[PATCH V2 1/4] clk: bcm2835: avoid the use of BCM2835_CLOCK_COUNT in clk-bcm2835

kernel at martin.sperl.org kernel at martin.sperl.org
Mon Jan 11 11:55:53 PST 2016


From: Martin Sperl <kernel at martin.sperl.org>

As the use of BCM2835_CLOCK_COUNT in
include/dt-bindings/clock/bcm2835.h is frowned upon as
it needs to get modified every time a new clock gets introduced
this patch changes the clk-bcm2835 driver to use a different
scheme for registration of clocks and pll, so that there
is no more need for BCM2835_CLOCK_COUNT to be defined.

The way the patch is designed also makes sure to allow control
the order in which the clocks are defined.

Signed-off-by: Martin Sperl <kernel at martin.sperl.org>
---
 drivers/clk/bcm/clk-bcm2835.c       |  208 +++++++++++++++++++++++++----------
 include/dt-bindings/clock/bcm2835.h |    2 -
 2 files changed, 147 insertions(+), 63 deletions(-)

diff --git a/drivers/clk/bcm/clk-bcm2835.c b/drivers/clk/bcm/clk-bcm2835.c
index 015e687..759202a 100644
--- a/drivers/clk/bcm/clk-bcm2835.c
+++ b/drivers/clk/bcm/clk-bcm2835.c
@@ -288,7 +288,7 @@ struct bcm2835_cprman {
 	const char *osc_name;

 	struct clk_onecell_data onecell;
-	struct clk *clks[BCM2835_CLOCK_COUNT];
+	struct clk *clks[];
 };

 static inline void cprman_write(struct bcm2835_cprman *cprman, u32 reg, u32 val)
@@ -1498,14 +1498,146 @@ static struct clk *bcm2835_register_clock(struct bcm2835_cprman *cprman,
 	return devm_clk_register(cprman->dev, &clock->hw);
 }

+enum bcm2835_clk_register {
+	bcm2835_clk_register_pll,
+	bcm2835_clk_register_pll_div,
+	bcm2835_clk_register_clock,
+};
+
+/*the list of clocks and plls to register */
+enum bcm2835_register_clock_type {
+	CLK_TYPE_UNSET,
+	CLK_TYPE_PLL,
+	CLK_TYPE_PLL_DIV,
+	CLK_TYPE_CLOCK,
+};
+
+struct bcm2835_register_clock {
+	size_t index;
+	enum bcm2835_register_clock_type clock_type;
+	const void *data;
+};
+
+#define _REGISTER(i, t, d) { .index = i, .clock_type = t, .data = d }
+
+#define REGISTER_PLL(i, d)	_REGISTER(i, CLK_TYPE_PLL, d)
+#define REGISTER_PLL_DIV(i, d)	_REGISTER(i, CLK_TYPE_PLL_DIV, d)
+#define REGISTER_CLOCK(i, d)	_REGISTER(i, CLK_TYPE_CLOCK, d)
+
+/*
+ * note that this array is processed first to last,
+ * so that we can define inititalization order.
+ * with the order right now: pll, pll_div and then clock
+ * this allows to retain the existing id- mapping in the device tree.
+ * ths also means we have to have some more explicit coding
+ * and can not use sparse arrays or similar.
+ */
+static const struct bcm2835_register_clock bcm2835_register_clocks[] = {
+	/* the PLL clocks */
+	REGISTER_PLL(BCM2835_PLLA, &bcm2835_plla_data),
+	REGISTER_PLL(BCM2835_PLLB, &bcm2835_pllb_data),
+	REGISTER_PLL(BCM2835_PLLC, &bcm2835_pllc_data),
+	REGISTER_PLL(BCM2835_PLLD, &bcm2835_plld_data),
+	REGISTER_PLL(BCM2835_PLLH, &bcm2835_pllh_data),
+	/* the PLL dividers */
+	REGISTER_PLL_DIV(BCM2835_PLLA_CORE, &bcm2835_plla_core_data),
+	REGISTER_PLL_DIV(BCM2835_PLLA_PER, &bcm2835_plla_per_data),
+	REGISTER_PLL_DIV(BCM2835_PLLC_CORE0, &bcm2835_pllc_core0_data),
+	REGISTER_PLL_DIV(BCM2835_PLLC_CORE1, &bcm2835_pllc_core1_data),
+	REGISTER_PLL_DIV(BCM2835_PLLC_CORE2, &bcm2835_pllc_core2_data),
+	REGISTER_PLL_DIV(BCM2835_PLLC_PER, &bcm2835_pllc_per_data),
+	REGISTER_PLL_DIV(BCM2835_PLLD_CORE, &bcm2835_plld_core_data),
+	REGISTER_PLL_DIV(BCM2835_PLLD_PER, &bcm2835_plld_per_data),
+	REGISTER_PLL_DIV(BCM2835_PLLH_RCAL, &bcm2835_pllh_rcal_data),
+	REGISTER_PLL_DIV(BCM2835_PLLH_AUX, &bcm2835_pllh_aux_data),
+	REGISTER_PLL_DIV(BCM2835_PLLH_PIX, &bcm2835_pllh_pix_data),
+	/* the clocks */
+	REGISTER_CLOCK(BCM2835_CLOCK_TIMER, &bcm2835_clock_timer_data),
+	REGISTER_CLOCK(BCM2835_CLOCK_OTP, &bcm2835_clock_otp_data),
+	REGISTER_CLOCK(BCM2835_CLOCK_TSENS, &bcm2835_clock_tsens_data),
+	REGISTER_CLOCK(BCM2835_CLOCK_VPU, &bcm2835_clock_vpu_data),
+	REGISTER_CLOCK(BCM2835_CLOCK_V3D, &bcm2835_clock_v3d_data),
+	REGISTER_CLOCK(BCM2835_CLOCK_ISP, &bcm2835_clock_isp_data),
+	REGISTER_CLOCK(BCM2835_CLOCK_H264, &bcm2835_clock_h264_data),
+	REGISTER_CLOCK(BCM2835_CLOCK_V3D, &bcm2835_clock_v3d_data),
+	REGISTER_CLOCK(BCM2835_CLOCK_SDRAM, &bcm2835_clock_sdram_data),
+	REGISTER_CLOCK(BCM2835_CLOCK_UART, &bcm2835_clock_uart_data),
+	REGISTER_CLOCK(BCM2835_CLOCK_VEC, &bcm2835_clock_vec_data),
+	REGISTER_CLOCK(BCM2835_CLOCK_HSM, &bcm2835_clock_hsm_data),
+	REGISTER_CLOCK(BCM2835_CLOCK_EMMC, &bcm2835_clock_emmc_data),
+	REGISTER_CLOCK(BCM2835_CLOCK_PWM, &bcm2835_clock_pwm_data),
+};
+
+void bcm2835_register_duplicate_index(
+	struct device *dev, const struct bcm2835_register_clock *reg,
+	struct clk *clk)
+{
+	const char *name, *type;
+
+	switch (reg->clock_type) {
+	case CLK_TYPE_PLL:
+		name = ((struct bcm2835_pll_data *)reg->data)->name;
+		type = "pll";
+		break;
+	case CLK_TYPE_PLL_DIV:
+		name = ((struct bcm2835_pll_divider_data *)reg->data)->name;
+		type = "pll divider";
+		break;
+	case CLK_TYPE_CLOCK:
+		name = ((struct bcm2835_clock_data *)reg->data)->name;
+		type = "clock";
+		break;
+	default:
+		dev_err(dev, "Unsupported clock type %d for index %d\n",
+			reg->clock_type, reg->index);
+		return;
+	}
+
+	dev_err(dev,
+		"Could not register %s \"%s\" because index %i already defined as clock: %pC\n",
+		type, name, reg->index, clk);
+}
+
+struct clk *bcm2835_register_pllclock(
+	struct device *dev, struct bcm2835_cprman *cprman,
+	const struct bcm2835_register_clock *reg)
+{
+	switch (reg->clock_type) {
+	case CLK_TYPE_PLL:
+		return bcm2835_register_pll(
+			cprman, reg->data);
+	case CLK_TYPE_PLL_DIV:
+		return bcm2835_register_pll_divider(
+			cprman, reg->data);
+	case CLK_TYPE_CLOCK:
+		return bcm2835_register_clock(
+			cprman, reg->data);
+	default:
+		dev_err(dev, "Unsupported clock type %d for index %d\n",
+			reg->clock_type, reg->index);
+	}
+
+	return NULL;
+}
+
 static int bcm2835_clk_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct clk **clks;
+	size_t clk_cnt;
 	struct bcm2835_cprman *cprman;
 	struct resource *res;
+	size_t i;
+
+	/* find the max clock index */
+	clk_cnt = BCM2835_CLOCK_PERI_IMAGE; /* see below */
+	for (i = 0; i < ARRAY_SIZE(bcm2835_register_clocks); i++)
+		clk_cnt = max(clk_cnt, bcm2835_register_clocks[i].index);
+	clk_cnt += 1;

-	cprman = devm_kzalloc(dev, sizeof(*cprman), GFP_KERNEL);
+	cprman = devm_kzalloc(dev,
+			      sizeof(*cprman) + clk_cnt * sizeof(*clks),
+			      GFP_KERNEL);
 	if (!cprman)
 		return -ENOMEM;

@@ -1522,65 +1654,22 @@ static int bcm2835_clk_probe(struct platform_device *pdev)

 	platform_set_drvdata(pdev, cprman);

-	cprman->onecell.clk_num = BCM2835_CLOCK_COUNT;
+	cprman->onecell.clk_num = clk_cnt;
 	cprman->onecell.clks = cprman->clks;
 	clks = cprman->clks;

-	clks[BCM2835_PLLA] = bcm2835_register_pll(cprman, &bcm2835_plla_data);
-	clks[BCM2835_PLLB] = bcm2835_register_pll(cprman, &bcm2835_pllb_data);
-	clks[BCM2835_PLLC] = bcm2835_register_pll(cprman, &bcm2835_pllc_data);
-	clks[BCM2835_PLLD] = bcm2835_register_pll(cprman, &bcm2835_plld_data);
-	clks[BCM2835_PLLH] = bcm2835_register_pll(cprman, &bcm2835_pllh_data);
-
-	clks[BCM2835_PLLA_CORE] =
-		bcm2835_register_pll_divider(cprman, &bcm2835_plla_core_data);
-	clks[BCM2835_PLLA_PER] =
-		bcm2835_register_pll_divider(cprman, &bcm2835_plla_per_data);
-	clks[BCM2835_PLLC_CORE0] =
-		bcm2835_register_pll_divider(cprman, &bcm2835_pllc_core0_data);
-	clks[BCM2835_PLLC_CORE1] =
-		bcm2835_register_pll_divider(cprman, &bcm2835_pllc_core1_data);
-	clks[BCM2835_PLLC_CORE2] =
-		bcm2835_register_pll_divider(cprman, &bcm2835_pllc_core2_data);
-	clks[BCM2835_PLLC_PER] =
-		bcm2835_register_pll_divider(cprman, &bcm2835_pllc_per_data);
-	clks[BCM2835_PLLD_CORE] =
-		bcm2835_register_pll_divider(cprman, &bcm2835_plld_core_data);
-	clks[BCM2835_PLLD_PER] =
-		bcm2835_register_pll_divider(cprman, &bcm2835_plld_per_data);
-	clks[BCM2835_PLLH_RCAL] =
-		bcm2835_register_pll_divider(cprman, &bcm2835_pllh_rcal_data);
-	clks[BCM2835_PLLH_AUX] =
-		bcm2835_register_pll_divider(cprman, &bcm2835_pllh_aux_data);
-	clks[BCM2835_PLLH_PIX] =
-		bcm2835_register_pll_divider(cprman, &bcm2835_pllh_pix_data);
-
-	clks[BCM2835_CLOCK_TIMER] =
-		bcm2835_register_clock(cprman, &bcm2835_clock_timer_data);
-	clks[BCM2835_CLOCK_OTP] =
-		bcm2835_register_clock(cprman, &bcm2835_clock_otp_data);
-	clks[BCM2835_CLOCK_TSENS] =
-		bcm2835_register_clock(cprman, &bcm2835_clock_tsens_data);
-	clks[BCM2835_CLOCK_VPU] =
-		bcm2835_register_clock(cprman, &bcm2835_clock_vpu_data);
-	clks[BCM2835_CLOCK_V3D] =
-		bcm2835_register_clock(cprman, &bcm2835_clock_v3d_data);
-	clks[BCM2835_CLOCK_ISP] =
-		bcm2835_register_clock(cprman, &bcm2835_clock_isp_data);
-	clks[BCM2835_CLOCK_H264] =
-		bcm2835_register_clock(cprman, &bcm2835_clock_h264_data);
-	clks[BCM2835_CLOCK_V3D] =
-		bcm2835_register_clock(cprman, &bcm2835_clock_v3d_data);
-	clks[BCM2835_CLOCK_SDRAM] =
-		bcm2835_register_clock(cprman, &bcm2835_clock_sdram_data);
-	clks[BCM2835_CLOCK_UART] =
-		bcm2835_register_clock(cprman, &bcm2835_clock_uart_data);
-	clks[BCM2835_CLOCK_VEC] =
-		bcm2835_register_clock(cprman, &bcm2835_clock_vec_data);
-	clks[BCM2835_CLOCK_HSM] =
-		bcm2835_register_clock(cprman, &bcm2835_clock_hsm_data);
-	clks[BCM2835_CLOCK_EMMC] =
-		bcm2835_register_clock(cprman, &bcm2835_clock_emmc_data);
+	/* now register */
+	for (i = 0; i < ARRAY_SIZE(bcm2835_register_clocks); i++) {
+		if (clks[bcm2835_register_clocks[i].index])
+			bcm2835_register_duplicate_index(
+				dev, &bcm2835_register_clocks[i],
+				clks[bcm2835_register_clocks[i].index]);
+		else
+			clks[bcm2835_register_clocks[i].index] =
+				bcm2835_register_pllclock(
+					dev, cprman,
+					&bcm2835_register_clocks[i]);
+	}

 	/*
 	 * CM_PERIICTL (and CM_PERIACTL, CM_SYSCTL and CM_VPUCTL if
@@ -1594,9 +1683,6 @@ static int bcm2835_clk_probe(struct platform_device *pdev)
 				  cprman->regs + CM_PERIICTL, CM_GATE_BIT,
 				  0, &cprman->regs_lock);

-	clks[BCM2835_CLOCK_PWM] =
-		bcm2835_register_clock(cprman, &bcm2835_clock_pwm_data);
-
 	return of_clk_add_provider(dev->of_node, of_clk_src_onecell_get,
 				   &cprman->onecell);
 }
diff --git a/include/dt-bindings/clock/bcm2835.h b/include/dt-bindings/clock/bcm2835.h
index 61f1d20..87235ac 100644
--- a/include/dt-bindings/clock/bcm2835.h
+++ b/include/dt-bindings/clock/bcm2835.h
@@ -44,5 +44,3 @@
 #define BCM2835_CLOCK_EMMC		28
 #define BCM2835_CLOCK_PERI_IMAGE	29
 #define BCM2835_CLOCK_PWM		30
-
-#define BCM2835_CLOCK_COUNT		31
--
1.7.10.4




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