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Message-Id: <20191011150546.9186-3-tbogendoerfer@suse.de>
Date: Fri, 11 Oct 2019 17:05:45 +0200
From: Thomas Bogendoerfer <tbogendoerfer@...e.de>
To: Joshua Kinard <kumba@...too.org>,
Alessandro Zummo <a.zummo@...ertech.it>,
Alexandre Belloni <alexandre.belloni@...tlin.com>,
linux-rtc@...r.kernel.org, linux-kernel@...r.kernel.org,
Ralf Baechle <ralf@...ux-mips.org>,
Paul Burton <paul.burton@...s.com>,
James Hogan <jhogan@...nel.org>, linux-mips@...r.kernel.org
Subject: [PATCH 3/3] rtc: ds1685: add indirect access method and remove plat_read/plat_write
Use of provided plat_read/plat_write introduces the problem of possible
different lifetime of rtc driver and plat_XXX function provider. As
this was only intended for SGI Octane (IP30) this patchset implements
a register indirect access method for IP30 and introduces an
access_type field in platform data to select how registers are
accessed. And since there are no resource allocating stunts needed
anymore it also gets rid of alloc_io_resources from platform data.
Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@...e.de>
---
arch/mips/sgi-ip32/ip32-platform.c | 2 +-
drivers/rtc/rtc-ds1685.c | 67 ++++++++++++++++++++++++--------------
include/linux/rtc/ds1685.h | 8 +++--
3 files changed, 48 insertions(+), 29 deletions(-)
diff --git a/arch/mips/sgi-ip32/ip32-platform.c b/arch/mips/sgi-ip32/ip32-platform.c
index 5a2a82148d8d..c3909bd8dd1a 100644
--- a/arch/mips/sgi-ip32/ip32-platform.c
+++ b/arch/mips/sgi-ip32/ip32-platform.c
@@ -115,7 +115,7 @@ ip32_rtc_platform_data[] = {
.bcd_mode = true,
.no_irq = false,
.uie_unsupported = false,
- .alloc_io_resources = true,
+ .access_type = ds1685_reg_direct,
.plat_prepare_poweroff = ip32_prepare_poweroff,
},
};
diff --git a/drivers/rtc/rtc-ds1685.c b/drivers/rtc/rtc-ds1685.c
index 349a8d1caca1..9c5d064ebb6c 100644
--- a/drivers/rtc/rtc-ds1685.c
+++ b/drivers/rtc/rtc-ds1685.c
@@ -59,6 +59,32 @@ ds1685_write(struct ds1685_priv *rtc, int reg, u8 value)
}
/* ----------------------------------------------------------------------- */
+/* Indirect read/write functions */
+
+/**
+ * ds1685_indir_read - read a value from an rtc register.
+ * @rtc: pointer to the ds1685 rtc structure.
+ * @reg: the register address to read.
+ */
+static u8
+ds1685_indir_read(struct ds1685_priv *rtc, int reg)
+{
+ writeb(reg, rtc->regs);
+ return readb(rtc->data);
+}
+
+/**
+ * ds1685_indir_write - write a value to an rtc register.
+ * @rtc: pointer to the ds1685 rtc structure.
+ * @reg: the register address to write.
+ * @value: value to write to the register.
+ */
+static void
+ds1685_indir_write(struct ds1685_priv *rtc, int reg, u8 value)
+{
+ writeb(reg, rtc->regs);
+ writeb(value, rtc->data);
+}
/* ----------------------------------------------------------------------- */
/* Inlined functions */
@@ -1062,16 +1088,25 @@ ds1685_rtc_probe(struct platform_device *pdev)
if (!rtc)
return -ENOMEM;
- /*
- * Allocate/setup any IORESOURCE_MEM resources, if required. Not all
- * platforms put the RTC in an easy-access place. Like the SGI Octane,
- * which attaches the RTC to a "ByteBus", hooked to a SuperIO chip
- * that sits behind the IOC3 PCI metadevice.
- */
- if (pdata->alloc_io_resources) {
+ /* Setup resources and access functions */
+ switch (pdata->access_type) {
+ case ds1685_reg_direct:
+ rtc->regs = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(rtc->regs))
+ return PTR_ERR(rtc->regs);
+ rtc->read = ds1685_read;
+ rtc->write = ds1685_write;
+ break;
+ case ds1685_reg_indirect:
rtc->regs = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(rtc->regs))
return PTR_ERR(rtc->regs);
+ rtc->data = devm_platform_ioremap_resource(pdev, 1);
+ if (IS_ERR(rtc->data))
+ return PTR_ERR(rtc->data);
+ rtc->read = ds1685_indir_read;
+ rtc->write = ds1685_indir_write;
+ break;
}
/* Get the register step size. */
@@ -1080,24 +1115,6 @@ ds1685_rtc_probe(struct platform_device *pdev)
else
rtc->regstep = 1;
- /* Platform read function, else default if mmio setup */
- if (pdata->plat_read)
- rtc->read = pdata->plat_read;
- else
- if (pdata->alloc_io_resources)
- rtc->read = ds1685_read;
- else
- return -ENXIO;
-
- /* Platform write function, else default if mmio setup */
- if (pdata->plat_write)
- rtc->write = pdata->plat_write;
- else
- if (pdata->alloc_io_resources)
- rtc->write = ds1685_write;
- else
- return -ENXIO;
-
/* Platform pre-shutdown function, if defined. */
if (pdata->plat_prepare_poweroff)
rtc->prepare_poweroff = pdata->plat_prepare_poweroff;
diff --git a/include/linux/rtc/ds1685.h b/include/linux/rtc/ds1685.h
index 101c7adc05a2..67ee9d20cc5a 100644
--- a/include/linux/rtc/ds1685.h
+++ b/include/linux/rtc/ds1685.h
@@ -42,6 +42,7 @@
struct ds1685_priv {
struct rtc_device *dev;
void __iomem *regs;
+ void __iomem *data;
u32 regstep;
int irq_num;
bool bcd_mode;
@@ -70,12 +71,13 @@ struct ds1685_rtc_platform_data {
const bool bcd_mode;
const bool no_irq;
const bool uie_unsupported;
- const bool alloc_io_resources;
- u8 (*plat_read)(struct ds1685_priv *, int);
- void (*plat_write)(struct ds1685_priv *, int, u8);
void (*plat_prepare_poweroff)(void);
void (*plat_wake_alarm)(void);
void (*plat_post_ram_clear)(void);
+ enum {
+ ds1685_reg_direct,
+ ds1685_reg_indirect
+ } access_type;
};
--
2.16.4
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