Re: [PATCH 2/2] clk: add artpec-6 pll1 clock driver

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On 02/17/2016 01:02 AM, Michael Turquette wrote:
Hi Lars,

Quoting Lars Persson (2016-02-11 08:01:04)
The PLL1 clock is a fixed-factor clock with factors derived from boot
mode pins. This driver is a simple wrapper to register the fixed
factor clock according to the pin settings.

Signed-off-by: Lars Persson <larper@xxxxxxxx>
---
  drivers/clk/Makefile      |  1 +
  drivers/clk/clk-artpec6.c | 70 +++++++++++++++++++++++++++++++++++++++++++++++
  2 files changed, 71 insertions(+)
  create mode 100644 drivers/clk/clk-artpec6.c

diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index b038e36..388f0cf 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -17,6 +17,7 @@ endif
# hardware specific clock types
  # please keep this section sorted lexicographically by file/directory path name
+obj-$(CONFIG_MACH_ARTPEC6)             += clk-artpec6.o
  obj-$(CONFIG_MACH_ASM9260)             += clk-asm9260.o
  obj-$(CONFIG_COMMON_CLK_AXI_CLKGEN)    += clk-axi-clkgen.o
  obj-$(CONFIG_ARCH_AXXIA)               += clk-axm5516.o
diff --git a/drivers/clk/clk-artpec6.c b/drivers/clk/clk-artpec6.c
new file mode 100644
index 0000000..3664c44
--- /dev/null
+++ b/drivers/clk/clk-artpec6.c
You mentioned having three drivers. Maybe consider putting this in
drivers/clk/axis?
Will be fixed in v2.

Continuing my questions from patch #1, should this clock be coupled with
other artpec6 clocks sharing the same clock controller?

@@ -0,0 +1,70 @@
+/*
+ * ARTPEC-6 clock initialization
+ *
+ * Copyright 2015 Axis Comunications AB.
+ *
+ * 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.
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/clkdev.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+
+static void __init of_artpec6_pll1_setup(struct device_node *np)
+{
+       void __iomem *devstat;
+       struct clk *clk;
+       const char *clk_name = np->name;
+       const char *parent_name;
+       u32 pll_mode, pll_m, pll_n;
+
+       parent_name = of_clk_get_parent_name(np, 0);
+
+       devstat = of_iomap(np, 0);
+       if (devstat == NULL) {
+               pr_err("error to ioremap DEVSTAT\n");
+               return;
+       }
+
+       /* DEVSTAT register contains PLL settings */
+       pll_mode = (readl(devstat) >> 6) & 3;
+       iounmap(devstat);
+
+       /*
+        * pll1 settings are designed for different DDR speeds using a fixed
+        * 50MHz external clock. However, a different external clock could be
+        * used on different boards.
+        * CPU clock is half the DDR clock.
+        */
+       switch (pll_mode) {
+       case 0: /* DDR3-2133 mode */
+               pll_m = 4;
+               pll_n = 85;
+               break;
+       case 1: /* DDR3-1866 mode */
+               pll_m = 6;
+               pll_n = 112;
+               break;
+       case 2: /* DDR3-1600 mode */
+               pll_m = 4;
+               pll_n = 64;
+               break;
+       case 3: /* DDR3-1333 mode */
+               pll_m = 8;
+               pll_n = 106;
+               break;
+       }
+       /* ext_clk is defined in device tree */
+       clk = clk_register_fixed_factor(NULL, clk_name, parent_name, 0,
+                       pll_n, pll_m);
+       if (IS_ERR(clk)) {
+               pr_err("%s not registered\n", clk_name);
+               return;
+       }
+       of_clk_add_provider(np, of_clk_src_simple_get, clk);
+}
+CLK_OF_DECLARE(artpec6_pll1, "axis,artpec6-pll1-clock", of_artpec6_pll1_setup);
Instead of using CLK_OF_DECLARE can you make this a platform_driver?
Will be fixed in v2.

Best regards,
Mike

--
2.1.4


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