameters;



	/* Register the clock */

	clk = clk_register(dev, &apmclk->hw);

	if (IS_ERR(clk)) {

		pr_err("%s: could not register clk %s\n", __func__, name);

		kfree(apmclk);

		return clk;

	}



	/* Register the clock for lookup */

	rc = clk_register_clkdev(clk, name, NULL);

	if (rc != 0) {

		pr_err("%s: could not register lookup clk %s\n",

			__func__, name);

	}

	return clk;

}



static void __init xgene_devclk_init(struct device_node *np)

{

	const char *clk_name = np->full_name;

	struct clk *clk;

	struct resource res;

	int rc;

	struct xgene_dev_parameters parameters;

	int i;



	/* Check if the entry is disabled */

        if (!of_device_is_available(np))

                return;



	/* Parse the DTS register for resource */

	parameters.csr_reg = NULL;

	parameters.divider_reg = NULL;

	for (i = 0; i < 2; i++) {

		void *map_res;

		rc = of_address_to_resource(np, i, &res);

		if (rc != 0) {

			if (i == 0) {

				pr_err("no DTS register for %s\n", 

					np->full_name);

				return;

			}

			break;

		}

		map_res = of_iomap(np, i);

		if (map_res == NULL) {

			pr_err("Unable to map resource %d for %s\n",

				i, np->full_name);

			goto err;

		}

		if (strcmp(res.name, "div-reg") == 0)

			parameters.divider_reg = map_res;

		else /* if (strcmp(res->name, "csr-reg") == 0) */

			parameters.csr_reg = map_res;

	}

	if (of_property_read_u32(np, "csr-offset", &parameters.reg_csr_offset))

		parameters.reg_csr_offset = 0;

	if (of_property_read_u32(np, "csr-mask", &parameters.reg_csr_mask))

		parameters.reg_csr_mask = 0xF;

	if (of_property_read_u32(np, "enable-offset",

				&parameters.reg_clk_offset))

		parameters.reg_clk_offset = 0x8;

	if (of_property_read_u32(np, "enable-mask", &parameters.reg_clk_mask))

		parameters.reg_clk_mask = 0xF;

	if (of_property_read_u32(np, "divider-offset",

				&parameters.reg_divider_offset))

		parameters.reg_divider_offset = 0;

	if (of_property_read_u32(np, "divider-width",

				&parameters.reg_divider_width))

		parameters.reg_divider_width = 0;

	if (of_property_read_u32(np, "divider-shift",

				&parameters.reg_divider_shift))

		parameters.reg_divider_shift = 0;

	of_property_read_string(np, "clock-output-names", &clk_name);



	clk = xgene_register_clk(NULL, clk_name,

		of_clk_get_parent_name(np, 0), &parameters, &clk_lock);

	if (IS_ERR(clk))

		goto err;

	pr_debug("Add %s clock\n", clk_name);

	rc = of_clk_add_provider(np, of_clk_src_simple_get, clk);

	if (rc != 0)

		pr_err("%s: could register provider clk %s\n", __func__,

			np->full_name);



	return;



err:

	if (parameters.csr_reg)

		iounmap(parameters.csr_reg);

	if (parameters.divider_reg)

		iounmap(parameters.divider_reg);

}



CLK_OF_DECLARE(xgene_socpll_clock, "apm,xgene-socpll-clock", xgene_socpllclk_init);

CLK_OF_DECLARE(xgene_pcppll_clock, "apm,xgene-pcppll-clock", xgene_pcppllclk_init);

CLK_OF_DECLARE(xgene_dev_clock, "apm,xgene-device-clock", xgene_devclk_init);