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Message-Id: <20240822111631.544886-2-prabhakar.mahadev-lad.rj@bp.renesas.com>
Date: Thu, 22 Aug 2024 12:16:30 +0100
From: Prabhakar <prabhakar.csengg@...il.com>
To: Geert Uytterhoeven <geert+renesas@...der.be>,
Michael Turquette <mturquette@...libre.com>,
Stephen Boyd <sboyd@...nel.org>
Cc: linux-renesas-soc@...r.kernel.org,
linux-clk@...r.kernel.org,
linux-kernel@...r.kernel.org,
Prabhakar <prabhakar.csengg@...il.com>,
Biju Das <biju.das.jz@...renesas.com>,
Fabrizio Castro <fabrizio.castro.jz@...esas.com>,
Lad Prabhakar <prabhakar.mahadev-lad.rj@...renesas.com>
Subject: [PATCH v2 1/2] clk: renesas: rzv2h-cpg: Add support for dynamic switching divider clocks
From: Lad Prabhakar <prabhakar.mahadev-lad.rj@...renesas.com>
Add support for dynamic switching divider clocks.
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@...renesas.com>
---
v1->v2
- Dropped DDIV_DIVCTL_WIDTH
- width is now extracted from conf
- Updated DDIV_GET_* macros
- Now doing rmw as some of the DIVCTLx require it
---
drivers/clk/renesas/rzv2h-cpg.c | 165 ++++++++++++++++++++++++++++++++
drivers/clk/renesas/rzv2h-cpg.h | 7 ++
2 files changed, 172 insertions(+)
diff --git a/drivers/clk/renesas/rzv2h-cpg.c b/drivers/clk/renesas/rzv2h-cpg.c
index 34221046dc46..54070dd1c019 100644
--- a/drivers/clk/renesas/rzv2h-cpg.c
+++ b/drivers/clk/renesas/rzv2h-cpg.c
@@ -45,14 +45,23 @@
#define PDIV(val) FIELD_GET(GENMASK(5, 0), (val))
#define SDIV(val) FIELD_GET(GENMASK(2, 0), (val))
+#define DDIV_DIVCTL_WEN(shift) (1 << ((shift) + 16))
+#define DDIV_GET_WIDTH(val) FIELD_GET(GENMASK(3, 0), (val))
+#define DDIV_GET_SHIFT(val) FIELD_GET(GENMASK(7, 4), (val))
+#define DDIV_GET_REG_OFFSET(val) FIELD_GET(GENMASK(18, 8), (val))
+#define DDIV_GET_MON(val) FIELD_GET(GENMASK(23, 19), (val))
+
#define GET_MOD_CLK_ID(base, index, bit) \
((base) + ((((index) * (16))) + (bit)))
+#define CPG_CLKSTATUS0 (0x700)
+
/**
* struct rzv2h_cpg_priv - Clock Pulse Generator Private Data
*
* @dev: CPG device
* @base: CPG register block base address
+ * @rmw_lock: protects register accesses
* @clks: Array containing all Core and Module Clocks
* @num_core_clks: Number of Core Clocks in clks[]
* @num_mod_clks: Number of Module Clocks in clks[]
@@ -64,6 +73,7 @@
struct rzv2h_cpg_priv {
struct device *dev;
void __iomem *base;
+ spinlock_t rmw_lock;
struct clk **clks;
unsigned int num_core_clks;
@@ -108,6 +118,21 @@ struct mod_clock {
#define to_mod_clock(_hw) container_of(_hw, struct mod_clock, hw)
+/**
+ * struct ddiv_clk - DDIV clock
+ *
+ * @priv: CPG private data
+ * @div: divider clk
+ * @mon: monitor bit in CPG_CLKSTATUS0 register
+ */
+struct ddiv_clk {
+ struct rzv2h_cpg_priv *priv;
+ struct clk_divider div;
+ u8 mon;
+};
+
+#define to_ddiv_clock(_div) container_of(_div, struct ddiv_clk, div)
+
static unsigned long rzv2h_cpg_pll_clk_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
@@ -173,6 +198,141 @@ rzv2h_cpg_pll_clk_register(const struct cpg_core_clk *core,
return pll_clk->hw.clk;
}
+static unsigned long rzv2h_ddiv_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct clk_divider *divider = to_clk_divider(hw);
+ unsigned int val;
+
+ val = readl(divider->reg) >> divider->shift;
+ val &= clk_div_mask(divider->width);
+
+ return divider_recalc_rate(hw, parent_rate, val, divider->table,
+ divider->flags, divider->width);
+}
+
+static long rzv2h_ddiv_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *prate)
+{
+ struct clk_divider *divider = to_clk_divider(hw);
+
+ return divider_round_rate(hw, rate, prate, divider->table,
+ divider->width, divider->flags);
+}
+
+static int rzv2h_ddiv_determine_rate(struct clk_hw *hw,
+ struct clk_rate_request *req)
+{
+ struct clk_divider *divider = to_clk_divider(hw);
+
+ return divider_determine_rate(hw, req, divider->table, divider->width,
+ divider->flags);
+}
+
+static inline int rzv2h_cpg_wait_ddiv_clk_update_done(void __iomem *base, u8 mon)
+{
+ u32 bitmask = BIT(mon);
+ u32 val;
+
+ return readl_poll_timeout_atomic(base + CPG_CLKSTATUS0, val, !(val & bitmask), 10, 200);
+}
+
+static int rzv2h_ddiv_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct clk_divider *divider = to_clk_divider(hw);
+ struct ddiv_clk *ddiv = to_ddiv_clock(divider);
+ struct rzv2h_cpg_priv *priv = ddiv->priv;
+ unsigned long flags = 0;
+ int value;
+ u32 val;
+ int ret;
+
+ value = divider_get_val(rate, parent_rate, divider->table,
+ divider->width, divider->flags);
+ if (value < 0)
+ return value;
+
+ spin_lock_irqsave(divider->lock, flags);
+
+ ret = rzv2h_cpg_wait_ddiv_clk_update_done(priv->base, ddiv->mon);
+ if (ret)
+ goto ddiv_timeout;
+
+ val = readl(divider->reg) | DDIV_DIVCTL_WEN(divider->shift);
+ val &= ~(clk_div_mask(divider->width) << divider->shift);
+ val |= (u32)value << divider->shift;
+ writel(val, divider->reg);
+
+ ret = rzv2h_cpg_wait_ddiv_clk_update_done(priv->base, ddiv->mon);
+ if (ret)
+ goto ddiv_timeout;
+
+ spin_unlock_irqrestore(divider->lock, flags);
+
+ return 0;
+
+ddiv_timeout:
+ spin_unlock_irqrestore(divider->lock, flags);
+ return ret;
+}
+
+static const struct clk_ops rzv2h_ddiv_clk_divider_ops = {
+ .recalc_rate = rzv2h_ddiv_recalc_rate,
+ .round_rate = rzv2h_ddiv_round_rate,
+ .determine_rate = rzv2h_ddiv_determine_rate,
+ .set_rate = rzv2h_ddiv_set_rate,
+};
+
+static struct clk * __init
+rzv2h_cpg_ddiv_clk_register(const struct cpg_core_clk *core,
+ struct rzv2h_cpg_priv *priv)
+{
+ u8 shift = DDIV_GET_SHIFT(core->conf);
+ struct clk_init_data init = {};
+ struct device *dev = priv->dev;
+ const struct clk *parent;
+ const char *parent_name;
+ struct clk_divider *div;
+ struct ddiv_clk *ddiv;
+ int ret;
+
+ parent = priv->clks[core->parent];
+ if (IS_ERR(parent))
+ return ERR_CAST(parent);
+
+ parent_name = __clk_get_name(parent);
+
+ if ((shift + DDIV_GET_WIDTH(core->conf)) > 16)
+ return ERR_PTR(-EINVAL);
+
+ ddiv = devm_kzalloc(priv->dev, sizeof(*ddiv), GFP_KERNEL);
+ if (!ddiv)
+ return ERR_PTR(-ENOMEM);
+
+ init.name = core->name;
+ init.ops = &rzv2h_ddiv_clk_divider_ops;
+ init.parent_names = &parent_name;
+ init.num_parents = 1;
+
+ ddiv->priv = priv;
+ ddiv->mon = DDIV_GET_MON(core->conf);
+ div = &ddiv->div;
+ div->reg = priv->base + DDIV_GET_REG_OFFSET(core->conf);
+ div->shift = shift;
+ div->width = DDIV_GET_WIDTH(core->conf);
+ div->flags = core->flag;
+ div->lock = &priv->rmw_lock;
+ div->hw.init = &init;
+ div->table = core->dtable;
+
+ ret = devm_clk_hw_register(dev, &div->hw);
+ if (ret)
+ return ERR_PTR(ret);
+
+ return div->hw.clk;
+}
+
static struct clk
*rzv2h_cpg_clk_src_twocell_get(struct of_phandle_args *clkspec,
void *data)
@@ -254,6 +414,9 @@ rzv2h_cpg_register_core_clk(const struct cpg_core_clk *core,
case CLK_TYPE_PLL:
clk = rzv2h_cpg_pll_clk_register(core, priv, &rzv2h_cpg_pll_ops);
break;
+ case CLK_TYPE_DDIV:
+ clk = rzv2h_cpg_ddiv_clk_register(core, priv);
+ break;
default:
goto fail;
}
@@ -612,6 +775,8 @@ static int __init rzv2h_cpg_probe(struct platform_device *pdev)
if (!priv)
return -ENOMEM;
+ spin_lock_init(&priv->rmw_lock);
+
priv->dev = dev;
priv->base = devm_platform_ioremap_resource(pdev, 0);
diff --git a/drivers/clk/renesas/rzv2h-cpg.h b/drivers/clk/renesas/rzv2h-cpg.h
index 6df59e041701..936af15b648a 100644
--- a/drivers/clk/renesas/rzv2h-cpg.h
+++ b/drivers/clk/renesas/rzv2h-cpg.h
@@ -24,6 +24,8 @@ struct cpg_core_clk {
unsigned int mult;
unsigned int type;
unsigned int conf;
+ const struct clk_div_table *dtable;
+ u32 flag;
};
enum clk_types {
@@ -31,6 +33,7 @@ enum clk_types {
CLK_TYPE_IN, /* External Clock Input */
CLK_TYPE_FF, /* Fixed Factor Clock */
CLK_TYPE_PLL,
+ CLK_TYPE_DDIV, /* Dynamic Switching Divider */
};
/* BIT(31) indicates if CLK1/2 are accessible or not */
@@ -49,6 +52,10 @@ enum clk_types {
DEF_TYPE(_name, _id, CLK_TYPE_IN)
#define DEF_FIXED(_name, _id, _parent, _mult, _div) \
DEF_BASE(_name, _id, CLK_TYPE_FF, _parent, .div = _div, .mult = _mult)
+#define DEF_DDIV(_name, _id, _parent, _conf, _dtable) \
+ DEF_TYPE(_name, _id, CLK_TYPE_DDIV, .conf = _conf, \
+ .parent = _parent, .dtable = _dtable, \
+ .flag = CLK_DIVIDER_HIWORD_MASK)
/**
* struct rzv2h_mod_clk - Module Clocks definitions
--
2.34.1
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