Thread (38 messages) 38 messages, 4 authors, 2013-11-07
STALE4606d
Revisions (6)
  1. resend [diff vs current]
  2. v2 [diff vs current]
  3. v3 [diff vs current]
  4. v4 current
  5. v5 [diff vs current]
  6. v6 [diff vs current]

[PATCH v4 14/17] clk: at91: add PMC smd clock

From: Boris BREZILLON <hidden>
Date: 2013-10-11 11:48:08
Also in: linux-arm-kernel, lkml
Subsystem: arm port, arm/microchip (at91) soc support, common clk framework, the rest · Maintainers: Russell King, Nicolas Ferre, Alexandre Belloni, Claudiu Beznea, Michael Turquette, Stephen Boyd, Linus Torvalds

This patch adds at91 smd (Soft Modem) clock implementation using common clk
framework.

Not used by any driver right now.

Signed-off-by: Boris BREZILLON <redacted>
---
 arch/arm/mach-at91/Kconfig |    5 ++
 drivers/clk/at91/Makefile  |    1 +
 drivers/clk/at91/clk-smd.c |  173 ++++++++++++++++++++++++++++++++++++++++++++
 drivers/clk/at91/pmc.c     |    7 ++
 drivers/clk/at91/pmc.h     |    5 ++
 5 files changed, 191 insertions(+)
 create mode 100644 drivers/clk/at91/clk-smd.c
diff --git a/arch/arm/mach-at91/Kconfig b/arch/arm/mach-at91/Kconfig
index b76dc4c..97033f7 100644
--- a/arch/arm/mach-at91/Kconfig
+++ b/arch/arm/mach-at91/Kconfig
@@ -39,6 +39,9 @@ config AT91_SAM9G45_RESET
 config AT91_SAM9_TIME
 	bool
 
+config HAVE_AT91_SMD
+	bool
+
 config SOC_AT91SAM9
 	bool
 	select AT91_SAM9_TIME
@@ -85,6 +88,7 @@ config SOC_SAMA5D3
 	select HAVE_AT91_DBGU1
 	select AT91_USE_OLD_CLK
 	select HAVE_AT91_UTMI
+	select HAVE_AT91_SMD
 	select HAVE_AT91_USB_CLK
 	help
 	  Select this if you are using one of Atmel's SAMA5D3 family SoC.
@@ -157,6 +161,7 @@ config SOC_AT91SAM9X5
 	select SOC_AT91SAM9
 	select AT91_USE_OLD_CLK
 	select HAVE_AT91_UTMI
+	select HAVE_AT91_SMD
 	select HAVE_AT91_USB_CLK
 	help
 	  Select this if you are using one of Atmel's AT91SAM9x5 family SoC.
diff --git a/drivers/clk/at91/Makefile b/drivers/clk/at91/Makefile
index 61db058..0e92b71 100644
--- a/drivers/clk/at91/Makefile
+++ b/drivers/clk/at91/Makefile
@@ -9,3 +9,4 @@ obj-y += clk-system.o clk-peripheral.o
 obj-$(CONFIG_AT91_PROGRAMMABLE_CLOCKS)	+= clk-programmable.o
 obj-$(CONFIG_HAVE_AT91_UTMI)		+= clk-utmi.o
 obj-$(CONFIG_HAVE_AT91_USB_CLK)		+= clk-usb.o
+obj-$(CONFIG_HAVE_AT91_SMD)		+= clk-smd.o
diff --git a/drivers/clk/at91/clk-smd.c b/drivers/clk/at91/clk-smd.c
new file mode 100644
index 0000000..9f3fa39
--- /dev/null
+++ b/drivers/clk/at91/clk-smd.c
@@ -0,0 +1,173 @@
+/*
+ * drivers/clk/at91/clk-smd.c
+ *
+ *  Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>
+ *
+ * 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-provider.h>
+#include <linux/clkdev.h>
+#include <linux/clk/at91_pmc.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/io.h>
+
+#include "pmc.h"
+
+#define SMD_SOURCE_MAX		2
+
+#define SMD_DIV_SHIFT		8
+#define SMD_MAX_DIV		0xf
+
+struct at91sam9x5_clk_smd {
+	struct clk_hw hw;
+	struct at91_pmc *pmc;
+};
+
+#define to_at91sam9x5_clk_smd(hw) \
+	container_of(hw, struct at91sam9x5_clk_smd, hw)
+
+static unsigned long at91sam9x5_clk_smd_recalc_rate(struct clk_hw *hw,
+						    unsigned long parent_rate)
+{
+	u32 tmp;
+	u8 smddiv;
+	struct at91sam9x5_clk_smd *smd = to_at91sam9x5_clk_smd(hw);
+	struct at91_pmc *pmc = smd->pmc;
+
+	tmp = pmc_read(pmc, AT91_PMC_SMD);
+	smddiv = (tmp & AT91_PMC_SMD_DIV) >> SMD_DIV_SHIFT;
+	return parent_rate / (smddiv + 1);
+}
+
+static long at91sam9x5_clk_smd_round_rate(struct clk_hw *hw, unsigned long rate,
+					  unsigned long *parent_rate)
+{
+	unsigned long div;
+	unsigned long bestrate;
+	unsigned long tmp;
+
+	if (rate >= *parent_rate)
+		return *parent_rate;
+
+	div = *parent_rate / rate;
+	if (div > SMD_MAX_DIV)
+		return *parent_rate / (SMD_MAX_DIV + 1);
+
+	bestrate = *parent_rate / div;
+	tmp = *parent_rate / (div + 1);
+	if (bestrate - rate > rate - tmp)
+		bestrate = tmp;
+
+	return bestrate;
+}
+
+static int at91sam9x5_clk_smd_set_parent(struct clk_hw *hw, u8 index)
+{
+	u32 tmp;
+	struct at91sam9x5_clk_smd *smd = to_at91sam9x5_clk_smd(hw);
+	struct at91_pmc *pmc = smd->pmc;
+
+	if (index > 1)
+		return -EINVAL;
+	tmp = pmc_read(pmc, AT91_PMC_SMD) & ~AT91_PMC_SMDS;
+	if (index)
+		tmp |= AT91_PMC_SMDS;
+	pmc_write(pmc, AT91_PMC_SMD, tmp);
+	return 0;
+}
+
+static u8 at91sam9x5_clk_smd_get_parent(struct clk_hw *hw)
+{
+	struct at91sam9x5_clk_smd *smd = to_at91sam9x5_clk_smd(hw);
+	struct at91_pmc *pmc = smd->pmc;
+
+	return pmc_read(pmc, AT91_PMC_SMD) & AT91_PMC_SMDS;
+}
+
+static int at91sam9x5_clk_smd_set_rate(struct clk_hw *hw, unsigned long rate,
+				       unsigned long parent_rate)
+{
+	u32 tmp;
+	struct at91sam9x5_clk_smd *smd = to_at91sam9x5_clk_smd(hw);
+	struct at91_pmc *pmc = smd->pmc;
+	unsigned long div = parent_rate / rate;
+
+	if (parent_rate % rate || div < 1 || div > (SMD_MAX_DIV + 1))
+		return -EINVAL;
+	tmp = pmc_read(pmc, AT91_PMC_SMD) & ~AT91_PMC_SMD_DIV;
+	tmp |= (div - 1) << SMD_DIV_SHIFT;
+	pmc_write(pmc, AT91_PMC_SMD, tmp);
+
+	return 0;
+}
+
+static const struct clk_ops at91sam9x5_smd_ops = {
+	.recalc_rate = at91sam9x5_clk_smd_recalc_rate,
+	.round_rate = at91sam9x5_clk_smd_round_rate,
+	.get_parent = at91sam9x5_clk_smd_get_parent,
+	.set_parent = at91sam9x5_clk_smd_set_parent,
+	.set_rate = at91sam9x5_clk_smd_set_rate,
+};
+
+static struct clk * __init
+at91sam9x5_clk_register_smd(struct at91_pmc *pmc, const char *name,
+			    const char **parent_names, u8 num_parents)
+{
+	struct at91sam9x5_clk_smd *smd;
+	struct clk *clk = NULL;
+	struct clk_init_data init;
+
+	smd = kzalloc(sizeof(*smd), GFP_KERNEL);
+	if (!smd)
+		return ERR_PTR(-ENOMEM);
+
+	init.name = name;
+	init.ops = &at91sam9x5_smd_ops;
+	init.parent_names = parent_names;
+	init.num_parents = num_parents;
+	init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE;
+
+	smd->hw.init = &init;
+	smd->pmc = pmc;
+
+	clk = clk_register(NULL, &smd->hw);
+	if (IS_ERR(clk))
+		kfree(smd);
+
+	return clk;
+}
+
+void __init of_at91sam9x5_clk_smd_setup(struct device_node *np,
+					struct at91_pmc *pmc)
+{
+	struct clk *clk;
+	int i;
+	int num_parents;
+	const char *parent_names[SMD_SOURCE_MAX];
+	const char *name = np->name;
+
+	num_parents = of_count_phandle_with_args(np, "clocks", "#clock-cells");
+	if (num_parents <= 0 || num_parents >= SMD_SOURCE_MAX)
+		return;
+
+	for (i = 0; i < num_parents; i++) {
+		parent_names[i] = of_clk_get_parent_name(np, i);
+		if (!parent_names[i])
+			return;
+	}
+
+	of_property_read_string(np, "clock-output-names", &name);
+
+	clk = at91sam9x5_clk_register_smd(pmc, name, parent_names,
+					  num_parents);
+	if (IS_ERR(clk))
+		return;
+
+	of_clk_add_provider(np, of_clk_src_simple_get, clk);
+}
diff --git a/drivers/clk/at91/pmc.c b/drivers/clk/at91/pmc.c
index dc0b1b6..00a4a51 100644
--- a/drivers/clk/at91/pmc.c
+++ b/drivers/clk/at91/pmc.c
@@ -290,6 +290,13 @@ static const struct of_device_id pmc_clk_ids[] __initdata = {
 		.data = of_at91sam9x5_clk_usb_setup,
 	},
 #endif
+	/* SMD clock */
+#if defined(CONFIG_HAVE_AT91_SMD)
+	{
+		.compatible = "atmel,at91sam9x5-clk-smd",
+		.data = of_at91sam9x5_clk_smd_setup,
+	},
+#endif
 	{ /*sentinel*/ }
 };
 
diff --git a/drivers/clk/at91/pmc.h b/drivers/clk/at91/pmc.h
index eba7334..d0b8b38 100644
--- a/drivers/clk/at91/pmc.h
+++ b/drivers/clk/at91/pmc.h
@@ -105,4 +105,9 @@ extern void __init of_at91sam9n12_clk_usb_setup(struct device_node *np,
 						struct at91_pmc *pmc);
 #endif
 
+#if defined(CONFIG_HAVE_AT91_SMD)
+extern void __init of_at91sam9x5_clk_smd_setup(struct device_node *np,
+					       struct at91_pmc *pmc);
+#endif
+
 #endif /* __PMC_H_ */
-- 
1.7.9.5
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help