Re: [PATCH v2] Add TI CDCE925 I2C controlled clock synthesizer driver

From: Mike Looijmans
Date: Fri Apr 10 2015 - 04:02:44 EST

ïHello,

Sorry to bother you again, but I haven't seen any feedback on this, could you please inform whether the patch is okay or needs rework?

Kind regards,
Mike.

On 12-01-15 04:04, Mike Turquette wrote:
On Thu, Jan 8, 2015 at 11:01 PM, Mike Looijmans <mike.looijmans@xxxxxxxx> wrote:
Just a ping to inform if you've had had time to look at this?

Its in the queue for review this week. A lot to catch up on after the
holidays. Thanks for the ping.

Regards,
Mike


Mike.

On 12/04/2014 08:26 AM, Mike Looijmans wrote:

This driver supports the TI CDCE925 programmable clock synthesizer.
The chip contains two PLLs with spread-spectrum clocking support and
five output dividers. The driver only supports the following setup,
and uses a fixed setting for the output muxes:
Y1 is derived from the input clock
Y2 and Y3 derive from PLL1
Y4 and Y5 derive from PLL2
Given a target output frequency, the driver will set the PLL and
divider to best approximate the desired output.

Signed-off-by: Mike Looijmans <mike.looijmans@xxxxxxxx>
---

v2: Coding style check
Add devicetree binding documentation

.../devicetree/bindings/clock/cdce925.txt | 61 ++
drivers/clk/Kconfig | 17 +
drivers/clk/Makefile | 1 +
drivers/clk/clk-cdce925.c | 792
++++++++++++++++++++
4 files changed, 871 insertions(+)
create mode 100644 Documentation/devicetree/bindings/clock/cdce925.txt
create mode 100644 drivers/clk/clk-cdce925.c

diff --git a/Documentation/devicetree/bindings/clock/cdce925.txt
b/Documentation/devicetree/bindings/clock/cdce925.txt
new file mode 100644
index 0000000..0eac770
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/cdce925.txt
@@ -0,0 +1,61 @@
+Binding for TO CDCE925 programmable I2C clock synthesizers.
+
+Reference
+This binding uses the common clock binding[1].
+
+[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
+[2] http://www.ti.com/product/cdce925
+
+Required properties:
+ - compatible: Shall be one of "cdce925", "cdce925pw",
+ - reg: I2C device address.
+ - clocks: Points to a fixed parent clock that provides the input
frequency.
+ - #clock-cells: From common clock bindings: Shall be 1.
+
+Optional properties:
+ - xtal-load-pf: Crystal load-capacitor value to fine-tune performance on
a
+ board, or to compensate for external influences.
+
+
+For each connected output Y1 through Y5, a child node should be provided.
Each
+child node must have the following properties:
+ - #clock-cells: From common clock bindings: Shall be 0.
+Optional properties for the output nodes:
+ - clock-frequency: Output frequency to generate. This defines the output
+ frequency set during boot. It can be reprogrammed
during
+ runtime through the common clock framework.
+
+For both PLL1 and PLL2 an optional child node can be used to specify
spread
+spectrum clocking parameters.
+ - spread-spectrum: SSC mode as defined in the data sheet.
+ - spread-spectrum-center: Use "centered" mode instead of "max" mode.
When this
+ is present, the clock runs at the requested frequency on average.
+
+
+Example:
+
+ clockgen: cdce925pw@64 {
+ compatible = "cdce925";
+ reg = <0x64>;
+ clocks = <&xtal_27Mhz>;
+ xtal-load-pf = <5>;
+ #clock-cells = <1>;
+ /* PLL options to get SSC 1% centered */
+ PLL2 {
+ spread-spectrum = <4>;
+ spread-spectrum-center;
+ };
+ /* Outputs calculate mux and divider settings */
+ Y1 {
+ #clock-cells = <0>;
+ clock-frequency = <27000>;
+ };
+ audio_clock: Y2 {
+ #clock-cells = <0>;
+ clock-frequency = <12288000>; /* SPDIF audio */
+ };
+ hdmi_pixel_clock: Y4 {
+ #clock-cells = <0>;
+ clock-frequency = <148500000>; /* HD-video */
+ };
+ };
diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
index 455fd17..4e474b3 100644
--- a/drivers/clk/Kconfig
+++ b/drivers/clk/Kconfig
@@ -77,6 +77,23 @@ config COMMON_CLK_SI570
This driver supports Silicon Labs 570/571/598/599 programmable
clock generators.

+config COMMON_CLK_CDCE925
+ tristate "Clock driver for TI CDCE925 devices"
+ depends on I2C
+ depends on OF
+ select REGMAP_I2C
+ help
+ ---help---
+ This driver supports the TI CDCE925 programmable clock
synthesizer.
+ The chip contains two PLLs with spread-spectrum clocking support
and
+ five output dividers. The driver only supports the following
setup,
+ and uses a fixed setting for the output muxes.
+ Y1 is derived from the input clock
+ Y2 and Y3 derive from PLL1
+ Y4 and Y5 derive from PLL2
+ Given a target output frequency, the driver will set the PLL and
+ divider to best approximate the desired output.
+
config COMMON_CLK_S2MPS11
tristate "Clock driver for S2MPS1X/S5M8767 MFD"
depends on MFD_SEC_CORE
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index d5fba5b..c476066 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -35,6 +35,7 @@ obj-$(CONFIG_COMMON_CLK_RK808) +=
clk-rk808.o
obj-$(CONFIG_COMMON_CLK_S2MPS11) += clk-s2mps11.o
obj-$(CONFIG_COMMON_CLK_SI5351) += clk-si5351.o
obj-$(CONFIG_COMMON_CLK_SI570) += clk-si570.o
+obj-$(CONFIG_COMMON_CLK_CDCE925) += clk-cdce925.o
obj-$(CONFIG_CLK_TWL6040) += clk-twl6040.o
obj-$(CONFIG_ARCH_U300) += clk-u300.o
obj-$(CONFIG_ARCH_VT8500) += clk-vt8500.o
diff --git a/drivers/clk/clk-cdce925.c b/drivers/clk/clk-cdce925.c
new file mode 100644
index 0000000..faa867f
--- /dev/null
+++ b/drivers/clk/clk-cdce925.c
@@ -0,0 +1,792 @@
+/*
+ * Driver for TI Dual PLL CDCE925 clock synthesizer
+ *
+ * This driver always connects the Y1 to the input clock, Y2/Y3 to PLL1
+ * and Y4/Y5 to PLL2. PLL frequency is set on a first-come-first-serve
+ * basis. Clients can directly request any frequency that the chip can
+ * deliver using the standard clk framework. In addition, the device can
+ * be configured and activated via the devicetree.
+ *
+ * Copyright (C) 2014, Topic Embedded Products
+ * Licenced under GPL
+ */
+#include <linux/clk-provider.h>
+#include <linux/clk-private.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/gcd.h>
+
+/* The chip has 2 PLLs which can be routed through dividers to 5 outputs.
+ * Model this as 2 PLL clocks which are parents to the outputs.
+ */
+#define NUMBER_OF_PLLS 2
+#define NUMBER_OF_OUTPUTS 5
+
+#define CDCE925_REG_GLOBAL1 0x01
+#define CDCE925_REG_Y1SPIPDIVH 0x02
+#define CDCE925_REG_PDIVL 0x03
+#define CDCE925_REG_XCSEL 0x05
+/* PLL parameters start at 0x10, steps of 0x10 */
+#define CDCE925_OFFSET_PLL 0x10
+/* Add CDCE925_OFFSET_PLL * (pll) to these registers before sending */
+#define CDCE925_PLL_MUX_OUTPUTS 0x14
+#define CDCE925_PLL_MULDIV 0x18
+
+#define CDCE925_PLL_FREQUENCY_MIN 80000000
+#define CDCE925_PLL_FREQUENCY_MAX 230000000
+struct clk_cdce925_chip;
+
+struct clk_cdce925_output {
+ struct clk_hw hw;
+ struct clk_cdce925_chip *chip;
+ u8 index;
+ u16 pdiv; /* 1..127 for Y2-Y5; 1..1023 for Y1 */
+};
+#define to_clk_cdce925_output(_hw) \
+ container_of(_hw, struct clk_cdce925_output, hw)
+
+struct clk_cdce925_pll {
+ struct clk_hw hw;
+ struct clk_cdce925_chip *chip;
+ u8 index;
+ u16 m; /* 1..511 */
+ u16 n; /* 1..4095 */
+};
+#define to_clk_cdce925_pll(_hw) container_of(_hw, struct
clk_cdce925_pll, hw)
+
+struct clk_cdce925_chip {
+ struct regmap *regmap;
+ struct i2c_client *i2c_client;
+ struct clk_cdce925_pll pll[NUMBER_OF_PLLS];
+ struct clk_cdce925_output clk[NUMBER_OF_OUTPUTS];
+};
+
+/* ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** */
+
+static unsigned long cdce925_pll_calculate_rate(unsigned long
parent_rate,
+ u16 n, u16 m)
+{
+ if ((!m || !n) || (m == n))
+ return parent_rate; /* In bypass mode runs at same
frequency */
+ return mult_frac(parent_rate, (unsigned long)n, (unsigned long)m);
+}
+
+static unsigned long cdce925_pll_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ /* Output frequency of PLL is Fout = (Fin/Pdiv)*(N/M) */
+ struct clk_cdce925_pll *data = to_clk_cdce925_pll(hw);
+
+ return cdce925_pll_calculate_rate(parent_rate, data->n, data->m);
+}
+
+static int cdce925_pll_find_rate(unsigned long rate,
+ unsigned long parent_rate, u16 *n, u16 *m)
+{
+ if (rate <= parent_rate) {
+ /* Can always deliver parent_rate in bypass mode */
+ rate = parent_rate;
+ *n = 0;
+ *m = 0;
+ } else {
+ /* In PLL mode, need to apply min/max range */
+ unsigned long un;
+ unsigned long um;
+ unsigned long g;
+
+ if (rate < CDCE925_PLL_FREQUENCY_MIN)
+ rate = CDCE925_PLL_FREQUENCY_MIN;
+ else if (rate > CDCE925_PLL_FREQUENCY_MAX)
+ rate = CDCE925_PLL_FREQUENCY_MAX;
+
+ g = gcd(rate, parent_rate);
+ um = parent_rate / g;
+ un = rate / g;
+ /* When outside hw range, reduce to fit (rounding errors)
*/
+ while ((un > 4095) || (um > 511)) {
+ un >>= 1;
+ um >>= 1;
+ }
+ if (un == 0)
+ un = 1;
+ if (um == 0)
+ um = 1;
+
+ *n = un;
+ *m = um;
+ }
+
+ pr_debug("%s(%lu,%lu) n=%u m=%u\n",
+ __func__, rate, parent_rate, *n, *m);
+
+ return 0;
+}
+
+static long cdce925_pll_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *parent_rate)
+{
+ struct clk_cdce925_pll *data = to_clk_cdce925_pll(hw);
+ u16 n, m;
+ int ret;
+
+ pr_debug("%s (index=%d parent_rate=%lu rate=%lu)\n", __func__,
+ data->index, *parent_rate, rate);
+ ret = cdce925_pll_find_rate(rate, *parent_rate, &n, &m);
+ return (long)cdce925_pll_calculate_rate(*parent_rate, n, m);
+}
+
+static int cdce925_pll_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct clk_cdce925_pll *data = to_clk_cdce925_pll(hw);
+
+ if (!rate || (rate == parent_rate)) {
+ data->m = 0; /* Bypass mode */
+ data->n = 0;
+ return 0;
+ }
+
+ if ((rate < CDCE925_PLL_FREQUENCY_MIN) ||
+ (rate > CDCE925_PLL_FREQUENCY_MAX)) {
+ pr_debug("%s: rate %lu outside PLL range.\n", __func__,
rate);
+ return -EINVAL;
+ }
+
+ if (rate < parent_rate) {
+ pr_debug("%s: rate %lu less than parent rate %lu.\n",
__func__,
+ rate, parent_rate);
+ return -EINVAL;
+ }
+
+ return cdce925_pll_find_rate(rate, parent_rate, &data->n,
&data->m);
+}
+
+
+/* calculate p = max(0, 4 - int(log2 (n/m))) */
+static u8 cdce925_pll_calc_p(u16 n, u16 m)
+{
+ u8 p;
+ u16 r = n / m;
+
+ if (r >= 16)
+ return 0;
+ p = 4;
+ while (r > 1) {
+ r >>= 1;
+ --p;
+ }
+ return p;
+}
+
+/* Returns VCO range bits for VCO1_0_RANGE */
+static u8 cdce925_pll_calc_range_bits(struct clk_hw *hw, u16 n, u16 m)
+{
+ struct clk *parent = clk_get_parent(hw->clk);
+ unsigned long rate = clk_get_rate(parent);
+
+ rate = mult_frac(rate, (unsigned long)n, (unsigned long)m);
+ if (rate >= 175000000)
+ return 0x3;
+ if (rate >= 150000000)
+ return 0x02;
+ if (rate >= 125000000)
+ return 0x01;
+ return 0x00;
+}
+
+/* I2C clock, hence everything must happen in (un)prepare because this
+ * may sleep */
+static int cdce925_pll_prepare(struct clk_hw *hw)
+{
+ struct clk_cdce925_pll *data = to_clk_cdce925_pll(hw);
+ u16 n = data->n;
+ u16 m = data->m;
+ u16 r;
+ u8 q;
+ u8 p;
+ u16 nn;
+ u8 pll[4]; /* Bits are spread out over 4 byte registers */
+ u8 reg_ofs = data->index * CDCE925_OFFSET_PLL;
+ unsigned i;
+
+ pr_debug("%s: index=%d\n", __func__, data->index);
+
+ if ((!m || !n) || (m == n)) {
+ /* Set PLL mux to bypass mode, leave the rest as is */
+ regmap_update_bits(data->chip->regmap,
+ reg_ofs + CDCE925_PLL_MUX_OUTPUTS, 0x80, 0x80);
+ } else {
+ /* According to data sheet: */
+ /* p = max(0, 4 - int(log2 (n/m))) */
+ p = cdce925_pll_calc_p(n, m);
+ /* nn = n * 2^p */
+ nn = n * BIT(p);
+ /* q = int(nn/m) */
+ q = nn / m;
+ if ((q < 16) || (1 > 64)) {
+ pr_debug("%s invalid q=%d\n", __func__, q);
+ return -EINVAL;
+ }
+ r = nn - (m*q);
+ if (r > 511) {
+ pr_debug("%s invalid r=%d\n", __func__, r);
+ return -EINVAL;
+ }
+ pr_debug("%s n=%d m=%d p=%d q=%d r=%d\n", __func__,
+ n, m, p, q, r);
+ /* encode into register bits */
+ pll[0] = n >> 4;
+ pll[1] = ((n & 0x0F) << 4) | ((r >> 5) & 0x0F);
+ pll[2] = ((r & 0x1F) << 3) | ((q >> 3) & 0x07);
+ pll[3] = ((q & 0x07) << 5) | (p << 2) |
+ cdce925_pll_calc_range_bits(hw, n, m);
+ /* Write to registers */
+ for (i = 0; i < ARRAY_SIZE(pll); ++i)
+ regmap_write(data->chip->regmap,
+ reg_ofs + CDCE925_PLL_MULDIV + i, pll[i]);
+ /* Enable PLL */
+ regmap_update_bits(data->chip->regmap,
+ reg_ofs + CDCE925_PLL_MUX_OUTPUTS, 0x80, 0x00);
+ }
+
+ return 0;
+}
+
+static void cdce925_pll_unprepare(struct clk_hw *hw)
+{
+ struct clk_cdce925_pll *data = to_clk_cdce925_pll(hw);
+ u8 reg_ofs = data->index * CDCE925_OFFSET_PLL;
+
+ pr_debug("%s: index=%d\n", __func__, data->index);
+ regmap_update_bits(data->chip->regmap,
+ reg_ofs + CDCE925_PLL_MUX_OUTPUTS, 0x80, 0x80);
+}
+
+static const struct clk_ops cdce925_pll_ops = {
+ .prepare = cdce925_pll_prepare,
+ .unprepare = cdce925_pll_unprepare,
+ .recalc_rate = cdce925_pll_recalc_rate,
+ .round_rate = cdce925_pll_round_rate,
+ .set_rate = cdce925_pll_set_rate,
+};
+
+
+static void cdce925_clk_set_pdiv(struct clk_cdce925_output *data, u16
pdiv)
+{
+ pr_debug("%s: index=%d pdiv=%d\n", __func__, data->index, pdiv);
+ switch (data->index) {
+ case 0:
+ regmap_update_bits(data->chip->regmap,
+ CDCE925_REG_Y1SPIPDIVH,
+ 0x03, (pdiv >> 8) & 0x03);
+ regmap_write(data->chip->regmap, 0x03, pdiv & 0xFF);
+ break;
+ case 1:
+ regmap_update_bits(data->chip->regmap, 0x16, 0x7F, pdiv);
+ break;
+ case 2:
+ regmap_update_bits(data->chip->regmap, 0x17, 0x7F, pdiv);
+ break;
+ case 3:
+ regmap_update_bits(data->chip->regmap, 0x26, 0x7F, pdiv);
+ break;
+ case 4:
+ regmap_update_bits(data->chip->regmap, 0x27, 0x7F, pdiv);
+ break;
+ }
+}
+
+static void cdce925_clk_activate(struct clk_cdce925_output *data)
+{
+ pr_debug("%s: index=%d\n", __func__, data->index);
+ switch (data->index) {
+ case 0:
+ regmap_update_bits(data->chip->regmap,
+ CDCE925_REG_Y1SPIPDIVH, 0x0c, 0x0c);
+ break;
+ case 1:
+ case 2:
+ regmap_update_bits(data->chip->regmap, 0x14, 0x03, 0x03);
+ break;
+ case 3:
+ case 4:
+ regmap_update_bits(data->chip->regmap, 0x24, 0x03, 0x03);
+ break;
+ }
+}
+
+static int cdce925_clk_prepare(struct clk_hw *hw)
+{
+ struct clk_cdce925_output *data = to_clk_cdce925_output(hw);
+
+ pr_debug("%s: index=%d\n", __func__, data->index);
+ cdce925_clk_set_pdiv(data, data->pdiv);
+ cdce925_clk_activate(data);
+ return 0;
+}
+
+static void cdce925_clk_unprepare(struct clk_hw *hw)
+{
+ struct clk_cdce925_output *data = to_clk_cdce925_output(hw);
+
+ pr_debug("%s: index=%d\n", __func__, data->index);
+ /* Disable clock by setting divider to "0" */
+ cdce925_clk_set_pdiv(data, 0);
+}
+
+static unsigned long cdce925_clk_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct clk_cdce925_output *data = to_clk_cdce925_output(hw);
+
+ pr_debug("%s: index=%d parent_rate=%lu pdiv=%d\n", __func__,
+ data->index, parent_rate, data->pdiv);
+ if (data->pdiv)
+ return parent_rate / data->pdiv;
+ return 0;
+}
+
+static u16 cdce925_calc_divider(unsigned long rate,
+ unsigned long parent_rate)
+{
+ if (rate >= parent_rate) {
+ return 1;
+ } else if (rate) {
+ unsigned long divider = DIV_ROUND_CLOSEST(parent_rate,
rate);
+
+ if (divider > 0x7F) /* TODO: Y1 has 10-bit divider */
+ divider = 0x7F;
+ return (u16)divider;
+ } else {
+ return 0;
+ }
+}
+
+static unsigned long cdce925_clk_best_parent_rate(
+ struct clk_hw *hw, unsigned long rate)
+{
+ struct clk *pll = clk_get_parent(hw->clk);
+ struct clk *root = clk_get_parent(pll);
+ unsigned long root_rate = clk_get_rate(root);
+ unsigned long best_rate_error = rate;
+ u16 pdiv_min;
+ u16 pdiv_max;
+ u16 pdiv_best;
+ u16 pdiv_now;
+
+ if (root_rate % rate == 0)
+ return root_rate; /* Don't need the PLL, use bypass */
+
+ pdiv_min = (u16)max(1u, DIV_ROUND_UP(CDCE925_PLL_FREQUENCY_MIN,
rate));
+ pdiv_max = (u16)min(127u, CDCE925_PLL_FREQUENCY_MAX / rate);
+
+ if (pdiv_min > pdiv_max)
+ return 0; /* No can do? */
+
+ pdiv_best = pdiv_min;
+ for (pdiv_now = pdiv_min; pdiv_now < pdiv_max; ++pdiv_now) {
+ unsigned long target_rate = rate * pdiv_now;
+ long pll_rate = clk_round_rate(pll, target_rate);
+ unsigned long actual_rate;
+ unsigned long rate_error;
+
+ if (pll_rate <= 0)
+ continue;
+ actual_rate = pll_rate / pdiv_now;
+ rate_error = abs((long)actual_rate - (long)rate);
+ if (rate_error < best_rate_error) {
+ pdiv_best = pdiv_now;
+ best_rate_error = rate_error;
+ }
+ /* TODO: Consider PLL frequency based on smaller n/m
values
+ * and pick the better one if the error is equal */
+ }
+
+ return rate * pdiv_best;
+}
+
+static long cdce925_clk_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *parent_rate)
+{
+ struct clk_cdce925_output *data = to_clk_cdce925_output(hw);
+ unsigned long l_parent_rate = *parent_rate;
+ u16 divider = cdce925_calc_divider(rate, l_parent_rate);
+
+ pr_debug("%s (index=%d parent_rate=%lu rate=%lu)\n", __func__,
+ data->index, l_parent_rate, rate);
+ if (l_parent_rate / divider != rate) {
+ l_parent_rate = cdce925_clk_best_parent_rate(hw, rate);
+ divider = cdce925_calc_divider(rate, l_parent_rate);
+ *parent_rate = l_parent_rate;
+ }
+ pr_debug("%s parent_rate=%lu pdiv=%u\n", __func__,
+ l_parent_rate, divider);
+ if (divider)
+ return (long)(l_parent_rate / divider);
+ return 0;
+}
+
+static int cdce925_clk_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct clk_cdce925_output *data = to_clk_cdce925_output(hw);
+
+ data->pdiv = cdce925_calc_divider(rate, parent_rate);
+ pr_debug("%s (index=%d parent_rate=%lu rate=%lu div=%d)\n",
__func__,
+ data->index, parent_rate, rate, data->pdiv);
+ return 0;
+}
+
+static const struct clk_ops cdce925_clk_ops = {
+ .prepare = cdce925_clk_prepare,
+ .unprepare = cdce925_clk_unprepare,
+ .recalc_rate = cdce925_clk_recalc_rate,
+ .round_rate = cdce925_clk_round_rate,
+ .set_rate = cdce925_clk_set_rate,
+};
+
+
+static u16 cdce925_y1_calc_divider(unsigned long rate,
+ unsigned long parent_rate)
+{
+ if (rate >= parent_rate)
+ return 1;
+ else if (rate) {
+ unsigned long divider = DIV_ROUND_CLOSEST(parent_rate,
rate);
+
+ if (divider > 0x3FF) /* Y1 has 10-bit divider */
+ divider = 0x3FF;
+ return (u16)divider;
+ } else
+ return 0;
+}
+
+static long cdce925_clk_y1_round_rate(struct clk_hw *hw, unsigned long
rate,
+ unsigned long *parent_rate)
+{
+ struct clk_cdce925_output *data = to_clk_cdce925_output(hw);
+ unsigned long l_parent_rate = *parent_rate;
+ u16 divider = cdce925_y1_calc_divider(rate, l_parent_rate);
+
+ pr_debug("%s (index=%d parent_rate=%lu rate=%lu pdiv=%u)\n",
__func__,
+ data->index, l_parent_rate, rate, divider);
+ if (divider)
+ return (long)(l_parent_rate / divider);
+ return 0;
+}
+
+static int cdce925_clk_y1_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct clk_cdce925_output *data = to_clk_cdce925_output(hw);
+
+ data->pdiv = cdce925_y1_calc_divider(rate, parent_rate);
+ pr_debug("%s (index=%d parent_rate=%lu rate=%lu div=%d)\n",
__func__,
+ data->index, parent_rate, rate, data->pdiv);
+ return 0;
+}
+
+static const struct clk_ops cdce925_clk_y1_ops = {
+ .prepare = cdce925_clk_prepare,
+ .unprepare = cdce925_clk_unprepare,
+ .recalc_rate = cdce925_clk_recalc_rate,
+ .round_rate = cdce925_clk_y1_round_rate,
+ .set_rate = cdce925_clk_y1_set_rate,
+};
+
+
+static struct regmap_config cdce925_regmap_config = {
+ .name = "configuration0",
+ .reg_bits = 8,
+ .val_bits = 8,
+ .cache_type = REGCACHE_RBTREE,
+ .max_register = 0x2F,
+};
+
+#define CDCE925_I2C_COMMAND_BLOCK_TRANSFER 0x00
+#define CDCE925_I2C_COMMAND_BYTE_TRANSFER 0x80
+
+static int cdce925_regmap_i2c_write(
+ void *context, const void *data, size_t count)
+{
+ struct device *dev = context;
+ struct i2c_client *i2c = to_i2c_client(dev);
+ int ret;
+ u8 reg_data[2];
+
+ if (count != 2)
+ return -ENOTSUPP;
+
+ /* First byte is command code */
+ reg_data[0] = CDCE925_I2C_COMMAND_BYTE_TRANSFER | ((u8 *)data)[0];
+ reg_data[1] = ((u8 *)data)[1];
+
+ dev_dbg(&i2c->dev, "%s(%u) %#x %#x\n", __func__, count,
+ reg_data[0], reg_data[1]);
+
+ ret = i2c_master_send(i2c, reg_data, count);
+ if (likely(ret == count))
+ return 0;
+ else if (ret < 0)
+ return ret;
+ else
+ return -EIO;
+}
+
+static int cdce925_regmap_i2c_read(void *context,
+ const void *reg, size_t reg_size, void *val, size_t val_size)
+{
+ struct device *dev = context;
+ struct i2c_client *i2c = to_i2c_client(dev);
+ struct i2c_msg xfer[2];
+ int ret;
+ u8 reg_data[2];
+
+ if (reg_size != 1)
+ return -ENOTSUPP;
+
+ xfer[0].addr = i2c->addr;
+ xfer[0].flags = 0;
+ xfer[0].buf = reg_data;
+ if (val_size == 1) {
+ reg_data[0] =
+ CDCE925_I2C_COMMAND_BYTE_TRANSFER | ((u8
*)reg)[0];
+ xfer[0].len = 1;
+ } else {
+ reg_data[0] =
+ CDCE925_I2C_COMMAND_BLOCK_TRANSFER | ((u8
*)reg)[0];
+ reg_data[1] = val_size;
+ xfer[0].len = 2;
+ }
+
+ xfer[1].addr = i2c->addr;
+ xfer[1].flags = I2C_M_RD;
+ xfer[1].len = val_size;
+ xfer[1].buf = val;
+
+ ret = i2c_transfer(i2c->adapter, xfer, 2);
+ if (likely(ret == 2)) {
+ dev_dbg(&i2c->dev, "%s(%u, %u) %#x %#x\n", __func__,
+ reg_size, val_size, reg_data[0], *((u8
*)val));
+ return 0;
+ } else if (ret < 0)
+ return ret;
+ else
+ return -EIO;
+}
+
+/* The CDCE925 uses a funky way to read/write registers. Bulk mode is
+ * just weird, so just use the single byte mode exclusively. */
+static struct regmap_bus regmap_cdce925_bus = {
+ .write = cdce925_regmap_i2c_write,
+ .read = cdce925_regmap_i2c_read,
+};
+
+static int cdce925_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct clk_cdce925_chip *data;
+ struct device_node *node = client->dev.of_node;
+ const char *parent_name;
+ struct clk_init_data init;
+ struct clk *clk;
+ u32 value;
+ int i;
+ int err;
+ struct device_node *np_output;
+ char child_name[6];
+
+ dev_dbg(&client->dev, "%s\n", __func__);
+ data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ data->i2c_client = client;
+ data->regmap = devm_regmap_init(&client->dev, &regmap_cdce925_bus,
+ &client->dev, &cdce925_regmap_config);
+ if (IS_ERR(data->regmap)) {
+ dev_err(&client->dev, "failed to allocate register
map\n");
+ return PTR_ERR(data->regmap);
+ }
+ i2c_set_clientdata(client, data);
+
+ parent_name = of_clk_get_parent_name(node, 0);
+ if (!parent_name) {
+ dev_err(&client->dev, "missing parent clock\n");
+ return -ENODEV;
+ }
+ dev_dbg(&client->dev, "parent is: %s\n", parent_name);
+
+ if (of_property_read_u32(node, "xtal-load-pf", &value) == 0)
+ regmap_write(data->regmap,
+ CDCE925_REG_XCSEL, (value << 3) & 0xF8);
+ /* PWDN bit */
+ regmap_update_bits(data->regmap, CDCE925_REG_GLOBAL1, BIT(4), 0);
+
+ /* Set input source for Y1 to be the XTAL */
+ regmap_update_bits(data->regmap, 0x02, BIT(7), 0);
+
+ init.ops = &cdce925_pll_ops;
+ init.flags = 0;
+ init.parent_names = &parent_name;
+ init.num_parents = parent_name ? 1 : 0;
+
+ /* Register PLL clocks */
+ for (i = 0; i < NUMBER_OF_PLLS; ++i) {
+ init.name = kasprintf(GFP_KERNEL, "%s.pll%d",
+ client->dev.of_node->name, i);
+ data->pll[i].chip = data;
+ data->pll[i].hw.init = &init;
+ data->pll[i].index = i;
+ clk = devm_clk_register(&client->dev, &data->pll[i].hw);
+ kfree(init.name); /* clock framework made a copy of the
name */
+ if (IS_ERR(clk)) {
+ dev_err(&client->dev, "Failed register PLL %d\n",
i);
+ err = PTR_ERR(clk);
+ goto error;
+ }
+ sprintf(child_name, "PLL%d", i+1);
+ np_output = of_get_child_by_name(node, child_name);
+ if (!np_output)
+ continue;
+ if (!of_property_read_u32(np_output,
+ "clock-frequency", &value)) {
+ err = clk_set_rate(clk, value);
+ if (err)
+ dev_err(&client->dev,
+ "unable to set PLL frequency
%ud\n",
+ value);
+ }
+ if (!of_property_read_u32(np_output,
+ "spread-spectrum", &value)) {
+ u8 flag = of_property_read_bool(np_output,
+ "spread-spectrum-center") ? 0x80 : 0x00;
+ regmap_update_bits(data->regmap,
+ 0x16 + (i*CDCE925_OFFSET_PLL),
+ 0x80, flag);
+ regmap_update_bits(data->regmap,
+ 0x12 + (i*CDCE925_OFFSET_PLL),
+ 0x07, value & 0x07);
+ }
+ }
+
+ /* Register output clock Y1 */
+ init.ops = &cdce925_clk_y1_ops;
+ init.flags = 0;
+ init.num_parents = 1;
+ init.parent_names = &parent_name; /* Mux Y1 to input */
+ init.name = kasprintf(GFP_KERNEL, "%s.Y1",
client->dev.of_node->name);
+ data->clk[0].chip = data;
+ data->clk[0].hw.init = &init;
+ data->clk[0].index = 0;
+ data->clk[0].pdiv = 1;
+ clk = devm_clk_register(&client->dev, &data->clk[0].hw);
+ kfree(init.name); /* clock framework made a copy of the name */
+ if (IS_ERR(clk)) {
+ dev_err(&client->dev, "clock registration Y1 failed\n");
+ err = PTR_ERR(clk);
+ goto error;
+ }
+
+ /* Register output clocks Y2 .. Y5*/
+ init.ops = &cdce925_clk_ops;
+ init.flags = CLK_SET_RATE_PARENT;
+ init.num_parents = 1;
+ for (i = 1; i < NUMBER_OF_OUTPUTS; ++i) {
+ init.name = kasprintf(GFP_KERNEL, "%s.Y%d",
+ client->dev.of_node->name, i+1);
+ data->clk[i].chip = data;
+ data->clk[i].hw.init = &init;
+ data->clk[i].index = i;
+ data->clk[i].pdiv = 1;
+ switch (i) {
+ case 1:
+ case 2:
+ /* Mux Y2/3 to PLL1 */
+ init.parent_names = &data->pll[0].hw.clk->name;
+ break;
+ case 3:
+ case 4:
+ /* Mux Y4/5 to PLL2 */
+ init.parent_names = &data->pll[1].hw.clk->name;
+ break;
+ }
+ clk = devm_clk_register(&client->dev, &data->clk[i].hw);
+ kfree(init.name); /* clock framework made a copy of the
name */
+ if (IS_ERR(clk)) {
+ dev_err(&client->dev, "clock registration
failed\n");
+ err = PTR_ERR(clk);
+ goto error;
+ }
+ }
+
+ /* Fetch settings from devicetree, if any */
+ for (i = 0; i < NUMBER_OF_OUTPUTS; ++i) {
+ sprintf(child_name, "Y%d", i+1);
+ np_output = of_get_child_by_name(node, child_name);
+ if (!np_output) {
+ /* Disable unlisted/unused clock outputs
explicitly */
+ cdce925_clk_unprepare(&data->clk[i].hw);
+ continue;
+ }
+ clk = data->clk[i].hw.clk;
+ if (!of_property_read_u32(np_output,
+ "clock-frequency", &value)) {
+ err = clk_set_rate(clk, value);
+ if (err)
+ dev_err(&client->dev,
+ "unable to set frequency %ud\n",
+ value);
+ }
+ if (of_property_read_bool(np_output, "clock-enabled")) {
+ err = clk_prepare_enable(clk);
+ if (err)
+ dev_err(&client->dev,
+ "Failed to enable clock %s\n",
+ init.name);
+ } else {
+ cdce925_clk_unprepare(&data->clk[i].hw);
+ }
+ err = of_clk_add_provider(np_output,
+ of_clk_src_simple_get, clk);
+ if (err)
+ dev_err(&client->dev,
+ "unable to add clock provider '%s'\n",
+ init.name);
+ }
+
+ return 0;
+
+error:
+ return err;
+}
+
+static const struct i2c_device_id cdce925_id[] = {
+ { "cdce925", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, cdce925_id);
+
+static const struct of_device_id clk_cdce925_of_match[] = {
+ { .compatible = "cdce925pw" },
+ { .compatible = "cdce925" },
+ { },
+};
+MODULE_DEVICE_TABLE(of, clk_cdce925_of_match);
+
+static struct i2c_driver cdce925_driver = {
+ .driver = {
+ .name = "cdce925",
+ .of_match_table = of_match_ptr(clk_cdce925_of_match),
+ },
+ .probe = cdce925_probe,
+ .id_table = cdce925_id,
+};
+module_i2c_driver(cdce925_driver);
+
+MODULE_AUTHOR("Mike Looijmans <mike.looijmans@xxxxxxxx>");
+MODULE_DESCRIPTION("cdce925 driver");
+MODULE_LICENSE("GPL");




Met vriendelijke groet / kind regards,

Mike Looijmans
System Expert


TOPIC Embedded Systems
Eindhovenseweg 32-C, NL-5683 KH Best
Postbus 440, NL-5680 AK Best
Telefoon: (+31) (0) 499 33 69 79
Telefax: (+31) (0) 499 33 69 70
E-mail: mike.looijmans@xxxxxxxx
Website: www.topic.nl

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Kind regards,

Mike Looijmans
System Expert

TOPIC Embedded Products
Eindhovenseweg 32-C, NL-5683 KH Best
Postbus 440, NL-5680 AK Best
Telefoon: +31 (0) 499 33 69 79
Telefax: +31 (0) 499 33 69 70
E-mail: mike.looijmans@xxxxxxxxxxxxxxxxx
Website: www.topicproducts.com

Please consider the environment before printing this e-mail

Please visit us at the Hannover Messe which will be held from 13.04.2015 till 17.04.2015, Hall 2, Stand C12, Holland High Tech House
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