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authorHeiko Schocher <hs@denx.de>2014-07-18 06:07:19 +0200
committerStefano Babic <sbabic@denx.de>2014-07-23 12:25:42 +0200
commitb2f97cf279c54c51741539455116ec3393a871ea (patch)
tree8f193654de90dcd7b2f0928db887a38204b0f9bc /drivers/pwm/pwm-imx-util.c
parentaafe4020c1d0c0f989b68f839d66ffc66df6ab9e (diff)
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>
Diffstat (limited to 'drivers/pwm/pwm-imx-util.c')
-rw-r--r--drivers/pwm/pwm-imx-util.c73
1 files changed, 73 insertions, 0 deletions
diff --git a/drivers/pwm/pwm-imx-util.c b/drivers/pwm/pwm-imx-util.c
new file mode 100644
index 00000000000..f1d0b35d277
--- /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;
+}