clk: versatile-icst: convert to use regmap

Instead of passing around register bases, pass around a regmap
in this driver. This refactoring make things so much easier when
we later want to manage an ICST that is part of a syscon.

Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: linux-clk@vger.kernel.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

diff --git a/drivers/clk/versatile/Kconfig b/drivers/clk/versatile/Kconfig
index fc50b62..e733385 100644 (file)
--- a/drivers/clk/versatile/Kconfig
+++ b/drivers/clk/versatile/Kconfig
@@ -1,6 +1,7 @@
 config COMMON_CLK_VERSATILE
        bool "Clock driver for ARM Reference designs"
        depends on ARCH_INTEGRATOR || ARCH_REALVIEW || ARCH_VEXPRESS || ARM64 || COMPILE_TEST
+       select REGMAP_MMIO
        ---help---
           Supports clocking on ARM Reference designs:
          - Integrator/AP and Integrator/CP

diff --git a/drivers/clk/versatile/clk-icst.c b/drivers/clk/versatile/clk-icst.c
index 08c5ee9..80e955a 100644 (file)
--- a/drivers/clk/versatile/clk-icst.c
+++ b/drivers/clk/versatile/clk-icst.c
@@ -19,9 +19,13 @@
 #include <linux/err.h>
 #include <linux/clk-provider.h>
 #include <linux/io.h>
+#include <linux/regmap.h>
 
 #include "clk-icst.h"
 
+/* Magic unlocking token used on all Versatile boards */
+#define VERSATILE_LOCK_VAL     0xA05F
+
 /**
  * struct clk_icst - ICST VCO clock wrapper
  * @hw: corresponding clock hardware entry
@@ -32,8 +36,9 @@
  */
 struct clk_icst {
        struct clk_hw hw;
-       void __iomem *vcoreg;
-       void __iomem *lockreg;
+       struct regmap *map;
+       u32 vcoreg_off;
+       u32 lockreg_off;
        struct icst_params *params;
        unsigned long rate;
 };
@@ -41,53 +46,67 @@ struct clk_icst {
 #define to_icst(_hw) container_of(_hw, struct clk_icst, hw)
 
 /**
- * vco_get() - get ICST VCO settings from a certain register
- * @vcoreg: register containing the VCO settings
+ * vco_get() - get ICST VCO settings from a certain ICST
+ * @icst: the ICST clock to get
+ * @vco: the VCO struct to return the value in
  */
-static struct icst_vco vco_get(void __iomem *vcoreg)
+static int vco_get(struct clk_icst *icst, struct icst_vco *vco)
 {
        u32 val;
-       struct icst_vco vco;
-
-       val = readl(vcoreg);
-       vco.v = val & 0x1ff;
-       vco.r = (val >> 9) & 0x7f;
-       vco.s = (val >> 16) & 03;
-       return vco;
+       int ret;
+
+       ret = regmap_read(icst->map, icst->vcoreg_off, &val);
+       if (ret)
+               return ret;
+       vco->v = val & 0x1ff;
+       vco->r = (val >> 9) & 0x7f;
+       vco->s = (val >> 16) & 03;
+       return 0;
 }
 
 /**
  * vco_set() - commit changes to an ICST VCO
- * @locreg: register to poke to unlock the VCO for writing
- * @vcoreg: register containing the VCO settings
- * @vco: ICST VCO parameters to commit
+ * @icst: the ICST clock to set
+ * @vco: the VCO struct to set the changes from
  */
-static void vco_set(void __iomem *lockreg,
-                       void __iomem *vcoreg,
-                       struct icst_vco vco)
+static int vco_set(struct clk_icst *icst, struct icst_vco vco)
 {
        u32 val;
+       int ret;
 
-       val = readl(vcoreg) & ~0x7ffff;
+       ret = regmap_read(icst->map, icst->vcoreg_off, &val);
+       if (ret)
+               return ret;
        val |= vco.v | (vco.r << 9) | (vco.s << 16);
 
        /* This magic unlocks the VCO so it can be controlled */
-       writel(0xa05f, lockreg);
-       writel(val, vcoreg);
+       ret = regmap_write(icst->map, icst->lockreg_off, VERSATILE_LOCK_VAL);
+       if (ret)
+               return ret;
+       ret = regmap_write(icst->map, icst->vcoreg_off, val);
+       if (ret)
+               return ret;
        /* This locks the VCO again */
-       writel(0, lockreg);
+       ret = regmap_write(icst->map, icst->lockreg_off, 0);
+       if (ret)
+               return ret;
+       return 0;
 }
 
-
 static unsigned long icst_recalc_rate(struct clk_hw *hw,
                                      unsigned long parent_rate)
 {
        struct clk_icst *icst = to_icst(hw);
        struct icst_vco vco;
+       int ret;
 
        if (parent_rate)
                icst->params->ref = parent_rate;
-       vco = vco_get(icst->vcoreg);
+       ret = vco_get(icst, &vco);
+       if (ret) {
+               pr_err("ICST: could not get VCO setting\n");
+               return 0;
+       }
        icst->rate = icst_hz(icst->params, vco);
        return icst->rate;
 }
@@ -112,8 +131,7 @@ static int icst_set_rate(struct clk_hw *hw, unsigned long rate,
                icst->params->ref = parent_rate;
        vco = icst_hz_to_vco(icst->params, rate);
        icst->rate = icst_hz(icst->params, vco);
-       vco_set(icst->lockreg, icst->vcoreg, vco);
-       return 0;
+       return vco_set(icst, vco);
 }
 
 static const struct clk_ops icst_ops = {
@@ -132,6 +150,11 @@ struct clk *icst_clk_register(struct device *dev,
        struct clk_icst *icst;
        struct clk_init_data init;
        struct icst_params *pclone;
+       struct regmap_config icst_regmap_conf = {
+               .reg_bits = 32,
+               .val_bits = 32,
+               .reg_stride = 4,
+       };
 
        icst = kzalloc(sizeof(struct clk_icst), GFP_KERNEL);
        if (!icst) {
@@ -151,10 +174,19 @@ struct clk *icst_clk_register(struct device *dev,
        init.flags = CLK_IS_ROOT;
        init.parent_names = (parent_name ? &parent_name : NULL);
        init.num_parents = (parent_name ? 1 : 0);
+       icst->map = regmap_init_mmio(dev, base, &icst_regmap_conf);
+       if (IS_ERR(icst->map)) {
+               int ret;
+
+               pr_err("could not initialize ICST regmap\n");
+               ret = PTR_ERR(icst->map);
+               kfree(icst);
+               return ERR_PTR(ret);
+       }
        icst->hw.init = &init;
        icst->params = pclone;
-       icst->vcoreg = base + desc->vco_offset;
-       icst->lockreg = base + desc->lock_offset;
+       icst->vcoreg_off = desc->vco_offset;
+       icst->lockreg_off = desc->lock_offset;
 
        clk = clk_register(dev, &icst->hw);
        if (IS_ERR(clk)) {