[PATCH v3 1/6] clk: qcom: Add support for GDSCs

...

quoted

+
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/export.h>

?? Do you need this?

Maybe not, now that the EXPORT_SYMBOL() is gone.
I will remove it.

quoted

+#include <linux/jiffies.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include "gdsc.h"
+
+#define PWR_ON_MASK        BIT(31)
+#define EN_REST_WAIT_MASK    GENMASK(23, 20)
+#define EN_FEW_WAIT_MASK    GENMASK(19, 16)
+#define CLK_DIS_WAIT_MASK    GENMASK(15, 12)
+#define SW_OVERRIDE_MASK    BIT(2)
+#define HW_CONTROL_MASK        BIT(1)
+#define SW_COLLAPSE_MASK    BIT(0)
+
+/* Wait 2^n CXO cycles between all states. Here, n=2 (4 cycles). */
+#define EN_REST_WAIT_VAL    (0x2 << 20)
+#define EN_FEW_WAIT_VAL        (0x8 << 16)
+#define CLK_DIS_WAIT_VAL    (0x2 << 12)
+
+#define TIMEOUT_US        100
+
+static int gdsc_is_enabled(struct gdsc *sc)
+{
+    u32 val;
+    int ret;
+
+    ret = regmap_read(sc->regmap, sc->gdscr, &val);
+    if (ret)
+        return ret;

Line after this would be good.

quoted

+    return !!(val & PWR_ON_MASK);
+}
+
+static int gdsc_toggle_logic(struct gdsc *sc, bool en)
+{
+    int ret;
+    u32 val = en ? 0 : SW_COLLAPSE_MASK;
+    u32 check = en ? PWR_ON_MASK : 0;
+    unsigned long timeout;
+
+    ret = regmap_update_bits(sc->regmap, sc->gdscr, SW_COLLAPSE_MASK,
val);
+    if (ret)
+        return ret;
+
+    timeout = jiffies + usecs_to_jiffies(TIMEOUT_US);
+    do {
+        ret = regmap_read(sc->regmap, sc->gdscr, &val);
+        if (ret)
+            return ret;
+        if ((val & PWR_ON_MASK) == check)
+            return 0;
+    } while (time_before(jiffies, timeout));
+
+    ret =  regmap_read(sc->regmap, sc->gdscr, &val);
+    if (ret)
+        return ret;

New line here.

quoted

+    if ((val & PWR_ON_MASK) == check)
+        return 0;
+
+    return -ETIMEDOUT;
+}
+

...

quoted

+
+int gdsc_register(struct device *dev, struct gdsc **scs, size_t num,
+          struct regmap *regmap)
+{
+    int i, ret;
+    struct genpd_onecell_data *data;
+
+    if (!num || !scs || !dev || !dev->of_node)
+        return 0;

Should it not return -EINVAL here?

so we have gdsc_register() getting called from qcom_cc_really_probe()
and we might have devices with no gdscs as part of gcc. So the way to 
identify those is the num and scs aren't really initialized.
I should probably move this check into the common clk probe function
and not call gdsc_register() if these are not inited, and return a
-EINVAL for (!dev || !dev->of_node) here.

quoted

+
+    data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+    if (!data)
+        return -ENOMEM;
+
+    data->domains = devm_kzalloc(dev, sizeof(*data->domains) * num,
+                     GFP_KERNEL);
+    if (!data->domains)
+        return -ENOMEM;
+
+    data->num_domains = num;
+    for (i = 0; i < num; i++) {
+        if (!scs[i])
+            continue;
+        scs[i]->regmap = regmap;
+        ret = gdsc_init(scs[i]);
+        if (ret)
+            return ret;
+        data->domains[i] = &scs[i]->pd;
+    }

New line?

quoted

+    return of_genpd_add_provider_onecell(dev->of_node, data);
+}
+
+void gdsc_unregister(struct device *dev)
+{
+    of_genpd_del_provider(dev->of_node);
+}

diff --git a/drivers/clk/qcom/gdsc.h b/drivers/clk/qcom/gdsc.h
new file mode 100644
index 0000000..02e2990
--- /dev/null
+++ b/drivers/clk/qcom/gdsc.h

@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2015, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef __QCOM_GDSC_H__
+#define __QCOM_GDSC_H__
+
+#include <linux/pm_domain.h>
+
+struct regmap;
+
+/**
+ * struct gdsc - Globally Distributed Switch Controller
+ * @pd: generic power domain
+ * @regmap: regmap for MMIO accesses
+ * @gdscr: gsdc control register
+ */
+struct gdsc {
+    struct generic_pm_domain    pd;
+    struct regmap            *regmap;
+    unsigned int            gdscr;
+};
+
+#define domain_to_gdsc(domain) container_of(domain, struct gdsc, pd)
+
+#ifdef CONFIG_QCOM_GDSC
+int gdsc_register(struct device *, struct gdsc **, size_t n, struct

regmap *);
+void gdsc_unregister(struct device *);
+#else
+int gdsc_register(struct device *d, struct gdsc **g, size_t n, struct
regmap *r)

static inline here??? else it would result in muliple definitions?

It shouldn't result in mutiple defs, but static inline would be good.
I will fix it.

quoted

+{
+    return 0;

return -ENOSYS;

This should work once I put checks for non inited desc->num_gdscs as
part of  qcom_cc_really_probe().

Thanks for the review. I'll post a v4 with the changes.
regards,
Rajendra

quoted

+}
+
+void gdsc_unregister(struct device *d) {};

same static inline...
Braces should be in next line too.

quoted

+#endif /* CONFIG_QCOM_GDSC */
+#endif /* __QCOM_GDSC_H__ */

--srini

-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
hosted by The Linux Foundation