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[1/3] clk: Add APM X-Gene SoC clock driver for reference, PLL, and device clocks.

Message ID 1371828605-18053-2-git-send-email-lho@apm.com (mailing list archive)
State New, archived
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Commit Message

Loc Ho June 21, 2013, 3:30 p.m. UTC 
clk: Add APM X-Gene SoC clock driver for reference, PLL, and device clocks.

Signed-off-by: Loc Ho <lho@apm.com>
Signed-off-by: Kumar Sankaran <ksankaran@apm.com>
Signed-off-by: Vinayak Kale <vkale@apm.com>
Signed-off-by: Feng Kan <fkan@apm.com>
---
 drivers/clk/Kconfig     |    7 +
 drivers/clk/Makefile    |    1 +
 drivers/clk/clk-xgene.c |  538 +++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 546 insertions(+), 0 deletions(-)
 create mode 100644 drivers/clk/clk-xgene.c

Comments

Catalin Marinas June 21, 2013, 4:43 p.m. UTC | #1 
On Fri, Jun 21, 2013 at 04:30:03PM +0100, Loc Ho wrote:
> clk: Add APM X-Gene SoC clock driver for reference, PLL, and device clocks.
> 
> Signed-off-by: Loc Ho <lho@apm.com>
> Signed-off-by: Kumar Sankaran <ksankaran@apm.com>
> Signed-off-by: Vinayak Kale <vkale@apm.com>
> Signed-off-by: Feng Kan <fkan@apm.com>
> ---
>  drivers/clk/Kconfig     |    7 +
>  drivers/clk/Makefile    |    1 +
>  drivers/clk/clk-xgene.c |  538 +++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 546 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/clk/clk-xgene.c
> 
> diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
> index 0357ac4..aa4d8b6 100644
> --- a/drivers/clk/Kconfig
> +++ b/drivers/clk/Kconfig
> @@ -81,6 +81,13 @@ config COMMON_CLK_AXI_CLKGEN
>           Support for the Analog Devices axi-clkgen pcore clock generator for Xilinx
>           FPGAs. It is commonly used in Analog Devices' reference designs.
> 
> +config COMMON_CLK_XGENE
> +       bool "Clock driver for APM XGene SoC"
> +       default y
> +       depends on ARCH_XGENE
> +       ---help---
> +         Sypport for the APM X-Gene SoC reference, PLL, and device clocks.

Like the recent vexpress changes, you can make this depend on ARM64
only.
Mark Rutland June 24, 2013, 8:48 a.m. UTC | #2 
Hi,

I have some general comments, mostly on the devicetree side of things.

On Fri, Jun 21, 2013 at 04:30:03PM +0100, Loc Ho wrote:
> clk: Add APM X-Gene SoC clock driver for reference, PLL, and device clocks.
> 
> Signed-off-by: Loc Ho <lho@apm.com>
> Signed-off-by: Kumar Sankaran <ksankaran@apm.com>
> Signed-off-by: Vinayak Kale <vkale@apm.com>
> Signed-off-by: Feng Kan <fkan@apm.com>
> ---
>  drivers/clk/Kconfig     |    7 +
>  drivers/clk/Makefile    |    1 +
>  drivers/clk/clk-xgene.c |  538 +++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 546 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/clk/clk-xgene.c
> 
> diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
> index 0357ac4..aa4d8b6 100644
> --- a/drivers/clk/Kconfig
> +++ b/drivers/clk/Kconfig
> @@ -81,6 +81,13 @@ config COMMON_CLK_AXI_CLKGEN
>           Support for the Analog Devices axi-clkgen pcore clock generator for Xilinx
>           FPGAs. It is commonly used in Analog Devices' reference designs.
> 
> +config COMMON_CLK_XGENE
> +       bool "Clock driver for APM XGene SoC"
> +       default y
> +       depends on ARCH_XGENE
> +       ---help---
> +         Sypport for the APM X-Gene SoC reference, PLL, and device clocks.
> +
>  endmenu
> 
>  source "drivers/clk/mvebu/Kconfig"
> diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
> index 137d3e7..4c96337 100644
> --- a/drivers/clk/Makefile
> +++ b/drivers/clk/Makefile
> @@ -39,3 +39,4 @@ obj-$(CONFIG_COMMON_CLK_WM831X) += clk-wm831x.o
>  obj-$(CONFIG_COMMON_CLK_MAX77686) += clk-max77686.o
>  obj-$(CONFIG_COMMON_CLK_SI5351) += clk-si5351.o
>  obj-$(CONFIG_CLK_TWL6040)      += clk-twl6040.o
> +obj-$(CONFIG_COMMON_CLK_XGENE)  += clk-xgene.o
> diff --git a/drivers/clk/clk-xgene.c b/drivers/clk/clk-xgene.c
> new file mode 100644
> index 0000000..8b81e89
> --- /dev/null
> +++ b/drivers/clk/clk-xgene.c
> @@ -0,0 +1,538 @@
> +/*
> + * 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(struct xgene_clk_pll), GFP_KERNEL);

You can do apmclk = kzalloc(sizeof(*apmclk), GFP_KERNEL) here, which is more
robust with respect to type changes in future revisions of the driver.

> +       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)
> +{
> +       struct resource res;
> +       const char *clk_name = np->full_name;
> +       struct clk *clk;
> +       void *reg;
> +       int rc;
> +       u32 type;
> +
> +       rc = of_address_to_resource(np, 0, &res);
> +       if (rc != 0) {
> +               pr_err("no DTS CSR register for %s\n", np->full_name);
> +               return;
> +       }
> +       reg = ioremap(res.start, resource_size(&res));

You could just use reg = of_iomap(np, 0) here.

> +       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);
> +       if (of_property_read_u32(np, "type", &type))
> +               type = 0;
> +
> +       clk = xgene_register_clk_pll(NULL,
> +                       clk_name, of_clk_get_parent_name(np, 0),
> +                       CLK_IS_ROOT, reg, 0, 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);
> +       }
> +}
> +
> +/* IP Clock */
> +struct xgene_dev_parameters {
> +       u32  flags;                     /* Any flags to the clock framework */
> +       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(struct xgene_clk), GFP_KERNEL);

Again, you could use 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 = parameters->flags;
> +       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 NULL;

As I understand it, NULL is a valid clock. Should you not return clk (which is
an error value) here?

> +       }
> +
> +       /* 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;
> +
> +       rc = of_address_to_resource(np, 0, &res);
> +       if (rc != 0) {
> +               pr_err("no DTS CSR register for %s\n", np->full_name);
> +               return;
> +       }
> +       if (resource_size(&res)) {
> +               parameters.csr_reg = ioremap(res.start, resource_size(&res));
> +               if (parameters.csr_reg == NULL) {
> +                       pr_err("Unable to map CSR register for %s\n",
> +                               np->full_name);
> +                       return;
> +               }

Use of_iomap(np, 0) here.

> +       } else {
> +               parameters.csr_reg = NULL;
> +       }

Are you able to continue if this is the case?

> +
> +       rc = of_address_to_resource(np, 1, &res);
> +       if (rc != 0) {
> +               pr_err("no DTS DIV register for %s\n", np->full_name);
> +               return;
> +       }
> +       if (resource_size(&res)) {
> +               parameters.divider_reg = ioremap(res.start,
> +                                               resource_size(&res));
> +               if (parameters.divider_reg == NULL) {
> +                       pr_err("Unable to map DIV register for %s\n",
> +                               np->full_name);
> +                       if (parameters.csr_reg)
> +                               iounmap(parameters.csr_reg);
> +                       return;
> +               }

Use of_iomap(np, 1) here.

> +       } else {
> +               parameters.divider_reg = NULL;
> +       }

Similarly, are you able to continue with this being the case?

> +       if (of_property_read_u32(np, "flags", &parameters.flags))
> +               parameters.flags = 0;
> +       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)) {
> +               if (parameters.csr_reg)
> +                       iounmap(parameters.csr_reg);
> +               if (parameters.divider_reg)
> +                       iounmap(parameters.divider_reg);
> +               return;
> +       }
> +       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;
> +       }
> +}
> +
> +CLK_OF_DECLARE(fixed_clock, "fixed-clock", of_fixed_clk_setup);
> +CLK_OF_DECLARE(fixed_factor_clock, "fixed-factor-clock",
> +               of_fixed_factor_clk_setup);

Why are these declared in your driver? Both fixed-clock and fixed-factor-clock
are standard clock bindings with existing drivers which already have
CLK_OF_DECLARE. Having a duplicate CLK_OF_DECLARE for those compatible strings
is only going to cause problems.

See drivers/clk/clk-fixed-rate.c and drivers/clk/clk-fixed-factor.c.

> +CLK_OF_DECLARE(xgene_pll_clock, "apm,xgene-pll-clock", xgene_pllclk_init);
> +CLK_OF_DECLARE(xgene_dev_clock, "apm,xgene-device-clock", xgene_devclk_init);
> +
> +static int __init xgene_clk_init(void)
> +{
> +       pr_info("XGene clock driver v%s\n", XGENE_CLK_DRIVER_VER);
> +       of_clk_init(NULL);

As of_clk_init is called in arm64_device_init, why do you call it here? It
looks very odd and I suspect you don't need it.

> +       return 0;
> +}
> +arch_initcall(xgene_clk_init);

I think this initcall can go.

Thanks,
Mark
Loc Ho June 24, 2013, 5:48 p.m. UTC | #3 
Hi,

I will fix them. With regard to continue where the CSR is NULL, it is
possible to continue as long as both is NOT NULL.

> Use of_iomap(np, 0) here.
>
>> +       } else {
>> +               parameters.csr_reg = NULL;
>> +       }
>
> Are you able to continue if this is the case?
>
>> +
>> +       rc = of_address_to_resource(np, 1, &res);
>> +       if (rc != 0) {
>> +               pr_err("no DTS DIV register for %s\n", np->full_name);
>> +               return;
>> +       }
>> +       if (resource_size(&res)) {
>> +               parameters.divider_reg = ioremap(res.start,
>> +                                               resource_size(&res));
>> +               if (parameters.divider_reg == NULL) {
>> +                       pr_err("Unable to map DIV register for %s\n",
>> +                               np->full_name);
>> +                       if (parameters.csr_reg)
>> +                               iounmap(parameters.csr_reg);
>> +                       return;
>> +               }
>
> Use of_iomap(np, 1) here.
>
>> +       } else {
>> +               parameters.divider_reg = NULL;
>> +       }
>
> Similarly, are you able to continue with this being the case?

-Loc
Mark Rutland June 24, 2013, 7:24 p.m. UTC | #4 
On Mon, Jun 24, 2013 at 06:48:56PM +0100, Loc Ho wrote:
> Hi,
> 
> I will fix them. With regard to continue where the CSR is NULL, it is
> possible to continue as long as both is NOT NULL.

Ah, so one bank of registers might not be present? Given that, it might
be worth using interrupt-names to describe which is present, so that you
don't need to describe a non-existent register bank.

Thanks,
Mark.

> 
> > Use of_iomap(np, 0) here.
> >
> >> +       } else {
> >> +               parameters.csr_reg = NULL;
> >> +       }
> >
> > Are you able to continue if this is the case?
> >
> >> +
> >> +       rc = of_address_to_resource(np, 1, &res);
> >> +       if (rc != 0) {
> >> +               pr_err("no DTS DIV register for %s\n", np->full_name);
> >> +               return;
> >> +       }
> >> +       if (resource_size(&res)) {
> >> +               parameters.divider_reg = ioremap(res.start,
> >> +                                               resource_size(&res));
> >> +               if (parameters.divider_reg == NULL) {
> >> +                       pr_err("Unable to map DIV register for %s\n",
> >> +                               np->full_name);
> >> +                       if (parameters.csr_reg)
> >> +                               iounmap(parameters.csr_reg);
> >> +                       return;
> >> +               }
> >
> > Use of_iomap(np, 1) here.
> >
> >> +       } else {
> >> +               parameters.divider_reg = NULL;
> >> +       }
> >
> > Similarly, are you able to continue with this being the case?
> 
> -Loc
>
diff mbox

Patch

diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
index 0357ac4..aa4d8b6 100644
--- a/drivers/clk/Kconfig
+++ b/drivers/clk/Kconfig
@@ -81,6 +81,13 @@  config COMMON_CLK_AXI_CLKGEN
 	  Support for the Analog Devices axi-clkgen pcore clock generator for Xilinx
 	  FPGAs. It is commonly used in Analog Devices' reference designs.
 
+config COMMON_CLK_XGENE
+	bool "Clock driver for APM XGene SoC"
+	default y
+	depends on ARCH_XGENE
+	---help---
+	  Sypport for the APM X-Gene SoC reference, PLL, and device clocks.
+
 endmenu
 
 source "drivers/clk/mvebu/Kconfig"
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index 137d3e7..4c96337 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -39,3 +39,4 @@  obj-$(CONFIG_COMMON_CLK_WM831X) += clk-wm831x.o
 obj-$(CONFIG_COMMON_CLK_MAX77686) += clk-max77686.o
 obj-$(CONFIG_COMMON_CLK_SI5351) += clk-si5351.o
 obj-$(CONFIG_CLK_TWL6040)	+= clk-twl6040.o
+obj-$(CONFIG_COMMON_CLK_XGENE)  += clk-xgene.o
diff --git a/drivers/clk/clk-xgene.c b/drivers/clk/clk-xgene.c
new file mode 100644
index 0000000..8b81e89
--- /dev/null
+++ b/drivers/clk/clk-xgene.c
@@ -0,0 +1,538 @@ 
+/*
+ * 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(struct xgene_clk_pll), 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)
+{
+	struct resource res;
+	const char *clk_name = np->full_name;
+	struct clk *clk;
+	void *reg;
+	int rc;
+	u32 type;
+
+	rc = of_address_to_resource(np, 0, &res);
+	if (rc != 0) {
+		pr_err("no DTS CSR register for %s\n", np->full_name);
+		return;
+	}
+	reg = ioremap(res.start, resource_size(&res));
+	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);
+	if (of_property_read_u32(np, "type", &type))
+		type = 0;
+
+	clk = xgene_register_clk_pll(NULL,
+			clk_name, of_clk_get_parent_name(np, 0),
+			CLK_IS_ROOT, reg, 0, 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);
+	}
+}
+
+/* IP Clock */
+struct xgene_dev_parameters {
+	u32  flags;			/* Any flags to the clock framework */
+	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(struct xgene_clk), 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 = parameters->flags;
+	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 NULL;
+	}
+
+	/* 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;
+
+	rc = of_address_to_resource(np, 0, &res);
+	if (rc != 0) {
+		pr_err("no DTS CSR register for %s\n", np->full_name);
+		return;
+	}
+	if (resource_size(&res)) {
+		parameters.csr_reg = ioremap(res.start, resource_size(&res));
+		if (parameters.csr_reg == NULL) {
+			pr_err("Unable to map CSR register for %s\n",
+				np->full_name);
+			return;
+		}
+	} else {
+		parameters.csr_reg = NULL;
+	}
+
+	rc = of_address_to_resource(np, 1, &res);
+	if (rc != 0) {
+		pr_err("no DTS DIV register for %s\n", np->full_name);
+		return;
+	}
+	if (resource_size(&res)) {
+		parameters.divider_reg = ioremap(res.start,
+						resource_size(&res));
+		if (parameters.divider_reg == NULL) {
+			pr_err("Unable to map DIV register for %s\n",
+				np->full_name);
+			if (parameters.csr_reg)
+				iounmap(parameters.csr_reg);
+			return;
+		}
+	} else {
+		parameters.divider_reg = NULL;
+	}
+	if (of_property_read_u32(np, "flags", &parameters.flags))
+		parameters.flags = 0;
+	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)) {
+		if (parameters.csr_reg)
+			iounmap(parameters.csr_reg);
+		if (parameters.divider_reg)
+			iounmap(parameters.divider_reg);
+		return;
+	}
+	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;
+	}
+}
+
+CLK_OF_DECLARE(fixed_clock, "fixed-clock", of_fixed_clk_setup);
+CLK_OF_DECLARE(fixed_factor_clock, "fixed-factor-clock",
+		of_fixed_factor_clk_setup);
+CLK_OF_DECLARE(xgene_pll_clock, "apm,xgene-pll-clock", xgene_pllclk_init);
+CLK_OF_DECLARE(xgene_dev_clock, "apm,xgene-device-clock", xgene_devclk_init);
+
+static int __init xgene_clk_init(void)
+{
+	pr_info("XGene clock driver v%s\n", XGENE_CLK_DRIVER_VER);
+	of_clk_init(NULL);
+	return 0;
+}
+arch_initcall(xgene_clk_init);