pwm, imx6: add support for pwm modul on imx6

add basic support for the pwm modul found on imx6.
Pieces of this code are based on linux code from drivers/pwm/pwm-imx.c
Commit "cd3de83f1476 Linux 3.16-rc4"

Signed-off-by: Heiko Schocher <hs@denx.de>
Acked-by: Stefano Babic <sbabic@denx.de>
Cc: Wolfgang Denk <wd@denx.de>
diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c
new file mode 100644
index 0000000..40bf027
--- /dev/null
+++ b/drivers/pwm/pwm-imx.c
@@ -0,0 +1,59 @@
+/*
+ * (C) Copyright 2014
+ * Heiko Schocher, DENX Software Engineering, hs@denx.de.
+ *
+ * Basic support for the pwm modul on imx6.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <div64.h>
+#include <pwm.h>
+#include <asm/arch/imx-regs.h>
+#include <asm/io.h>
+#include "pwm-imx-util.h"
+
+int pwm_init(int pwm_id, int div, int invert)
+{
+	struct pwm_regs *pwm = (struct pwm_regs *)pwm_id_to_reg(pwm_id);
+
+	writel(0, &pwm->ir);
+	return 0;
+}
+
+int pwm_config(int pwm_id, int duty_ns, int period_ns)
+{
+	struct pwm_regs *pwm = (struct pwm_regs *)pwm_id_to_reg(pwm_id);
+	unsigned long period_cycles, duty_cycles, prescale;
+	u32 cr;
+
+	pwm_imx_get_parms(period_ns, duty_ns, &period_cycles, &duty_cycles,
+			  &prescale);
+
+	cr = PWMCR_PRESCALER(prescale) |
+		PWMCR_DOZEEN | PWMCR_WAITEN |
+		PWMCR_DBGEN | PWMCR_CLKSRC_IPG_HIGH;
+
+	writel(cr, &pwm->cr);
+	/* set duty cycles */
+	writel(duty_cycles, &pwm->sar);
+	/* set period cycles */
+	writel(period_cycles, &pwm->pr);
+	return 0;
+}
+
+int pwm_enable(int pwm_id)
+{
+	struct pwm_regs *pwm = (struct pwm_regs *)pwm_id_to_reg(pwm_id);
+
+	setbits_le32(&pwm->cr, PWMCR_EN);
+	return 0;
+}
+
+void pwm_disable(int pwm_id)
+{
+	struct pwm_regs *pwm = (struct pwm_regs *)pwm_id_to_reg(pwm_id);
+
+	clrbits_le32(&pwm->cr, PWMCR_EN);
+}