Re: [PATCH 1/5] drivers: soc: add support for exynos SROM driver

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




Hi Krzysztof,

Sorry for delay in reply, as I got busy in some other official assignments and could not take this series further at that time.

On Wednesday 27 May 2015 05:22 PM, Krzysztof Kozlowski wrote:
W dniu 29.04.2015 o 17:38, Pankaj Dubey pisze:
This patch adds Exynos SROM controller driver which will handle
save restore of SROM registers during S2R.

Change-Id: Iaddaaebc1d7090c9889e948e68e886519562c43c

Please remove it.

Will do it.


Signed-off-by: Pankaj Dubey <pankaj.dubey@xxxxxxxxxxx>
---
  drivers/soc/Kconfig               |   1 +
  drivers/soc/Makefile              |   1 +
  drivers/soc/samsung/Kconfig       |  14 ++++
  drivers/soc/samsung/Makefile      |   1 +
  drivers/soc/samsung/exynos-srom.c | 142 ++++++++++++++++++++++++++++++++++++++
  drivers/soc/samsung/exynos-srom.h |  51 ++++++++++++++
  6 files changed, 210 insertions(+)
  create mode 100644 drivers/soc/samsung/Kconfig
  create mode 100644 drivers/soc/samsung/Makefile
  create mode 100644 drivers/soc/samsung/exynos-srom.c
  create mode 100644 drivers/soc/samsung/exynos-srom.h

diff --git a/drivers/soc/Kconfig b/drivers/soc/Kconfig
index 76d6bd4..c3abfbe 100644
--- a/drivers/soc/Kconfig
+++ b/drivers/soc/Kconfig
@@ -1,6 +1,7 @@
  menu "SOC (System On Chip) specific Drivers"

  source "drivers/soc/qcom/Kconfig"
+source "drivers/soc/samsung/Kconfig"
  source "drivers/soc/ti/Kconfig"
  source "drivers/soc/versatile/Kconfig"

diff --git a/drivers/soc/Makefile b/drivers/soc/Makefile
index 063113d..620366f 100644
--- a/drivers/soc/Makefile
+++ b/drivers/soc/Makefile
@@ -3,6 +3,7 @@
  #

  obj-$(CONFIG_ARCH_QCOM)		+= qcom/
+obj-$(CONFIG_SOC_SAMSUNG)	+= samsung/
  obj-$(CONFIG_ARCH_TEGRA)	+= tegra/
  obj-$(CONFIG_SOC_TI)		+= ti/
  obj-$(CONFIG_PLAT_VERSATILE)	+= versatile/
diff --git a/drivers/soc/samsung/Kconfig b/drivers/soc/samsung/Kconfig
new file mode 100644
index 0000000..b6fa4e6
--- /dev/null
+++ b/drivers/soc/samsung/Kconfig
@@ -0,0 +1,14 @@
+#
+# SAMSUNG SoC drivers
+#
+menu "Samsung SOC driver support"
+
+config SOC_SAMSUNG
+	bool

Any reason for not using menuconfig?


For one of my Exynos PMU patchset [1] this suggestion came from Russel King, not to use user-visible sysmbol if not required. [1]: http://lists.infradead.org/pipermail/linux-arm-kernel/2014-November/304451.html

+
+config EXYNOS_SROM
+	bool
+	depends on ARM && ARCH_EXYNOS
+	select SOC_BUS

Why we need to select SOC_BUS?


We do not need it, will modify.

+
+endmenu
diff --git a/drivers/soc/samsung/Makefile b/drivers/soc/samsung/Makefile
new file mode 100644
index 0000000..9c554d5
--- /dev/null
+++ b/drivers/soc/samsung/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_EXYNOS_SROM)	+= exynos-srom.o
diff --git a/drivers/soc/samsung/exynos-srom.c b/drivers/soc/samsung/exynos-srom.c
new file mode 100644
index 0000000..8aae762
--- /dev/null
+++ b/drivers/soc/samsung/exynos-srom.c
@@ -0,0 +1,142 @@
+/*
+ * Copyright (c) 2015 Samsung Electronics Co., Ltd.
+ *	      http://www.samsung.com/
+ *
+ * EXYNOS - SROM Controller support
+ * Author: Pankaj Dubey <pankaj.dubey@xxxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include "exynos-srom.h"
+
+static void __iomem *exynos_srom_base;
+
+static unsigned long exynos_srom_offsets[] = {

static const

+	/* SROM side */
+	S5P_SROM_BW,
+	S5P_SROM_BC0,
+	S5P_SROM_BC1,
+	S5P_SROM_BC2,
+	S5P_SROM_BC3,
+};
+
+/**
+ * struct exynos_srom_reg_dump: register dump of SROM Controller registers.
+ * @offset: srom register offset from the controller base address.
+ * @value: the value to be register at offset.

Maybe:
@value: the value of register under the offset


OK.

+ */
+struct exynos_srom_reg_dump {
+	u32     offset;
+	u32     value;
+};
+
+static struct exynos_srom_reg_dump *exynos_srom_regs;
+
+static struct exynos_srom_reg_dump *exynos_srom_alloc_reg_dump(
+		const unsigned long *rdump,
+		unsigned long nr_rdump)
+{
+	struct exynos_srom_reg_dump *rd;
+	unsigned int i;
+
+	rd = kcalloc(nr_rdump, sizeof(*rd), GFP_KERNEL);
+	if (!rd)
+		return NULL;
+
+	for (i = 0; i < nr_rdump; ++i)
+		rd[i].offset = rdump[i];
+
+	return rd;
+}
+
+static void exynos_srom_save(void __iomem *base,
+				    struct exynos_srom_reg_dump *rd,
+				    unsigned int num_regs)
+{
+	for (; num_regs > 0; --num_regs, ++rd)
+		rd->value = readl(base + rd->offset);
+
+}
+
+static void exynos_srom_restore(void __iomem *base,
+				      const struct exynos_srom_reg_dump *rd,
+				      unsigned int num_regs)
+{
+	for (; num_regs > 0; --num_regs, ++rd)
+		writel(rd->value, base + rd->offset);
+
+}
+
+static const struct of_device_id of_exynos_srom_ids[] = {
+	{
+		.compatible	= "samsung,exynos-srom",
+	},
+	{},
+};
+
+static int exynos_srom_probe(struct platform_device *pdev)
+{
+	struct device_node *np;
+	struct device *dev = &pdev->dev;
+
+	np = dev->of_node;
+	exynos_srom_base = of_iomap(np, 0);
+
+	if (!exynos_srom_base)
+		return PTR_ERR(exynos_srom_base);

This looks wrong. If this is NULL, do not convert it to ERR. What will
be the value of PTR_ERR(NULL)?


Ok will handle it properly.

+
+	exynos_srom_regs = exynos_srom_alloc_reg_dump(exynos_srom_offsets,
+			sizeof(exynos_srom_offsets));

if (NULL) then what? Have you tested the error paths in the probe?


I have not tested this for error path, will take care.

+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int exynos_srom_suspend(struct device *dev)
+{
+	exynos_srom_save(exynos_srom_base, exynos_srom_regs,
+				ARRAY_SIZE(exynos_srom_offsets));
+
+	return 0;
+}
+
+static int exynos_srom_resume(struct device *dev)
+{
+	exynos_srom_restore(exynos_srom_base, exynos_srom_regs,
+				ARRAY_SIZE(exynos_srom_offsets));
+
+	return 0;
+}
+
+static const struct dev_pm_ops exynos_srom_dev_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(exynos_srom_suspend, exynos_srom_resume)
+};
+
+#define DEV_PM_OPS	(&exynos_srom_dev_pm_ops)
+#else
+#define DEV_PM_OPS	NULL
+#endif /* CONFIG_PM_SLEEP */

That look like an old code. Please use SIMPLE_DEV_PM_OPS unless there is
a reason not to.


Thanks for suggestion, will update accordingly.

+
+static struct platform_driver exynos_srom_driver = {
+	.probe = exynos_srom_probe,
+	.driver = {
+		.name = "exynos-srom",
+		.of_match_table = of_exynos_srom_ids,
+		.pm = DEV_PM_OPS,
+	},
+};
+
+static int __init exynos_srom_init(void)
+{
+	return platform_driver_register(&exynos_srom_driver);
+}
+device_initcall(exynos_srom_init);
diff --git a/drivers/soc/samsung/exynos-srom.h b/drivers/soc/samsung/exynos-srom.h
new file mode 100644
index 0000000..e6ee438
--- /dev/null
+++ b/drivers/soc/samsung/exynos-srom.h
@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) 2015 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com
+ *
+ * Exynos SROMC register definitions
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+*/
+
+#ifndef __SAMSUNG_REGS_SROM_H
+#define __SAMSUNG_REGS_SROM_H __FILE__

The double-inclusion protection looks different than file path and name.
Please make it similar.


OK.

+#define S5P_SROMREG(x)		(x)
+
+#define S5P_SROM_BW		S5P_SROMREG(0x0)
+#define S5P_SROM_BC0		S5P_SROMREG(0x4)
+#define S5P_SROM_BC1		S5P_SROMREG(0x8)
+#define S5P_SROM_BC2		S5P_SROMREG(0xc)
+#define S5P_SROM_BC3		S5P_SROMREG(0x10)
+#define S5P_SROM_BC4		S5P_SROMREG(0x14)
+#define S5P_SROM_BC5		S5P_SROMREG(0x18)
+
+/* one register BW holds 4 x 4-bit packed settings for NCS0 - NCS3 */
+
+#define S5P_SROM_BW__DATAWIDTH__SHIFT		0
+#define S5P_SROM_BW__ADDRMODE__SHIFT		1
+#define S5P_SROM_BW__WAITENABLE__SHIFT		2
+#define S5P_SROM_BW__BYTEENABLE__SHIFT		3
+
+#define S5P_SROM_BW__CS_MASK			0xf
+
+#define S5P_SROM_BW__NCS0__SHIFT		0
+#define S5P_SROM_BW__NCS1__SHIFT		4
+#define S5P_SROM_BW__NCS2__SHIFT		8
+#define S5P_SROM_BW__NCS3__SHIFT		12
+#define S5P_SROM_BW__NCS4__SHIFT		16
+#define S5P_SROM_BW__NCS5__SHIFT		20
+
+/* applies to same to BCS0 - BCS3 */
+
+#define S5P_SROM_BCX__PMC__SHIFT		0
+#define S5P_SROM_BCX__TACP__SHIFT		4
+#define S5P_SROM_BCX__TCAH__SHIFT		8
+#define S5P_SROM_BCX__TCOH__SHIFT		12
+#define S5P_SROM_BCX__TACC__SHIFT		16
+#define S5P_SROM_BCX__TCOS__SHIFT		24
+#define S5P_SROM_BCX__TACS__SHIFT		28

s/S5P/EXYNOS/

OK.

Thanks,
Pankaj Dubey

+
+#endif /* __SAMSUNG_REGS_SROM_H */



--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Device Tree Compilter]     [Device Tree Spec]     [Linux Driver Backports]     [Video for Linux]     [Linux USB Devel]     [Linux PCI Devel]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Yosemite Backpacking]
  Powered by Linux