CLK: clk-twl6040: Initial clock driver for OMAP4+ McPDM fclk clock

On OMAP4+ platforms the functional clock for the McPDM IP is suplied by
the twl6040 codec (bit clock on the PDM bus).
This common clock driver for twl6040 will register the mcpdm_fclk clock to
be used by the McPDM driver to make sure that the needed clocks are
available when needed.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

1 files changed, 126 insertions, 0 deletions

diff --git a/drivers/clk/clk-twl6040.c b/drivers/clk/clk-twl6040.c
new file mode 100644
index 000000000000..f4a3389c3d09
--- /dev/null
+++ b/drivers/clk/clk-twl6040.c
@@ -0,0 +1,126 @@
+/*
+* TWL6040 clock module driver for OMAP4 McPDM functional clock
+*
+* Copyright (C) 2012 Texas Instruments Inc.
+* Peter Ujfalusi <peter.ujfalusi@ti.com>
+*
+* 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.
+*
+* This program is distributed in the hope that it will be useful, but
+* WITHOUT ANY WARRANTY; 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., 51 Franklin St, Fifth Floor, Boston, MA
+* 02110-1301 USA
+*
+*/
+
+#include <linux/clk.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/twl6040.h>
+#include <linux/clk-provider.h>
+
+struct twl6040_clk {
+        struct twl6040 *twl6040;
+        struct device *dev;
+        struct clk_hw mcpdm_fclk;
+        struct clk *clk;
+        int enabled;
+};
+
+static int twl6040_bitclk_is_enabled(struct clk_hw *hw)
+{
+        struct twl6040_clk *twl6040_clk = container_of(hw, struct twl6040_clk,
+                                                       mcpdm_fclk);
+        return twl6040_clk->enabled;
+}
+
+static int twl6040_bitclk_prepare(struct clk_hw *hw)
+{
+        struct twl6040_clk *twl6040_clk = container_of(hw, struct twl6040_clk,
+                                                       mcpdm_fclk);
+        int ret;
+
+        ret = twl6040_power(twl6040_clk->twl6040, 1);
+        if (!ret)
+                twl6040_clk->enabled = 1;
+
+        return ret;
+}
+
+static void twl6040_bitclk_unprepare(struct clk_hw *hw)
+{
+        struct twl6040_clk *twl6040_clk = container_of(hw, struct twl6040_clk,
+                                                       mcpdm_fclk);
+        int ret;
+
+        ret = twl6040_power(twl6040_clk->twl6040, 0);
+        if (!ret)
+                twl6040_clk->enabled = 0;
+}
+
+static const struct clk_ops twl6040_mcpdm_ops = {
+        .is_enabled = twl6040_bitclk_is_enabled,
+        .prepare = twl6040_bitclk_prepare,
+        .unprepare = twl6040_bitclk_unprepare,
+};
+
+static struct clk_init_data wm831x_clkout_init = {
+        .name = "mcpdm_fclk",
+        .ops = &twl6040_mcpdm_ops,
+        .flags = CLK_IS_ROOT,
+};
+
+static int __devinit twl6040_clk_probe(struct platform_device *pdev)
+{
+        struct twl6040 *twl6040 = dev_get_drvdata(pdev->dev.parent);
+        struct twl6040_clk *clkdata;
+
+        clkdata = devm_kzalloc(&pdev->dev, sizeof(*clkdata), GFP_KERNEL);
+        if (!clkdata)
+                return -ENOMEM;
+
+        clkdata->dev = &pdev->dev;
+        clkdata->twl6040 = twl6040;
+
+        clkdata->mcpdm_fclk.init = &wm831x_clkout_init;
+        clkdata->clk = clk_register(&pdev->dev, &clkdata->mcpdm_fclk);
+        if (!clkdata->clk)
+                return -EINVAL;
+
+        dev_set_drvdata(&pdev->dev, clkdata);
+
+        return 0;
+}
+
+static int __devexit twl6040_clk_remove(struct platform_device *pdev)
+{
+        struct twl6040_clk *clkdata = dev_get_drvdata(&pdev->dev);
+
+        clk_unregister(clkdata->clk);
+
+        return 0;
+}
+
+static struct platform_driver twl6040_clk_driver = {
+        .driver = {
+                .name = "twl6040-clk",
+                .owner = THIS_MODULE,
+        },
+        .probe = twl6040_clk_probe,
+        .remove = __devexit_p(twl6040_clk_remove),
+};
+
+module_platform_driver(twl6040_clk_driver);
+
+MODULE_DESCRIPTION("TWL6040 clock driver for McPDM functional clock");
+MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
+MODULE_ALIAS("platform:twl6040-clk");
+MODULE_LICENSE("GPL");