* [PATCH v3] mfd: atmel-hlcdc: implement config synchronization
@ 2015-07-07 17:16 Boris Brezillon
2015-07-17 11:56 ` Nicolas Ferre
2015-07-23 14:46 ` Lee Jones
0 siblings, 2 replies; 3+ messages in thread
From: Boris Brezillon @ 2015-07-07 17:16 UTC (permalink / raw
To: linux-arm-kernel
Some HLCDC registers cannot be written until the hardware has finished
applying the previous configuration request. If they are written while
an action is still in progress, the new configuration might be silently
ignored, resulting in unpredictable behavior.
Hide the config synchronization stuff in a regmap implementation and use
this implementation instead of the generic mmio one.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
---
Changes since v2:
- reword the commit message
Changes since v1:
- add a 100 usec timeout
---
drivers/mfd/atmel-hlcdc.c | 35 +++++++++++++++++++++++++++++++++--
1 file changed, 33 insertions(+), 2 deletions(-)
diff --git a/drivers/mfd/atmel-hlcdc.c b/drivers/mfd/atmel-hlcdc.c
index cfd58f4..04e01cc 100644
--- a/drivers/mfd/atmel-hlcdc.c
+++ b/drivers/mfd/atmel-hlcdc.c
@@ -18,6 +18,7 @@
*/
#include <linux/clk.h>
+#include <linux/iopoll.h>
#include <linux/mfd/atmel-hlcdc.h>
#include <linux/mfd/core.h>
#include <linux/module.h>
@@ -37,11 +38,41 @@ static const struct mfd_cell atmel_hlcdc_cells[] = {
},
};
+static int regmap_atmel_hlcdc_reg_write(void *context, unsigned int reg,
+ unsigned int val)
+{
+ void __iomem *regs = context;
+
+ if (reg <= ATMEL_HLCDC_DIS) {
+ u32 status;
+
+ readl_poll_timeout(regs + ATMEL_HLCDC_SR, status,
+ !(status & ATMEL_HLCDC_SIP), 1, 100);
+ }
+
+ writel(val, regs + reg);
+
+ return 0;
+}
+
+static int regmap_atmel_hlcdc_reg_read(void *context, unsigned int reg,
+ unsigned int *val)
+{
+ void __iomem *regs = context;
+
+ *val = readl(regs + reg);
+
+ return 0;
+}
+
static const struct regmap_config atmel_hlcdc_regmap_config = {
.reg_bits = 32,
.val_bits = 32,
.reg_stride = 4,
.max_register = ATMEL_HLCDC_REG_MAX,
+ .reg_write = regmap_atmel_hlcdc_reg_write,
+ .reg_read = regmap_atmel_hlcdc_reg_read,
+ .fast_io = true,
};
static int atmel_hlcdc_probe(struct platform_device *pdev)
@@ -82,8 +113,8 @@ static int atmel_hlcdc_probe(struct platform_device *pdev)
return PTR_ERR(hlcdc->slow_clk);
}
- hlcdc->regmap = devm_regmap_init_mmio(dev, regs,
- &atmel_hlcdc_regmap_config);
+ hlcdc->regmap = devm_regmap_init(dev, NULL, regs,
+ &atmel_hlcdc_regmap_config);
if (IS_ERR(hlcdc->regmap))
return PTR_ERR(hlcdc->regmap);
--
1.9.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* [PATCH v3] mfd: atmel-hlcdc: implement config synchronization
2015-07-07 17:16 [PATCH v3] mfd: atmel-hlcdc: implement config synchronization Boris Brezillon
@ 2015-07-17 11:56 ` Nicolas Ferre
2015-07-23 14:46 ` Lee Jones
1 sibling, 0 replies; 3+ messages in thread
From: Nicolas Ferre @ 2015-07-17 11:56 UTC (permalink / raw
To: linux-arm-kernel
Le 07/07/2015 19:16, Boris Brezillon a ?crit :
> Some HLCDC registers cannot be written until the hardware has finished
> applying the previous configuration request. If they are written while
> an action is still in progress, the new configuration might be silently
> ignored, resulting in unpredictable behavior.
>
> Hide the config synchronization stuff in a regmap implementation and use
> this implementation instead of the generic mmio one.
>
> Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Yes, that implements the needed behavior for these registers...
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Thanks. Bye,
> ---
> Changes since v2:
> - reword the commit message
>
> Changes since v1:
> - add a 100 usec timeout
> ---
> drivers/mfd/atmel-hlcdc.c | 35 +++++++++++++++++++++++++++++++++--
> 1 file changed, 33 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/mfd/atmel-hlcdc.c b/drivers/mfd/atmel-hlcdc.c
> index cfd58f4..04e01cc 100644
> --- a/drivers/mfd/atmel-hlcdc.c
> +++ b/drivers/mfd/atmel-hlcdc.c
> @@ -18,6 +18,7 @@
> */
>
> #include <linux/clk.h>
> +#include <linux/iopoll.h>
> #include <linux/mfd/atmel-hlcdc.h>
> #include <linux/mfd/core.h>
> #include <linux/module.h>
> @@ -37,11 +38,41 @@ static const struct mfd_cell atmel_hlcdc_cells[] = {
> },
> };
>
> +static int regmap_atmel_hlcdc_reg_write(void *context, unsigned int reg,
> + unsigned int val)
> +{
> + void __iomem *regs = context;
> +
> + if (reg <= ATMEL_HLCDC_DIS) {
> + u32 status;
> +
> + readl_poll_timeout(regs + ATMEL_HLCDC_SR, status,
> + !(status & ATMEL_HLCDC_SIP), 1, 100);
> + }
> +
> + writel(val, regs + reg);
> +
> + return 0;
> +}
> +
> +static int regmap_atmel_hlcdc_reg_read(void *context, unsigned int reg,
> + unsigned int *val)
> +{
> + void __iomem *regs = context;
> +
> + *val = readl(regs + reg);
> +
> + return 0;
> +}
> +
> static const struct regmap_config atmel_hlcdc_regmap_config = {
> .reg_bits = 32,
> .val_bits = 32,
> .reg_stride = 4,
> .max_register = ATMEL_HLCDC_REG_MAX,
> + .reg_write = regmap_atmel_hlcdc_reg_write,
> + .reg_read = regmap_atmel_hlcdc_reg_read,
> + .fast_io = true,
> };
>
> static int atmel_hlcdc_probe(struct platform_device *pdev)
> @@ -82,8 +113,8 @@ static int atmel_hlcdc_probe(struct platform_device *pdev)
> return PTR_ERR(hlcdc->slow_clk);
> }
>
> - hlcdc->regmap = devm_regmap_init_mmio(dev, regs,
> - &atmel_hlcdc_regmap_config);
> + hlcdc->regmap = devm_regmap_init(dev, NULL, regs,
> + &atmel_hlcdc_regmap_config);
> if (IS_ERR(hlcdc->regmap))
> return PTR_ERR(hlcdc->regmap);
>
>
--
Nicolas Ferre
^ permalink raw reply [flat|nested] 3+ messages in thread
* [PATCH v3] mfd: atmel-hlcdc: implement config synchronization
2015-07-07 17:16 [PATCH v3] mfd: atmel-hlcdc: implement config synchronization Boris Brezillon
2015-07-17 11:56 ` Nicolas Ferre
@ 2015-07-23 14:46 ` Lee Jones
1 sibling, 0 replies; 3+ messages in thread
From: Lee Jones @ 2015-07-23 14:46 UTC (permalink / raw
To: linux-arm-kernel
On Tue, 07 Jul 2015, Boris Brezillon wrote:
> Some HLCDC registers cannot be written until the hardware has finished
> applying the previous configuration request. If they are written while
> an action is still in progress, the new configuration might be silently
> ignored, resulting in unpredictable behavior.
>
> Hide the config synchronization stuff in a regmap implementation and use
> this implementation instead of the generic mmio one.
>
> Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
>
> ---
> Changes since v2:
> - reword the commit message
>
> Changes since v1:
> - add a 100 usec timeout
> ---
> drivers/mfd/atmel-hlcdc.c | 35 +++++++++++++++++++++++++++++++++--
> 1 file changed, 33 insertions(+), 2 deletions(-)
Applied, thanks.
> diff --git a/drivers/mfd/atmel-hlcdc.c b/drivers/mfd/atmel-hlcdc.c
> index cfd58f4..04e01cc 100644
> --- a/drivers/mfd/atmel-hlcdc.c
> +++ b/drivers/mfd/atmel-hlcdc.c
> @@ -18,6 +18,7 @@
> */
>
> #include <linux/clk.h>
> +#include <linux/iopoll.h>
> #include <linux/mfd/atmel-hlcdc.h>
> #include <linux/mfd/core.h>
> #include <linux/module.h>
> @@ -37,11 +38,41 @@ static const struct mfd_cell atmel_hlcdc_cells[] = {
> },
> };
>
> +static int regmap_atmel_hlcdc_reg_write(void *context, unsigned int reg,
> + unsigned int val)
> +{
> + void __iomem *regs = context;
> +
> + if (reg <= ATMEL_HLCDC_DIS) {
> + u32 status;
> +
> + readl_poll_timeout(regs + ATMEL_HLCDC_SR, status,
> + !(status & ATMEL_HLCDC_SIP), 1, 100);
> + }
> +
> + writel(val, regs + reg);
> +
> + return 0;
> +}
> +
> +static int regmap_atmel_hlcdc_reg_read(void *context, unsigned int reg,
> + unsigned int *val)
> +{
> + void __iomem *regs = context;
> +
> + *val = readl(regs + reg);
> +
> + return 0;
> +}
> +
> static const struct regmap_config atmel_hlcdc_regmap_config = {
> .reg_bits = 32,
> .val_bits = 32,
> .reg_stride = 4,
> .max_register = ATMEL_HLCDC_REG_MAX,
> + .reg_write = regmap_atmel_hlcdc_reg_write,
> + .reg_read = regmap_atmel_hlcdc_reg_read,
> + .fast_io = true,
> };
>
> static int atmel_hlcdc_probe(struct platform_device *pdev)
> @@ -82,8 +113,8 @@ static int atmel_hlcdc_probe(struct platform_device *pdev)
> return PTR_ERR(hlcdc->slow_clk);
> }
>
> - hlcdc->regmap = devm_regmap_init_mmio(dev, regs,
> - &atmel_hlcdc_regmap_config);
> + hlcdc->regmap = devm_regmap_init(dev, NULL, regs,
> + &atmel_hlcdc_regmap_config);
> if (IS_ERR(hlcdc->regmap))
> return PTR_ERR(hlcdc->regmap);
>
--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org ? Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog
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2015-07-17 11:56 ` Nicolas Ferre
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