diff mbox series

[v1,11/12] nvmem: microchip-otpc: Enable main RC oscillator clock

Message ID 20240821105943.230281-12-ada@thorsis.com (mailing list archive)
State New, archived
Headers show
Series Microchip OTPC driver on SAM9X60 exposing UIDxR as additional nvmem device | expand

Commit Message

Alexander Dahl Aug. 21, 2024, 10:59 a.m. UTC
Without enabling that clock, initializing the packet list leads to a
read timeout on the first packet.

According to SAM9X60 datasheet (DS60001579G) section "23.4 Product
Dependencies" the clock must be enabled for reading and writing.

Tested on sam9x60-curiosity board.

Signed-off-by: Alexander Dahl <ada@thorsis.com>
---
 drivers/nvmem/microchip-otpc.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

Comments

kernel test robot Aug. 22, 2024, 3:57 p.m. UTC | #1
Hi Alexander,

kernel test robot noticed the following build warnings:

[auto build test WARNING on 47ac09b91befbb6a235ab620c32af719f8208399]

url:    https://github.com/intel-lab-lkp/linux/commits/Alexander-Dahl/nvmem-microchip-otpc-Avoid-writing-a-write-only-register/20240821-193942
base:   47ac09b91befbb6a235ab620c32af719f8208399
patch link:    https://lore.kernel.org/r/20240821105943.230281-12-ada%40thorsis.com
patch subject: [PATCH v1 11/12] nvmem: microchip-otpc: Enable main RC oscillator clock
config: x86_64-buildonly-randconfig-001-20240822 (https://download.01.org/0day-ci/archive/20240822/202408222300.BEv0hBO5-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240822/202408222300.BEv0hBO5-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202408222300.BEv0hBO5-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/nvmem/microchip-otpc.c:61: warning: Function parameter or struct member 'clk' not described in 'mchp_otpc'


vim +61 drivers/nvmem/microchip-otpc.c

98830350d3fc82 Claudiu Beznea 2022-07-06  47  
98830350d3fc82 Claudiu Beznea 2022-07-06  48  /**
98830350d3fc82 Claudiu Beznea 2022-07-06  49   * struct mchp_otpc - OTPC private data structure
98830350d3fc82 Claudiu Beznea 2022-07-06  50   * @base: base address
98830350d3fc82 Claudiu Beznea 2022-07-06  51   * @dev: struct device pointer
98830350d3fc82 Claudiu Beznea 2022-07-06  52   * @packets: list of packets in OTP memory
98830350d3fc82 Claudiu Beznea 2022-07-06  53   * @npackets: number of packets in OTP memory
98830350d3fc82 Claudiu Beznea 2022-07-06  54   */
98830350d3fc82 Claudiu Beznea 2022-07-06  55  struct mchp_otpc {
98830350d3fc82 Claudiu Beznea 2022-07-06  56  	void __iomem *base;
98830350d3fc82 Claudiu Beznea 2022-07-06  57  	struct device *dev;
1acc431703527a Alexander Dahl 2024-08-21  58  	struct clk *clk;
98830350d3fc82 Claudiu Beznea 2022-07-06  59  	struct list_head packets;
98830350d3fc82 Claudiu Beznea 2022-07-06  60  	u32 npackets;
98830350d3fc82 Claudiu Beznea 2022-07-06 @61  };
98830350d3fc82 Claudiu Beznea 2022-07-06  62
Claudiu Beznea Aug. 24, 2024, 3:53 p.m. UTC | #2
On 21.08.2024 13:59, Alexander Dahl wrote:
> Without enabling that clock, initializing the packet list leads to a
> read timeout on the first packet.
> 
> According to SAM9X60 datasheet (DS60001579G) section "23.4 Product
> Dependencies" the clock must be enabled for reading and writing.
> 
> Tested on sam9x60-curiosity board.
> 
> Signed-off-by: Alexander Dahl <ada@thorsis.com>
> ---
>  drivers/nvmem/microchip-otpc.c | 11 +++++++++++
>  1 file changed, 11 insertions(+)
> 
> diff --git a/drivers/nvmem/microchip-otpc.c b/drivers/nvmem/microchip-otpc.c
> index a80535c3d162..047ca5ac6407 100644
> --- a/drivers/nvmem/microchip-otpc.c
> +++ b/drivers/nvmem/microchip-otpc.c
> @@ -8,6 +8,7 @@
>   */
>  
>  #include <linux/bitfield.h>
> +#include <linux/clk.h>
>  #include <linux/dev_printk.h>
>  #include <linux/iopoll.h>
>  #include <linux/module.h>
> @@ -54,6 +55,7 @@
>  struct mchp_otpc {
>  	void __iomem *base;
>  	struct device *dev;
> +	struct clk *clk;
>  	struct list_head packets;
>  	u32 npackets;
>  };
> @@ -272,6 +274,15 @@ static int mchp_otpc_probe(struct platform_device *pdev)
>  	if (IS_ERR(otpc->base))
>  		return PTR_ERR(otpc->base);
>  
> +	// NOTE: Maybe make this optional, especially if sama7g5 testing

Looking though DS, on SAMA7G5 the clock here should be MCK0. I think it
should be added for SAMA7G5, too, with a fixes tag.

> +	// shows the clock is not required there?

Use C style comments /* comment */

> +	otpc->clk = devm_clk_get_enabled(&pdev->dev, "main_rc_osc");

Maybe name it "bus-clk", "bus" or something otpc specific.

> +	if (IS_ERR(otpc->clk)) {
> +		dev_err(&pdev->dev, "Error (%ld) getting clock!\n",
> +			PTR_ERR(otpc->clk));
> +		return PTR_ERR(otpc->clk);

return dev_err_probe().

> +	}
> +
>  	reg = readl_relaxed(otpc->base + MCHP_OTPC_WPSR);
>  	if (reg)
>  		dev_warn(&pdev->dev,
diff mbox series

Patch

diff --git a/drivers/nvmem/microchip-otpc.c b/drivers/nvmem/microchip-otpc.c
index a80535c3d162..047ca5ac6407 100644
--- a/drivers/nvmem/microchip-otpc.c
+++ b/drivers/nvmem/microchip-otpc.c
@@ -8,6 +8,7 @@ 
  */
 
 #include <linux/bitfield.h>
+#include <linux/clk.h>
 #include <linux/dev_printk.h>
 #include <linux/iopoll.h>
 #include <linux/module.h>
@@ -54,6 +55,7 @@ 
 struct mchp_otpc {
 	void __iomem *base;
 	struct device *dev;
+	struct clk *clk;
 	struct list_head packets;
 	u32 npackets;
 };
@@ -272,6 +274,15 @@  static int mchp_otpc_probe(struct platform_device *pdev)
 	if (IS_ERR(otpc->base))
 		return PTR_ERR(otpc->base);
 
+	// NOTE: Maybe make this optional, especially if sama7g5 testing
+	// shows the clock is not required there?
+	otpc->clk = devm_clk_get_enabled(&pdev->dev, "main_rc_osc");
+	if (IS_ERR(otpc->clk)) {
+		dev_err(&pdev->dev, "Error (%ld) getting clock!\n",
+			PTR_ERR(otpc->clk));
+		return PTR_ERR(otpc->clk);
+	}
+
 	reg = readl_relaxed(otpc->base + MCHP_OTPC_WPSR);
 	if (reg)
 		dev_warn(&pdev->dev,