[PATCH V2] clk: palmas: add clock driver for palmas
Laxman Dewangan
ldewangan at nvidia.com
Mon Oct 7 10:05:51 EDT 2013
Palmas devices has two clock output CLK32K_KG and CLK32K_KG_AUDIO
which can be nebale/disable through software.
Add clock driver support for the Palmas 32k clocks.
Signed-off-by: Laxman Dewangan <ldewangan at nvidia.com>
---
Changes from V1:
- Call prepare if the clk is needed for boot-enable or sleep control.
- change is_enabled to is_prepared.
- Added ops palmas_clks_recalc_rate.
- Added of_clk_add_provider().
.../devicetree/bindings/clock/clk-palmas.txt | 45 +++
drivers/clk/Kconfig | 7 +
drivers/clk/Makefile | 2 +
drivers/clk/clk-palmas.c | 336 ++++++++++++++++++++
4 files changed, 390 insertions(+), 0 deletions(-)
create mode 100644 Documentation/devicetree/bindings/clock/clk-palmas.txt
create mode 100644 drivers/clk/clk-palmas.c
diff --git a/Documentation/devicetree/bindings/clock/clk-palmas.txt b/Documentation/devicetree/bindings/clock/clk-palmas.txt
new file mode 100644
index 0000000..c247538
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/clk-palmas.txt
@@ -0,0 +1,45 @@
+* Palmas 32KHz clocks *
+
+Palmas device has two clock output pins for 32KHz, KG and KG_AUDIO.
+
+This binding uses the common clock binding ./clock-bindings.txt.
+
+Clock 32KHz KG is output 0 of the driver and clock 32KHz is output 1.
+
+Required properties:
+- compatible : shall be "ti,palmas-clk".
+- #clock-cells : from common clock binding; shall be set to 1.
+
+Optional subnode:
+ The clock node has optional subnode to provide the init configuration of
+ clocks like boot enable, sleep control.
+
+ The subnode name is fixed and it should be
+ clk32k_kg for the 32KHz KG clock.
+ clk32k_kg_audio for the 32KHz KG_AUDIO clock.
+
+ Optional subnode properties:
+ ti,clock-boot-enable: Enable clock at the time of booting.
+ ti,external-sleep-control: The clock is enable/disabled by state
+ of external enable input pins ENABLE, ENABLE2 and NSLEEP.
+ The valid value for the external pins are:
+ 1 for ENABLE1
+ 2 for ENABLE2
+ 3 for NSLEEP.
+ Option 0 or missing this property means the clock is
+ enabled/disabled via register access and these pins do
+ not have any control.
+
+Example:
+ clock {
+ compatible = "ti,palmas-clk";
+ #clock-cells = <1>;
+ clk32k_kg {
+ ti,clock-boot-enable;
+ ti,external-sleep-control = <3>;
+ };
+
+ clk32k_kg_audio {
+ ti,clock-boot-enable;
+ };
+ };
diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
index 279407a..6b8c233 100644
--- a/drivers/clk/Kconfig
+++ b/drivers/clk/Kconfig
@@ -93,6 +93,13 @@ config CLK_PPC_CORENET
This adds the clock driver support for Freescale PowerPC corenet
platforms using common clock framework.
+config COMMON_CLK_PALMAS
+ tristate "Clock driver for TI Palmas devices"
+ depends on MFD_PALMAS
+ ---help---
+ This driver supports TI Palmas devices 32KHz output KG and KG_AUDIO
+ using common clock framework.
+
endmenu
source "drivers/clk/mvebu/Kconfig"
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index 7b11106..f168ff7 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -43,3 +43,5 @@ obj-$(CONFIG_COMMON_CLK_SI5351) += clk-si5351.o
obj-$(CONFIG_COMMON_CLK_S2MPS11) += clk-s2mps11.o
obj-$(CONFIG_CLK_TWL6040) += clk-twl6040.o
obj-$(CONFIG_CLK_PPC_CORENET) += clk-ppc-corenet.o
+obj-$(CONFIG_COMMON_CLK_PALMAS) += clk-palmas.o
+obj-y += clk-test.o
diff --git a/drivers/clk/clk-palmas.c b/drivers/clk/clk-palmas.c
new file mode 100644
index 0000000..804c76e
--- /dev/null
+++ b/drivers/clk/clk-palmas.c
@@ -0,0 +1,336 @@
+/*
+ * Clock driver for Palmas device.
+ *
+ * Copyright (c) 2013, NVIDIA Corporation.
+ *
+ * Author: Laxman Dewangan <ldewangan at nvidia.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 version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any kind,
+ * whether express or implied; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * 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., 59 Temple Place, Suite 330, Boston, MA
+ * 02111-1307, USA
+ */
+
+#include <linux/clk.h>
+#include <linux/clkdev.h>
+#include <linux/clk-provider.h>
+#include <linux/mfd/palmas.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+enum PALMAS_CLOCK32K {
+ PALMAS_CLOCK32KG,
+ PALMAS_CLOCK32KG_AUDIO,
+
+ /* Last entry */
+ PALMAS_CLOCK32K_NR,
+};
+
+struct palmas_clks;
+
+struct palmas_clk32k_desc {
+ const char *clk_name;
+ unsigned int control_reg;
+ unsigned int enable_mask;
+ unsigned int sleep_mask;
+ unsigned int sleep_reqstr_id;
+};
+
+struct palmas_clock_info {
+ struct clk *clk;
+ struct clk_hw hw;
+ struct palmas_clk32k_desc *clk_desc;
+ struct palmas_clks *palmas_clk;
+ int ext_control_pin;
+ bool boot_enable;
+};
+
+struct palmas_clks {
+ struct device *dev;
+ struct palmas *palmas;
+ struct clk_onecell_data clk_data;
+ struct palmas_clock_info clk_info[PALMAS_CLOCK32K_NR];
+};
+
+static struct palmas_clk32k_desc palmas_clk32k_descs[] = {
+ {
+ .clk_name = "clk32k_kg",
+ .control_reg = PALMAS_CLK32KG_CTRL,
+ .enable_mask = PALMAS_CLK32KG_CTRL_MODE_ACTIVE,
+ .sleep_mask = PALMAS_CLK32KG_CTRL_MODE_SLEEP,
+ .sleep_reqstr_id = PALMAS_EXTERNAL_REQSTR_ID_CLK32KG,
+ }, {
+ .clk_name = "clk32k_kg_audio",
+ .control_reg = PALMAS_CLK32KGAUDIO_CTRL,
+ .enable_mask = PALMAS_CLK32KG_CTRL_MODE_ACTIVE,
+ .sleep_mask = PALMAS_CLK32KG_CTRL_MODE_SLEEP,
+ .sleep_reqstr_id = PALMAS_EXTERNAL_REQSTR_ID_CLK32KGAUDIO,
+ },
+};
+
+static inline struct palmas_clock_info *to_palmas_clks_info(struct clk_hw *hw)
+{
+ return container_of(hw, struct palmas_clock_info, hw);
+}
+
+static unsigned long palmas_clks_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ return 32768;
+}
+
+static int palmas_clks_prepare(struct clk_hw *hw)
+{
+ struct palmas_clock_info *cinfo = to_palmas_clks_info(hw);
+ struct palmas_clks *palmas_clks = cinfo->palmas_clk;
+ int ret;
+
+ ret = palmas_update_bits(palmas_clks->palmas, PALMAS_RESOURCE_BASE,
+ cinfo->clk_desc->control_reg,
+ cinfo->clk_desc->enable_mask,
+ cinfo->clk_desc->enable_mask);
+ if (ret < 0)
+ dev_err(palmas_clks->dev, "Reg 0x%02x update failed, %d\n",
+ cinfo->clk_desc->control_reg, ret);
+
+ return ret;
+}
+
+static void palmas_clks_unprepare(struct clk_hw *hw)
+{
+ struct palmas_clock_info *cinfo = to_palmas_clks_info(hw);
+ struct palmas_clks *palmas_clks = cinfo->palmas_clk;
+ int ret;
+
+ /*
+ * Clock can be disabled through external pin if it is externally
+ * controlled.
+ */
+ if (cinfo->ext_control_pin)
+ return;
+
+ ret = palmas_update_bits(palmas_clks->palmas, PALMAS_RESOURCE_BASE,
+ cinfo->clk_desc->control_reg,
+ cinfo->clk_desc->enable_mask, 0);
+ if (ret < 0)
+ dev_err(palmas_clks->dev, "Reg 0x%02x update failed, %d\n",
+ cinfo->clk_desc->control_reg, ret);
+
+}
+
+static int palmas_clks_is_prepared(struct clk_hw *hw)
+{
+ struct palmas_clock_info *cinfo = to_palmas_clks_info(hw);
+ struct palmas_clks *palmas_clks = cinfo->palmas_clk;
+ int ret;
+ u32 val;
+
+ if (cinfo->ext_control_pin)
+ return 1;
+
+ ret = palmas_read(palmas_clks->palmas, PALMAS_RESOURCE_BASE,
+ cinfo->clk_desc->control_reg, &val);
+ if (ret < 0) {
+ dev_err(palmas_clks->dev, "Reg 0x%02x read failed, %d\n",
+ cinfo->clk_desc->control_reg, ret);
+ return ret;
+ }
+ return !!(val & cinfo->clk_desc->enable_mask);
+}
+
+static struct clk_ops palmas_clks_ops = {
+ .prepare = palmas_clks_prepare,
+ .unprepare = palmas_clks_unprepare,
+ .is_prepared = palmas_clks_is_prepared,
+ .recalc_rate = palmas_clks_recalc_rate,
+};
+
+static struct clk_init_data palmas_clks_hw_init[PALMAS_CLOCK32K_NR] = {
+ [PALMAS_CLOCK32KG] = {
+ .name = "clk32k_kg",
+ .ops = &palmas_clks_ops,
+ .flags = CLK_IS_ROOT | CLK_IGNORE_UNUSED,
+ },
+ [PALMAS_CLOCK32KG_AUDIO] = {
+ .name = "clk32k_kg_audio",
+ .ops = &palmas_clks_ops,
+ .flags = CLK_IS_ROOT | CLK_IGNORE_UNUSED,
+ },
+};
+
+static int palmas_clks_get_clk_data(struct platform_device *pdev,
+ struct palmas_clks *palmas_clks)
+{
+ struct device_node *node = pdev->dev.of_node;
+ struct device_node *child;
+ struct palmas_clock_info *cinfo;
+ unsigned int prop;
+ int ret;
+ int i;
+
+ for (i = 0; i < PALMAS_CLOCK32K_NR; ++i) {
+ child = of_get_child_by_name(node,
+ palmas_clk32k_descs[i].clk_name);
+ if (!child)
+ continue;
+
+ cinfo = &palmas_clks->clk_info[i];
+ cinfo->boot_enable = of_property_read_bool(child,
+ "ti,clock-boot-enable");
+ ret = of_property_read_u32(child, "ti,external-sleep-control",
+ &prop);
+ if (!ret) {
+ switch (prop) {
+ case 1:
+ prop = PALMAS_EXT_CONTROL_ENABLE1;
+ break;
+ case 2:
+ prop = PALMAS_EXT_CONTROL_ENABLE2;
+ break;
+ case 3:
+ prop = PALMAS_EXT_CONTROL_NSLEEP;
+ break;
+ default:
+ WARN_ON(1);
+ dev_warn(&pdev->dev,
+ "%s: Invalid ext control option: %u\n",
+ child->name, prop);
+ prop = 0;
+ break;
+ }
+ cinfo->ext_control_pin = prop;
+ }
+ }
+
+ return 0;
+}
+
+static int palmas_clks_init_configure(struct palmas_clock_info *cinfo)
+{
+ struct palmas_clks *palmas_clks = cinfo->palmas_clk;
+ int ret;
+
+ if (cinfo->boot_enable || cinfo->ext_control_pin) {
+ ret = clk_prepare(cinfo->clk);
+ if (ret < 0) {
+ dev_err(palmas_clks->dev,
+ "Clock prep failed, %d\n", ret);
+ return ret;
+ }
+ }
+
+ ret = palmas_update_bits(palmas_clks->palmas, PALMAS_RESOURCE_BASE,
+ cinfo->clk_desc->control_reg,
+ cinfo->clk_desc->sleep_mask, 0);
+ if (ret < 0) {
+ dev_err(palmas_clks->dev, "Reg 0x%02x update failed, %d\n",
+ cinfo->clk_desc->control_reg, ret);
+ return ret;
+ }
+
+ if (cinfo->ext_control_pin) {
+ ret = palmas_ext_control_req_config(palmas_clks->palmas,
+ cinfo->clk_desc->sleep_reqstr_id,
+ cinfo->ext_control_pin, true);
+ if (ret < 0) {
+ dev_err(palmas_clks->dev,
+ "Ext config for %s failed, %d\n",
+ cinfo->clk_desc->clk_name, ret);
+ return ret;
+ }
+ }
+
+ return ret;
+}
+
+static int palmas_clks_probe(struct platform_device *pdev)
+{
+ struct palmas *palmas = dev_get_drvdata(pdev->dev.parent);
+ struct palmas_clock_info *cinfo;
+ struct palmas_clks *palmas_clks;
+ struct clk *clk;
+ int i, ret;
+
+ palmas_clks = devm_kzalloc(&pdev->dev, sizeof(*palmas_clks),
+ GFP_KERNEL);
+ if (!palmas_clks)
+ return -ENOMEM;
+
+ palmas_clks->clk_data.clks = devm_kzalloc(&pdev->dev,
+ PALMAS_CLOCK32K_NR * sizeof(palmas_clks->clk_data.clks),
+ GFP_KERNEL);
+ if (!palmas_clks->clk_data.clks)
+ return -ENOMEM;
+
+ palmas_clks_get_clk_data(pdev, palmas_clks);
+ platform_set_drvdata(pdev, palmas_clks);
+
+ palmas_clks->dev = &pdev->dev;
+ palmas_clks->palmas = palmas;
+
+ for (i = 0; i < PALMAS_CLOCK32K_NR; i++) {
+ cinfo = &palmas_clks->clk_info[i];
+ cinfo->clk_desc = &palmas_clk32k_descs[i];
+ cinfo->hw.init = &palmas_clks_hw_init[i];
+ cinfo->palmas_clk = palmas_clks;
+ clk = devm_clk_register(&pdev->dev, &cinfo->hw);
+ if (IS_ERR(clk)) {
+ ret = PTR_ERR(clk);
+ dev_err(&pdev->dev, "Fail to register clock %s, %d\n",
+ palmas_clk32k_descs[i].clk_name, ret);
+ return ret;
+ }
+
+ cinfo->clk = clk;
+ palmas_clks->clk_data.clks[i] = clk;
+ palmas_clks->clk_data.clk_num++;
+ palmas_clks_init_configure(cinfo);
+ }
+
+ ret = of_clk_add_provider(pdev->dev.of_node, of_clk_src_simple_get,
+ &palmas_clks->clk_data);
+ if (ret < 0)
+ dev_err(&pdev->dev, "Fail to add clock driver, %d\n", ret);
+ return ret;
+}
+
+static int palmas_clks_remove(struct platform_device *pdev)
+{
+ of_clk_del_provider(pdev->dev.of_node);
+ return 0;
+}
+
+static struct of_device_id of_palmas_clks_match_tbl[] = {
+ { .compatible = "ti,palmas-clk", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, of_palmas_clks_match_tbl);
+
+static struct platform_driver palmas_clks_driver = {
+ .driver = {
+ .name = "palmas-clk",
+ .owner = THIS_MODULE,
+ .of_match_table = of_palmas_clks_match_tbl,
+ },
+ .probe = palmas_clks_probe,
+ .remove = palmas_clks_remove,
+};
+
+module_platform_driver(palmas_clks_driver);
+
+MODULE_DESCRIPTION("Clock driver for Palmas Series Devices");
+MODULE_ALIAS("platform:palmas-clk");
+MODULE_AUTHOR("Laxman Dewangan <ldewangan at nvidia.com>");
+MODULE_LICENSE("GPL v2");
--
1.7.1.1
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