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/README b/README
index 4ac73996983add08d11a15875fa203a5f8fd3393..a35b92c889036a04e5c06d202c69f7c0fcb172a3 100644 (file)
--- a/README
+++ b/README
@@ -1377,6 +1377,10 @@ The following options need to be configured:
                        CONFIG_SH_ETHER_CACHE_WRITEBACK
                        If this option is set, the driver enables cache flush.
 
+- PWM Support:
+               CONFIG_PWM_IMX
+               Support for PWM modul on the imx6.
+
 - TPM Support:
                CONFIG_TPM
                Support TPM devices.

diff --git a/drivers/Makefile b/drivers/Makefile
index b23076f614a0fdac02c17cb19c3dcb45bcd90a68..b22b109404ebef8506e8b8b8f064e8bd487768ad 100644 (file)
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -15,3 +15,4 @@ obj-y += video/
 obj-y += watchdog/
 obj-$(CONFIG_QE) += qe/
 obj-y += memory/
+obj-y += pwm/

diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
new file mode 100644 (file)
index 0000000..c0c4883
--- /dev/null
+++ b/drivers/pwm/Makefile
@@ -0,0 +1,13 @@
+#
+# (C) Copyright 2006
+# Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+#
+# (C) Copyright 2001
+# Erik Theisen, Wave 7 Optics, etheisen@mindspring.com.
+#
+# SPDX-License-Identifier:     GPL-2.0+
+#
+
+#ccflags-y += -DDEBUG
+
+obj-$(CONFIG_PWM_IMX) += pwm-imx.o pwm-imx-util.o

diff --git a/drivers/pwm/pwm-imx-util.c b/drivers/pwm/pwm-imx-util.c
new file mode 100644 (file)
index 0000000..f1d0b35
--- /dev/null
+++ b/drivers/pwm/pwm-imx-util.c
@@ -0,0 +1,73 @@
+/*
+ * (C) Copyright 2014
+ * Heiko Schocher, DENX Software Engineering, hs@denx.de.
+ *
+ * Basic support for the pwm modul on imx6.
+ *
+ * Based on linux:drivers/pwm/pwm-imx.c
+ * from
+ * Sascha Hauer <s.hauer@pengutronix.de>
+ *
+ * SPDX-License-Identifier:    GPL-2.0
+ */
+
+#include <common.h>
+#include <div64.h>
+#include <asm/arch/imx-regs.h>
+
+/* pwm_id from 0..3 */
+struct pwm_regs *pwm_id_to_reg(int pwm_id)
+{
+       switch (pwm_id) {
+       case 0:
+               return (struct pwm_regs *)PWM1_BASE_ADDR;
+               break;
+       case 1:
+               return (struct pwm_regs *)PWM2_BASE_ADDR;
+               break;
+       case 2:
+               return (struct pwm_regs *)PWM3_BASE_ADDR;
+               break;
+       case 3:
+               return (struct pwm_regs *)PWM4_BASE_ADDR;
+               break;
+       default:
+               printf("unknown pwm_id: %d\n", pwm_id);
+               break;
+       }
+       return NULL;
+}
+
+int pwm_imx_get_parms(int period_ns, int duty_ns, unsigned long *period_c,
+                     unsigned long *duty_c, unsigned long *prescale)
+{
+       unsigned long long c;
+
+       /*
+        * we have not yet a clock framework for imx6, so add the clock
+        * value here as a define. Replace it when we have the clock
+        * framework.
+        */
+       c = CONFIG_IMX6_PWM_PER_CLK;
+       c = c * period_ns;
+       do_div(c, 1000000000);
+       *period_c = c;
+
+       *prescale = *period_c / 0x10000 + 1;
+
+       *period_c /= *prescale;
+       c = (unsigned long long)(*period_c * duty_ns);
+       do_div(c, period_ns);
+       *duty_c = c;
+
+       /*
+        * according to imx pwm RM, the real period value should be
+        * PERIOD value in PWMPR plus 2.
+        */
+       if (*period_c > 2)
+               *period_c -= 2;
+       else
+               *period_c = 0;
+
+       return 0;
+}

diff --git a/drivers/pwm/pwm-imx-util.h b/drivers/pwm/pwm-imx-util.h
new file mode 100644 (file)
index 0000000..45465c4
--- /dev/null
+++ b/drivers/pwm/pwm-imx-util.h
@@ -0,0 +1,16 @@
+/*
+ * (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
+ */
+
+#ifndef _pwm_imx_util_h_
+#define _pwm_imx_util_h_
+
+struct pwm_regs *pwm_id_to_reg(int pwm_id);
+int pwm_imx_get_parms(int period_ns, int duty_ns, unsigned long *period_c,
+                     unsigned long *duty_c, unsigned long *prescale);
+#endif

diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c
new file mode 100644 (file)
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);
+}