diff mbox

[2/6] clk: shmobile: sh73a0 common clock framework implementation

Message ID 1399386233-11928-3-git-send-email-ulrich.hecht+renesas@gmail.com (mailing list archive)
State Changes Requested
Headers show

Commit Message

Ulrich Hecht May 6, 2014, 2:23 p.m. UTC
Driver for the SH73A0's clocks that are too specific to be supported by a
generic driver.

Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com>
---
 drivers/clk/shmobile/clk-sh73a0.c | 202 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 202 insertions(+)
 create mode 100644 drivers/clk/shmobile/clk-sh73a0.c

Comments

Geert Uytterhoeven May 7, 2014, 9:01 a.m. UTC | #1
Hi Ulrich,

On Tue, May 6, 2014 at 4:23 PM, Ulrich Hecht <ulrich.hecht@gmail.com> wrote:
> +struct div4_clk {
> +       const char *name;
> +       const char *parent;

parent is unused (but see below).

> +       unsigned int reg;
> +       unsigned int shift;
> +       unsigned int mask;
> +       int flags;

mask and flags are unused.

> +};
> +
> +static struct div4_clk div4_clks[] = {
> +       { "zg", "pll0", CPG_FRQCRA, 16,  0xd7f, CLK_ENABLE_ON_INIT },
> +       { "m3", "pll1", CPG_FRQCRA, 12, 0x1dff, CLK_ENABLE_ON_INIT },
> +       { "b",  "pll1", CPG_FRQCRA,  8,  0xdff, CLK_ENABLE_ON_INIT },
> +       { "m1", "pll1", CPG_FRQCRA,  4, 0x1dff, 0 },
> +       { "m2", "pll1", CPG_FRQCRA,  0, 0x1dff, 0 },
> +       { "z",  "pll0", CPG_FRQCRB, 24,  0x97f, 0 },
> +       { "zx", "pll1", CPG_FRQCRB, 12,  0xdff, 0 },
> +       { "hp", "pll1", CPG_FRQCRB,  4,  0xdff, 0 },

parents of zg and z are pll0...

> +       { NULL, 0, 0, 0, 0 },
> +};

> +               struct div4_clk *c;
> +               for (c = div4_clks; c->name; c++) {
> +                       if (!strcmp(name, c->name)) {
> +                               if (!strcmp(name, "zg"))
> +                                       parent_name = "pll0";

... parent of zg is pll0...

> +                               else
> +                                       parent_name = "pll1";

... while parent of z is pll1?

According to clock-sh73a0.c and the AG5 docs, both have pll0 as parent.

But why not use "parent_name = c->parent;"?

> +                               table = div4_div_table;
> +                               reg = c->reg;
> +                               shift = c->shift;
> +                               break;
> +                       }

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds
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Ulrich Hecht May 12, 2014, 1:47 p.m. UTC | #2
On Wed, May 7, 2014 at 11:01 AM, Geert Uytterhoeven
<geert@linux-m68k.org> wrote:
> But why not use "parent_name = c->parent;"?

Uh... yes, very good point...

CU
Uli
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diff mbox

Patch

diff --git a/drivers/clk/shmobile/clk-sh73a0.c b/drivers/clk/shmobile/clk-sh73a0.c
new file mode 100644
index 0000000..95edc8d
--- /dev/null
+++ b/drivers/clk/shmobile/clk-sh73a0.c
@@ -0,0 +1,202 @@ 
+/*
+ * sh73a0 Core CPG Clocks
+ *
+ * Copyright (C) 2014  Ulrich Hecht
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/clkdev.h>
+#include <linux/clk/shmobile.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/spinlock.h>
+
+struct sh73a0_cpg {
+	struct clk_onecell_data data;
+	spinlock_t lock;
+	void __iomem *reg;
+};
+
+#define CPG_FRQCRA	0
+#define CPG_FRQCRB	4
+#define CPG_SD0CKCR	0x74
+#define CPG_SD1CKCR	0x78
+#define CPG_SD2CKCR	0x7c
+#define CPG_PLLECR	0xd0
+#define CPG_PLL0CR	0xd8
+#define CPG_PLL1CR	0x28
+#define CPG_PLL2CR	0x2c
+#define CPG_PLL3CR	0xdc
+#define CPG_CKSCR	0xc0
+#define CPG_DSI0PHYCR	0x6c
+#define CPG_DSI1PHYCR	0x70
+
+#define CLK_ENABLE_ON_INIT BIT(0)
+
+struct div4_clk {
+	const char *name;
+	const char *parent;
+	unsigned int reg;
+	unsigned int shift;
+	unsigned int mask;
+	int flags;
+};
+
+static struct div4_clk div4_clks[] = {
+	{ "zg", "pll0", CPG_FRQCRA, 16,  0xd7f, CLK_ENABLE_ON_INIT },
+	{ "m3", "pll1", CPG_FRQCRA, 12, 0x1dff, CLK_ENABLE_ON_INIT },
+	{ "b",  "pll1", CPG_FRQCRA,  8,  0xdff, CLK_ENABLE_ON_INIT },
+	{ "m1", "pll1", CPG_FRQCRA,  4, 0x1dff, 0 },
+	{ "m2", "pll1", CPG_FRQCRA,  0, 0x1dff, 0 },
+	{ "z",  "pll0", CPG_FRQCRB, 24,  0x97f, 0 },
+	{ "zx", "pll1", CPG_FRQCRB, 12,  0xdff, 0 },
+	{ "hp", "pll1", CPG_FRQCRB,  4,  0xdff, 0 },
+	{ NULL, 0, 0, 0, 0 },
+};
+
+static const struct clk_div_table div4_div_table[] = {
+	{ 0, 2 }, { 1, 3 }, { 2, 4 }, { 3, 6 }, { 4, 8 }, { 5, 12 },
+	{ 6, 16 }, { 7, 18 }, { 8, 24 }, { 10, 36 }, { 11, 48 },
+	{ 12, 7 }, { 0, 0 }
+};
+
+static struct clk * __init
+sh73a0_cpg_register_clock(struct device_node *np, struct sh73a0_cpg *cpg,
+			     const char *name)
+{
+	const struct clk_div_table *table = NULL;
+	const char *parent_name;
+	unsigned int shift, reg;
+	unsigned int mult = 1;
+	unsigned int div = 1;
+
+	if (!strcmp(name, "main")) {
+		/* extal1, extal1_div2, extal2, extal2_div2 */
+		parent_name = of_clk_get_parent_name(np,
+			(clk_readl(cpg->reg + CPG_CKSCR) >> 28) & 3);
+	} else if (!strncmp(name, "pll", 3)) {
+		void __iomem *enable_reg = cpg->reg;
+		u32 enable_bit = name[3] - '0';
+		parent_name = "main";
+		switch (enable_bit) {
+		case 0:
+			enable_reg += CPG_PLL0CR;
+			break;
+		case 1:
+			enable_reg += CPG_PLL1CR;
+			break;
+		case 2:
+			enable_reg += CPG_PLL2CR;
+			break;
+		case 3:
+			enable_reg += CPG_PLL3CR;
+			break;
+		default:
+			return ERR_PTR(-EINVAL);
+		}
+		if (clk_readl(cpg->reg + CPG_PLLECR) & BIT(enable_bit)) {
+			mult = ((clk_readl(enable_reg) >> 24) & 0x3f) + 1;
+			/* handle CFG bit for PLL1 and PLL2 */
+			if (enable_bit == 1 || enable_bit == 2)
+				if (clk_readl(enable_reg) & BIT(20))
+					mult *= 2;
+		}
+	} else if (!strcmp(name, "dsi0phy") || !strcmp(name, "dsi1phy")) {
+		u32 phy_no = name[3] - '0';
+		void __iomem *dsi_reg = cpg->reg +
+			(phy_no ? CPG_DSI1PHYCR : CPG_DSI0PHYCR);
+		parent_name = phy_no ? "dsi1pck" : "dsi0pck";
+		div = __raw_readl(dsi_reg);
+		if (!(div & 0xb8000))
+			div = 1;
+		else
+			div = (div & 0x3f) + 1;
+	} else {
+		struct div4_clk *c;
+		for (c = div4_clks; c->name; c++) {
+			if (!strcmp(name, c->name)) {
+				if (!strcmp(name, "zg"))
+					parent_name = "pll0";
+				else
+					parent_name = "pll1";
+				table = div4_div_table;
+				reg = c->reg;
+				shift = c->shift;
+				break;
+			}
+		}
+		if (!c->name)
+			return ERR_PTR(-EINVAL);
+	}
+
+	if (!table) {
+		return clk_register_fixed_factor(NULL, name, parent_name, 0,
+						 mult, div);
+	} else {
+		return clk_register_divider_table(NULL, name, parent_name, 0,
+						  cpg->reg + reg, shift, 4, 0,
+						  table, &cpg->lock);
+	}
+}
+
+static void __init sh73a0_cpg_clocks_init(struct device_node *np)
+{
+	struct sh73a0_cpg *cpg;
+	struct clk **clks;
+	unsigned int i;
+	int num_clks;
+
+	num_clks = of_property_count_strings(np, "clock-output-names");
+	if (num_clks < 0) {
+		pr_err("%s: failed to count clocks\n", __func__);
+		return;
+	}
+
+	cpg = kzalloc(sizeof(*cpg), GFP_KERNEL);
+	clks = kzalloc(num_clks * sizeof(*clks), GFP_KERNEL);
+	if (cpg == NULL || clks == NULL) {
+		/* We're leaking memory on purpose, there's no point in cleaning
+		 * up as the system won't boot anyway.
+		 */
+		return;
+	}
+
+	spin_lock_init(&cpg->lock);
+
+	cpg->data.clks = clks;
+	cpg->data.clk_num = num_clks;
+
+	cpg->reg = of_iomap(np, 0);
+	if (WARN_ON(cpg->reg == NULL))
+		return;
+
+	/* Set SDHI clocks to a known state */
+	clk_writel(0x108, cpg->reg + CPG_SD0CKCR);
+	clk_writel(0x108, cpg->reg + CPG_SD1CKCR);
+	clk_writel(0x108, cpg->reg + CPG_SD2CKCR);
+
+	for (i = 0; i < num_clks; ++i) {
+		const char *name;
+		struct clk *clk;
+
+		of_property_read_string_index(np, "clock-output-names", i,
+					      &name);
+
+		clk = sh73a0_cpg_register_clock(np, cpg, name);
+		if (IS_ERR(clk))
+			pr_err("%s: failed to register %s %s clock (%ld)\n",
+			       __func__, np->name, name, PTR_ERR(clk));
+		else
+			cpg->data.clks[i] = clk;
+	}
+
+	of_clk_add_provider(np, of_clk_src_onecell_get, &cpg->data);
+}
+CLK_OF_DECLARE(sh73a0_cpg_clks, "renesas,sh73a0-cpg-clocks",
+	       sh73a0_cpg_clocks_init);