Subject: Re: [PATCH V4 3/5] clk: imx: Support building i.MX common clock
driver as module

On Thu, Jul 2, 2020 at 10:19 AM Anson Huang [off-list ref]
wrote:

quoted

There are more and more requirements of building SoC specific drivers
as modules, add support for building i.MX common clock driver as
module to meet the requirement.

Signed-off-by: Anson Huang <redacted>
---
Changes since V3:
        - ONLY include __setup_param() build for built-in, module build no

need

quoted

          to have it.
---
 drivers/clk/imx/Kconfig            |  8 ++++++--
 drivers/clk/imx/Makefile           | 40

+++++++++++++++++++-------------------

quoted

 drivers/clk/imx/clk-composite-8m.c |  2 ++
 drivers/clk/imx/clk-cpu.c          |  2 ++
 drivers/clk/imx/clk-frac-pll.c     |  2 ++
 drivers/clk/imx/clk-gate2.c        |  2 ++
 drivers/clk/imx/clk-pll14xx.c      |  5 +++++
 drivers/clk/imx/clk-sscg-pll.c     |  2 ++
 drivers/clk/imx/clk.c              | 22 +++++++++++++++------
 9 files changed, 57 insertions(+), 28 deletions(-)

diff --git a/drivers/clk/imx/Kconfig b/drivers/clk/imx/Kconfig index

09fc8ad..f6ddf76 100644

--- a/drivers/clk/imx/Kconfig
+++ b/drivers/clk/imx/Kconfig

@@ -1,8 +1,8 @@
 # SPDX-License-Identifier: GPL-2.0
 # common clock support for NXP i.MX SoC family.
 config MXC_CLK
-       bool
-       def_bool ARCH_MXC
+       tristate "IMX clock"
+       depends on ARCH_MXC

 config MXC_CLK_SCU
        bool

@@ -101,24 +101,28 @@ config CLK_VF610  config CLK_IMX8MM
        bool "IMX8MM CCM Clock Driver"
        depends on ARCH_MXC
+       select MXC_CLK
        help
            Build the driver for i.MX8MM CCM Clock Driver

 config CLK_IMX8MN
        bool "IMX8MN CCM Clock Driver"
        depends on ARCH_MXC
+       select MXC_CLK
        help
            Build the driver for i.MX8MN CCM Clock Driver

 config CLK_IMX8MP
        bool "IMX8MP CCM Clock Driver"
        depends on ARCH_MXC
+       select MXC_CLK
        help
            Build the driver for i.MX8MP CCM Clock Driver

 config CLK_IMX8MQ
        bool "IMX8MQ CCM Clock Driver"
        depends on ARCH_MXC
+       select MXC_CLK
        help
            Build the driver for i.MX8MQ CCM Clock Driver

diff --git a/drivers/clk/imx/Makefile b/drivers/clk/imx/Makefile index

394ade7..17f5d12 100644

--- a/drivers/clk/imx/Makefile
+++ b/drivers/clk/imx/Makefile

@@ -1,25 +1,25 @@
 # SPDX-License-Identifier: GPL-2.0

-obj-$(CONFIG_MXC_CLK) += \
-       clk.o \
-       clk-busy.o \
-       clk-composite-8m.o \
-       clk-cpu.o \
-       clk-composite-7ulp.o \
-       clk-divider-gate.o \
-       clk-fixup-div.o \
-       clk-fixup-mux.o \
-       clk-frac-pll.o \
-       clk-gate-exclusive.o \
-       clk-gate2.o \
-       clk-pfd.o \
-       clk-pfdv2.o \
-       clk-pllv1.o \
-       clk-pllv2.o \
-       clk-pllv3.o \
-       clk-pllv4.o \
-       clk-sscg-pll.o \
-       clk-pll14xx.o
+mxc-clk-objs += clk.o
+mxc-clk-objs += clk-busy.o
+mxc-clk-objs += clk-composite-7ulp.o
+mxc-clk-objs += clk-composite-8m.o
+mxc-clk-objs += clk-cpu.o
+mxc-clk-objs += clk-divider-gate.o
+mxc-clk-objs += clk-fixup-div.o
+mxc-clk-objs += clk-fixup-mux.o
+mxc-clk-objs += clk-frac-pll.o
+mxc-clk-objs += clk-gate2.o
+mxc-clk-objs += clk-gate-exclusive.o
+mxc-clk-objs += clk-pfd.o
+mxc-clk-objs += clk-pfdv2.o
+mxc-clk-objs += clk-pllv1.o
+mxc-clk-objs += clk-pllv2.o
+mxc-clk-objs += clk-pllv3.o
+mxc-clk-objs += clk-pllv4.o
+mxc-clk-objs += clk-pll14xx.o
+mxc-clk-objs += clk-sscg-pll.o
+obj-$(CONFIG_MXC_CLK) += mxc-clk.o

 obj-$(CONFIG_MXC_CLK_SCU) += \
        clk-scu.o \

diff --git a/drivers/clk/imx/clk-composite-8m.c

b/drivers/clk/imx/clk-composite-8m.c
index d2b5af8..78fb7e5 100644

--- a/drivers/clk/imx/clk-composite-8m.c
+++ b/drivers/clk/imx/clk-composite-8m.c

@@ -5,6 +5,7 @@

 #include <linux/clk-provider.h>
 #include <linux/errno.h>
+#include <linux/export.h>
 #include <linux/io.h>
 #include <linux/slab.h>

@@ -243,3 +244,4 @@ struct clk_hw

*imx8m_clk_hw_composite_flags(const char *name,

quoted

        kfree(mux);
        return ERR_CAST(hw);
 }
+EXPORT_SYMBOL_GPL(imx8m_clk_hw_composite_flags);

diff --git a/drivers/clk/imx/clk-cpu.c b/drivers/clk/imx/clk-cpu.c
index cb182be..cb6ca4c 100644
--- a/drivers/clk/imx/clk-cpu.c
+++ b/drivers/clk/imx/clk-cpu.c

@@ -5,6 +5,7 @@

 #include <linux/clk.h>
 #include <linux/clk-provider.h>
+#include <linux/export.h>
 #include <linux/slab.h>
 #include "clk.h"

@@ -104,3 +105,4 @@ struct clk_hw *imx_clk_hw_cpu(const char *name,

const char *parent_name,

        return hw;
 }
+EXPORT_SYMBOL_GPL(imx_clk_hw_cpu);

diff --git a/drivers/clk/imx/clk-frac-pll.c

b/drivers/clk/imx/clk-frac-pll.c index 101e0a3..c703056 100644

--- a/drivers/clk/imx/clk-frac-pll.c
+++ b/drivers/clk/imx/clk-frac-pll.c

@@ -10,6 +10,7 @@

 #include <linux/clk-provider.h>
 #include <linux/err.h>
+#include <linux/export.h>
 #include <linux/io.h>
 #include <linux/iopoll.h>
 #include <linux/slab.h>

@@ -233,3 +234,4 @@ struct clk_hw *imx_clk_hw_frac_pll(const char

*name,

        return hw;
 }
+EXPORT_SYMBOL_GPL(imx_clk_hw_frac_pll);

diff --git a/drivers/clk/imx/clk-gate2.c b/drivers/clk/imx/clk-gate2.c
index b87ab3c..512f675 100644
--- a/drivers/clk/imx/clk-gate2.c
+++ b/drivers/clk/imx/clk-gate2.c

@@ -7,6 +7,7 @@
  */

 #include <linux/clk-provider.h>
+#include <linux/export.h>
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/io.h>

@@ -177,3 +178,4 @@ struct clk_hw *clk_hw_register_gate2(struct device

*dev, const char *name,

        return hw;
 }
+EXPORT_SYMBOL_GPL(clk_hw_register_gate2);

diff --git a/drivers/clk/imx/clk-pll14xx.c

b/drivers/clk/imx/clk-pll14xx.c index f9eb189..f5c3e7e 100644

--- a/drivers/clk/imx/clk-pll14xx.c
+++ b/drivers/clk/imx/clk-pll14xx.c

@@ -6,6 +6,7 @@
 #include <linux/bitops.h>
 #include <linux/clk-provider.h>
 #include <linux/err.h>
+#include <linux/export.h>
 #include <linux/io.h>
 #include <linux/iopoll.h>
 #include <linux/slab.h>

@@ -68,6 +69,7 @@ struct imx_pll14xx_clk imx_1443x_pll = {
        .rate_table = imx_pll1443x_tbl,
        .rate_count = ARRAY_SIZE(imx_pll1443x_tbl),  };
+EXPORT_SYMBOL_GPL(imx_1443x_pll);

 struct imx_pll14xx_clk imx_1443x_dram_pll = {
        .type = PLL_1443X,

@@ -75,12 +77,14 @@ struct imx_pll14xx_clk imx_1443x_dram_pll = {
        .rate_count = ARRAY_SIZE(imx_pll1443x_tbl),
        .flags = CLK_GET_RATE_NOCACHE,
 };
+EXPORT_SYMBOL_GPL(imx_1443x_dram_pll);

 struct imx_pll14xx_clk imx_1416x_pll = {
        .type = PLL_1416X,
        .rate_table = imx_pll1416x_tbl,
        .rate_count = ARRAY_SIZE(imx_pll1416x_tbl),
 };
+EXPORT_SYMBOL_GPL(imx_1416x_pll);

 static const struct imx_pll14xx_rate_table *imx_get_pll_settings(
                struct clk_pll14xx *pll, unsigned long rate)

@@ -436,3 +440,4 @@ struct clk_hw *imx_dev_clk_hw_pll14xx(struct

device *dev, const char *name,

quoted

        return hw;
 }
+EXPORT_SYMBOL_GPL(imx_dev_clk_hw_pll14xx);

diff --git a/drivers/clk/imx/clk-sscg-pll.c b/drivers/clk/imx/clk-sscg-pll.c
index 773d8a5..9d6cdff 100644
--- a/drivers/clk/imx/clk-sscg-pll.c
+++ b/drivers/clk/imx/clk-sscg-pll.c

@@ -10,6 +10,7 @@

 #include <linux/clk-provider.h>
 #include <linux/err.h>
+#include <linux/export.h>
 #include <linux/io.h>
 #include <linux/iopoll.h>
 #include <linux/slab.h>

@@ -537,3 +538,4 @@ struct clk_hw *imx_clk_hw_sscg_pll(const char

*name,

quoted

        return hw;
 }
+EXPORT_SYMBOL_GPL(imx_clk_hw_sscg_pll);

diff --git a/drivers/clk/imx/clk.c b/drivers/clk/imx/clk.c
index 87ab8db..6f2a94d 100644
--- a/drivers/clk/imx/clk.c
+++ b/drivers/clk/imx/clk.c

@@ -3,6 +3,7 @@
 #include <linux/clk-provider.h>
 #include <linux/err.h>
 #include <linux/io.h>
+#include <linux/module.h>
 #include <linux/of.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>

@@ -13,6 +14,7 @@
 #define CCDR_MMDC_CH1_MASK             BIT(16)

 DEFINE_SPINLOCK(imx_ccm_lock);
+EXPORT_SYMBOL_GPL(imx_ccm_lock);

 void imx_unregister_clocks(struct clk *clks[], unsigned int count)
 {

@@ -29,8 +31,9 @@ void imx_unregister_hw_clocks(struct clk_hw *hws[],

unsigned int count)

quoted

        for (i = 0; i < count; i++)
                clk_hw_unregister(hws[i]);
 }
+EXPORT_SYMBOL_GPL(imx_unregister_hw_clocks);

-void __init imx_mmdc_mask_handshake(void __iomem *ccm_base,
+void imx_mmdc_mask_handshake(void __iomem *ccm_base,
                                    unsigned int chn)
 {
        unsigned int reg;

@@ -59,8 +62,9 @@ void imx_check_clk_hws(struct clk_hw *clks[],

unsigned int count)

quoted

                        pr_err("i.MX clk %u: register failed with %ld\n",
                               i, PTR_ERR(clks[i]));
 }
+EXPORT_SYMBOL_GPL(imx_check_clk_hws);

-static struct clk * __init imx_obtain_fixed_clock_from_dt(const char *name)
+static struct clk *imx_obtain_fixed_clock_from_dt(const char *name)
 {
        struct of_phandle_args phandle;
        struct clk *clk = ERR_PTR(-ENODEV);

@@ -80,7 +84,7 @@ static struct clk * __init

imx_obtain_fixed_clock_from_dt(const char *name)

quoted

        return clk;
 }

-struct clk * __init imx_obtain_fixed_clock(
+struct clk *imx_obtain_fixed_clock(
                        const char *name, unsigned long rate)
 {
        struct clk *clk;

@@ -91,7 +95,7 @@ struct clk * __init imx_obtain_fixed_clock(
        return clk;
 }

-struct clk_hw * __init imx_obtain_fixed_clock_hw(
+struct clk_hw *imx_obtain_fixed_clock_hw(
                        const char *name, unsigned long rate)
 {
        struct clk *clk;

@@ -113,6 +117,7 @@ struct clk_hw * imx_obtain_fixed_clk_hw(struct

device_node *np,

quoted

        return __clk_get_hw(clk);
 }
+EXPORT_SYMBOL_GPL(imx_obtain_fixed_clk_hw);

 /*
  * This fixups the register CCM_CSCMR1 write value.

@@ -143,16 +148,18 @@ void imx_cscmr1_fixup(u32 *val)
 static int imx_keep_uart_clocks;
 static struct clk ** const *imx_uart_clocks;

-static int __init imx_keep_uart_clocks_param(char *str)
+static int __maybe_unused imx_keep_uart_clocks_param(char *str)
 {
        imx_keep_uart_clocks = 1;

        return 0;
 }
+#ifndef MODULE
 __setup_param("earlycon", imx_keep_uart_earlycon,
              imx_keep_uart_clocks_param, 0);
 __setup_param("earlyprintk", imx_keep_uart_earlyprintk,
              imx_keep_uart_clocks_param, 0);

I feel not only the __setup_param, the whole logic of keep_uart_clocks
are not needed for Module case. Is it true?

Yes, but the 'keep_uart_clocks' is false by default and the function imx_keep_uart_clocks_param()
already has '__maybe_unused', it does NOT impact anything if it is for module build, so I did NOT
add the #ifndef check for them, just to keep code easy and clean.

Thanks,
Anson

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel