diff mbox

[v2,02/13] clk: davinci - add PSC clock driver

Message ID 1348683037-9705-3-git-send-email-m-karicheri2@ti.com (mailing list archive)
State Changes Requested
Headers show

Commit Message

Murali Karicheri Sept. 26, 2012, 6:10 p.m. UTC
This is the driver for the Power Sleep Controller (PSC) hardware
found on DM SoCs as well Keystone SoCs (c6x). This driver borrowed
code from arch/arm/mach-davinci/psc.c and implemented the driver
as per common clock provider API. The PSC module is responsible for
enabling/disabling the Power Domain and Clock domain for different IPs
present in the SoC. The driver is configured through the platform
data structure struct clk_davinci_psc_data.

Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
diff mbox

Patch

diff --git a/drivers/clk/davinci/clk-davinci-psc.c b/drivers/clk/davinci/clk-davinci-psc.c
new file mode 100644
index 0000000..b7aa332
--- /dev/null
+++ b/drivers/clk/davinci/clk-davinci-psc.c
@@ -0,0 +1,197 @@ 
+/*
+ * PSC clk driver for DaVinci devices
+ *
+ * Copyright (C) 2006-2012 Texas Instruments.
+ * Copyright (C) 2008-2009 Deep Root Systems, LLC
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <linux/platform_data/clk-davinci-psc.h>
+
+/* PSC register offsets */
+#define EPCPR		0x070
+#define PTCMD		0x120
+#define PTSTAT		0x128
+#define PDSTAT		0x200
+#define PDCTL		0x300
+#define MDSTAT		0x800
+#define MDCTL		0xA00
+
+/* PSC module states */
+#define PSC_STATE_SWRSTDISABLE	0
+#define PSC_STATE_SYNCRST	1
+#define PSC_STATE_DISABLE	2
+#define PSC_STATE_ENABLE	3
+
+#define MDSTAT_STATE_MASK	0x3f
+#define PDSTAT_STATE_MASK	0x1f
+#define MDCTL_FORCE		BIT(31)
+#define PDCTL_NEXT		BIT(0)
+#define PDCTL_EPCGOOD		BIT(8)
+
+/* PSC flags */
+#define PSC_SWRSTDISABLE	BIT(0) /* Disable state is SwRstDisable */
+#define PSC_FORCE		BIT(1) /* Force module state transtition */
+#define PSC_HAS_EXT_POWER_CNTL	BIT(2) /* PSC has external power control
+					* available (for DM6446 SoC) */
+/**
+ * struct clk_psc - DaVinci PSC clock
+ * @hw: clk_hw for the psc
+ * @psc_data: PSC driver specific data
+ * @lock: Spinlock used by the driver
+ */
+struct clk_psc {
+	struct clk_hw hw;
+	struct clk_davinci_psc_data *psc_data;
+	spinlock_t *lock;
+};
+
+#define to_clk_psc(_hw) container_of(_hw, struct clk_psc, hw)
+
+/* Enable or disable a PSC domain */
+static void clk_psc_config(void __iomem *base, unsigned int domain,
+		unsigned int id, bool enable, u32 flags)
+{
+	u32 epcpr, ptcmd, ptstat, pdstat, pdctl, mdstat, mdctl;
+	u32 next_state = PSC_STATE_ENABLE;
+	void __iomem *psc_base = base;
+
+	if (!enable) {
+		if (flags & PSC_SWRSTDISABLE)
+			next_state = PSC_STATE_SWRSTDISABLE;
+		else
+			next_state = PSC_STATE_DISABLE;
+	}
+
+	mdctl = __raw_readl(psc_base + MDCTL + 4 * id);
+	mdctl &= ~MDSTAT_STATE_MASK;
+	mdctl |= next_state;
+	if (flags & PSC_FORCE)
+		mdctl |= MDCTL_FORCE;
+	__raw_writel(mdctl, psc_base + MDCTL + 4 * id);
+
+	pdstat = __raw_readl(psc_base + PDSTAT + 4 * domain);
+	if ((pdstat & PDSTAT_STATE_MASK) == 0) {
+		pdctl = __raw_readl(psc_base + PDCTL + 4 * domain);
+		pdctl |= PDCTL_NEXT;
+		__raw_writel(pdctl, psc_base + PDCTL + 4 * domain);
+
+		ptcmd = 1 << domain;
+		__raw_writel(ptcmd, psc_base + PTCMD);
+
+		if (flags & PSC_HAS_EXT_POWER_CNTL) {
+			do {
+				epcpr = __raw_readl(psc_base + EPCPR);
+			} while ((((epcpr >> domain) & 1) == 0));
+		}
+
+		pdctl = __raw_readl(psc_base + PDCTL + 4 * domain);
+		pdctl |= 0x100;
+		__raw_writel(pdctl, psc_base + PDCTL + 4 * domain);
+
+		pdctl = __raw_readl(psc_base + PDCTL + 4 * domain);
+		pdctl |= PDCTL_EPCGOOD;
+		__raw_writel(pdctl, psc_base + PDCTL + 4 * domain);
+	} else {
+		ptcmd = 1 << domain;
+		__raw_writel(ptcmd, psc_base + PTCMD);
+	}
+
+	do {
+		ptstat = __raw_readl(psc_base + PTSTAT);
+	} while (!(((ptstat >> domain) & 1) == 0));
+
+	do {
+		mdstat = __raw_readl(psc_base + MDSTAT + 4 * id);
+	} while (!((mdstat & MDSTAT_STATE_MASK) == next_state));
+}
+
+static int clk_psc_is_enabled(struct clk_hw *hw)
+{
+	struct clk_psc *psc = to_clk_psc(hw);
+	struct clk_davinci_psc_data *psc_data = psc->psc_data;
+	u32 mdstat;
+
+	mdstat = __raw_readl(psc_data->base + MDSTAT + 4 * psc_data->lpsc);
+	/* if clocked, state can be "Enable" or "SyncReset" */
+	return (mdstat & BIT(12)) ? 1 : 0;
+}
+
+static int clk_psc_enable(struct clk_hw *hw)
+{
+	struct clk_psc *psc = to_clk_psc(hw);
+	struct clk_davinci_psc_data *psc_data = psc->psc_data;
+	unsigned long flags = 0;
+
+	if (psc->lock)
+		spin_lock_irqsave(psc->lock, flags);
+
+	clk_psc_config(psc_data->base, psc_data->domain, psc_data->lpsc,
+			1, psc_data->psc_flags);
+
+	if (psc->lock)
+		spin_unlock_irqrestore(psc->lock, flags);
+
+	return 0;
+}
+
+static void clk_psc_disable(struct clk_hw *hw)
+{
+	struct clk_psc *psc = to_clk_psc(hw);
+	struct clk_davinci_psc_data *psc_data = psc->psc_data;
+	unsigned long flags = 0;
+
+	if (psc->lock)
+		spin_lock_irqsave(psc->lock, flags);
+
+	clk_psc_config(psc_data->base, psc_data->domain, psc_data->lpsc,
+			0, psc_data->psc_flags);
+
+	if (psc->lock)
+		spin_unlock_irqrestore(psc->lock, flags);
+}
+
+static const struct clk_ops clk_psc_ops = {
+	.enable = clk_psc_enable,
+	.disable = clk_psc_disable,
+	.is_enabled = clk_psc_is_enabled,
+};
+
+struct clk *clk_register_davinci_psc(struct device *dev, const char *name,
+			const char *parent_name,
+			struct clk_davinci_psc_data *psc_data,
+			spinlock_t *lock)
+{
+	struct clk_init_data init;
+	struct clk_psc *psc;
+	struct clk *clk;
+
+	psc = kzalloc(sizeof(*psc), GFP_KERNEL);
+	if (!psc)
+		return ERR_PTR(-ENOMEM);
+
+	init.name = name;
+	init.ops = &clk_psc_ops;
+	init.flags = psc_data->flags;
+	init.parent_names = (parent_name ? &parent_name : NULL);
+	init.num_parents = (parent_name ? 1 : 0);
+
+	psc->psc_data = psc_data;
+	psc->lock = lock;
+	psc->hw.init = &init;
+
+	clk = clk_register(NULL, &psc->hw);
+	if (IS_ERR(clk))
+		kfree(psc);
+
+	return clk;
+}
diff --git a/include/linux/platform_data/clk-davinci-psc.h b/include/linux/platform_data/clk-davinci-psc.h
new file mode 100644
index 0000000..b805f72
--- /dev/null
+++ b/include/linux/platform_data/clk-davinci-psc.h
@@ -0,0 +1,53 @@ 
+/*
+ *  DaVinci Power & Sleep Controller (PSC) clk driver platform data
+ *
+ *  Copyright (C) 2006-2012 Texas Instruments.
+ *
+ *  This program is free software; you can redistribute  it and/or modify it
+ *  under  the terms of  the GNU General  Public License as published by the
+ *  Free Software Foundation;  either version 2 of the  License, or (at your
+ *  option) any later version.
+ *
+ *  THIS  SOFTWARE  IS PROVIDED   ``AS  IS'' AND   ANY  EXPRESS OR IMPLIED
+ *  WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
+ *  NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT, INDIRECT,
+ *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF
+ *  USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT
+ *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ *  You should have received a copy of the  GNU General Public License along
+ *  with this program; if not, write  to the Free Software Foundation, Inc.,
+ *  675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+#ifndef __CLK_DAVINCI_PSC_H
+#define __CLK_DAVINCI_PSC_H
+
+/* PSC flags */
+/* Disable state is SwRstDisable */
+#define CLK_DAVINCI_PSC_SWRSTDISABLE	BIT(0)
+/* Force module state transtition */
+#define CLK_DAVINCI_PSC_FORCE		BIT(1)
+/* PSC has external power control available (for DM6446 SoC) */
+#define CLK_DAVINCI_PSC_HAS_EXT_POWER_CNTL	BIT(2)
+struct clk_davinci_psc_data {
+	/* base address of the PSC */
+	void __iomem *base;
+	/* framework flags */
+	u32	flags;
+	/* psc specific flags */
+	u32	psc_flags;
+	u8	lpsc;
+	u8	gpsc;
+	u8	domain;
+};
+
+extern struct clk *clk_register_davinci_psc(struct device *dev,
+			const char *name, const char *parent_name,
+			struct clk_davinci_psc_data *psc_data,
+			spinlock_t *lock);
+#endif /* __CLK_DAVINCI_PSC_H */