Add a driver for SILabs 570, 571, 598, 599 programmable oscillators.
The devices generate low-jitter clock signals and are reprogrammable via
an I2C interface.
Cc: Guenter Roeck <[email protected]>
Signed-off-by: Soren Brinkmann <[email protected]>
---
v5:
- fix typo in bindings documentation
- mention the unit for the 'temperature-stability' property
- remove calls to clk_unregister() (the device managed code takes care
of it)
v4:
- actually check and handle error on clk_set_rate() call
v3:
- add delay in the path for small frequency changes, which can take up
to 100us according to the data sheet
- use real range for usleep_range() argument
- use dev_err() over dev_warn() in set_rate()
- add list of applicable devices for 7ppm DT prop
- remove comments regarding platform data
- ignore 7ppm DT prop for incompatible devices
- replace raw numbers with #defines
- convert DT prop 'temperature-stability' from boolean to u32
- make 'temperature-stability' DT prop required (actually not fully
true, for 59x it is ignored and the driver does not require its
presence)
v2:
- document clock-output-names in bindings documentation
- don't use wildcards in compatibility string
- change Kconfig entry to "... 570 and compatible devices"
- change some indentation flaws
- use 10000 as MIN and MAX value in usleep_range
- fail probe() if 'factory-fout' is not provided in DT
- default factory fout #defines removed
- use i2c driver_data instead of OF data
- remove some related structs and data
- rename DT property 'initial-fout' => 'clock-frequency' (like si5351
driver)
- add some more details regarding the 'factory-fout' DT property
---
.../devicetree/bindings/clock/silabs,si570.txt | 39 ++
drivers/clk/Kconfig | 10 +
drivers/clk/Makefile | 1 +
drivers/clk/clk-si570.c | 531 +++++++++++++++++++++
4 files changed, 581 insertions(+)
create mode 100644 Documentation/devicetree/bindings/clock/silabs,si570.txt
create mode 100644 drivers/clk/clk-si570.c
diff --git a/Documentation/devicetree/bindings/clock/silabs,si570.txt b/Documentation/devicetree/bindings/clock/silabs,si570.txt
new file mode 100644
index 0000000..c09f21e
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/silabs,si570.txt
@@ -0,0 +1,39 @@
+Binding for Silicon Labs 570, 571, 598 and 599 programmable
+I2C clock generators.
+
+Reference
+This binding uses the common clock binding[1]. Details about the devices can be
+found in the data sheets[2][3].
+
+[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
+[2] Si570/571 Data Sheet
+ http://www.silabs.com/Support%20Documents/TechnicalDocs/si570.pdf
+[3] Si598/599 Data Sheet
+ http://www.silabs.com/Support%20Documents/TechnicalDocs/si598-99.pdf
+
+Required properties:
+ - compatible: Shall be one of "silabs,si570", "silabs,si571",
+ "silabs,si598", "silabs,si599"
+ - reg: I2C device address.
+ - #clock-cells: From common clock bindings: Shall be 0.
+ - factory-fout: Factory set default frequency. This frequency is part specific.
+ The correct frequency for the part used has to be provided in
+ order to generate the correct output frequencies. For more
+ details, please refer to the data sheet.
+ - temperature-stability: Temperature stability of the device in PPM. Should be
+ one of: 7, 20, 50 or 100.
+
+Optional properties:
+ - clock-output-names: From common clock bindings. Recommended to be "si570".
+ - 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.
+
+Example:
+ si570: clock-generator@5d {
+ #clock-cells = <0>;
+ compatible = "silabs,si570";
+ temperature-stability = <50>;
+ reg = <0x5d>;
+ factory-fout = <156250000>;
+ };
diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
index 279407a..349b88a 100644
--- a/drivers/clk/Kconfig
+++ b/drivers/clk/Kconfig
@@ -64,6 +64,16 @@ config COMMON_CLK_SI5351
This driver supports Silicon Labs 5351A/B/C programmable clock
generators.
+config COMMON_CLK_SI570
+ tristate "Clock driver for SiLabs 570 and compatible devices"
+ depends on I2C
+ depends on OF
+ select REGMAP_I2C
+ help
+ ---help---
+ This driver supports Silicon Labs 570/571/598/599 programmable
+ clock generators.
+
config COMMON_CLK_S2MPS11
tristate "Clock driver for S2MPS11 MFD"
depends on MFD_SEC_CORE
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index 7b11106..c0e94b3 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -40,6 +40,7 @@ obj-$(CONFIG_COMMON_CLK_AXI_CLKGEN) += clk-axi-clkgen.o
obj-$(CONFIG_COMMON_CLK_WM831X) += clk-wm831x.o
obj-$(CONFIG_COMMON_CLK_MAX77686) += clk-max77686.o
obj-$(CONFIG_COMMON_CLK_SI5351) += clk-si5351.o
+obj-$(CONFIG_COMMON_CLK_SI570) += clk-si570.o
obj-$(CONFIG_COMMON_CLK_S2MPS11) += clk-s2mps11.o
obj-$(CONFIG_CLK_TWL6040) += clk-twl6040.o
obj-$(CONFIG_CLK_PPC_CORENET) += clk-ppc-corenet.o
diff --git a/drivers/clk/clk-si570.c b/drivers/clk/clk-si570.c
new file mode 100644
index 0000000..5d0ac9f
--- /dev/null
+++ b/drivers/clk/clk-si570.c
@@ -0,0 +1,531 @@
+/*
+ * Driver for Silicon Labs Si570/Si571 Programmable XO/VCXO
+ *
+ * Copyright (C) 2010, 2011 Ericsson AB.
+ * Copyright (C) 2011 Guenter Roeck.
+ * Copyright (C) 2011 - 2013 Xilinx Inc.
+ *
+ * Author: Guenter Roeck <[email protected]>
+ * Sören Brinkmann <[email protected]>
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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.
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+/* Si570 registers */
+#define SI570_REG_HS_N1 7
+#define SI570_REG_N1_RFREQ0 8
+#define SI570_REG_RFREQ1 9
+#define SI570_REG_RFREQ2 10
+#define SI570_REG_RFREQ3 11
+#define SI570_REG_RFREQ4 12
+#define SI570_REG_CONTROL 135
+#define SI570_REG_FREEZE_DCO 137
+#define SI570_DIV_OFFSET_7PPM 6
+
+#define HS_DIV_SHIFT 5
+#define HS_DIV_MASK 0xe0
+#define HS_DIV_OFFSET 4
+#define N1_6_2_MASK 0x1f
+#define N1_1_0_MASK 0xc0
+#define RFREQ_37_32_MASK 0x3f
+
+#define SI570_MIN_FREQ 10000000L
+#define SI570_MAX_FREQ 1417500000L
+#define SI598_MAX_FREQ 525000000L
+
+#define FDCO_MIN 4850000000LL
+#define FDCO_MAX 5670000000LL
+
+#define SI570_CNTRL_RECALL (1 << 0)
+#define SI570_CNTRL_FREEZE_M (1 << 5)
+#define SI570_CNTRL_NEWFREQ (1 << 6)
+
+#define SI570_FREEZE_DCO (1 << 4)
+
+/**
+ * struct clk_si570:
+ * @hw: Clock hw struct
+ * @regmap: Device's regmap
+ * @div_offset: Rgister offset for dividers
+ * @max_freq: Maximum frequency for this device
+ * @fxtal: Factory xtal frequency
+ * @n1: Clock divider N1
+ * @hs_div: Clock divider HSDIV
+ * @rfreq: Clock multiplier RFREQ
+ * @frequency: Current output frequency
+ * @i2c_client: I2C client pointer
+ */
+struct clk_si570 {
+ struct clk_hw hw;
+ struct regmap *regmap;
+ unsigned int div_offset;
+ u64 max_freq;
+ u64 fxtal;
+ unsigned int n1;
+ unsigned int hs_div;
+ u64 rfreq;
+ u64 frequency;
+ struct i2c_client *i2c_client;
+};
+#define to_clk_si570(_hw) container_of(_hw, struct clk_si570, hw)
+
+enum clk_si570_variant {
+ si57x,
+ si59x
+};
+
+/**
+ * si570_get_divs() - Read clock dividers from HW
+ * @data: Pointer to struct clk_si570
+ * @rfreq: Fractional multiplier (output)
+ * @n1: Divider N1 (output)
+ * @hs_div: Divider HSDIV (output)
+ * Returns 0 on success, negative errno otherwise.
+ *
+ * Retrieve clock dividers and multipliers from the HW.
+ */
+static int si570_get_divs(struct clk_si570 *data, u64 *rfreq,
+ unsigned int *n1, unsigned int *hs_div)
+{
+ int err;
+ u8 reg[6];
+ u64 tmp;
+
+ err = regmap_bulk_read(data->regmap, SI570_REG_HS_N1 + data->div_offset,
+ reg, ARRAY_SIZE(reg));
+ if (err)
+ return err;
+
+ *hs_div = ((reg[0] & HS_DIV_MASK) >> HS_DIV_SHIFT) + HS_DIV_OFFSET;
+ *n1 = ((reg[0] & N1_6_2_MASK) << 2) + ((reg[1] & N1_1_0_MASK) >> 6) + 1;
+ /* Handle invalid cases */
+ if (*n1 > 1)
+ *n1 &= ~1;
+
+ tmp = reg[1] & RFREQ_37_32_MASK;
+ tmp = (tmp << 8) + reg[2];
+ tmp = (tmp << 8) + reg[3];
+ tmp = (tmp << 8) + reg[4];
+ tmp = (tmp << 8) + reg[5];
+ *rfreq = tmp;
+
+ return 0;
+}
+
+/**
+ * si570_get_defaults() - Get default values
+ * @data: Driver data structure
+ * @fout: Factory frequency output
+ * Returns 0 on success, negative errno otherwise.
+ */
+static int si570_get_defaults(struct clk_si570 *data, u64 fout)
+{
+ int err;
+ u64 fdco;
+
+ regmap_write(data->regmap, SI570_REG_CONTROL, SI570_CNTRL_RECALL);
+
+ err = si570_get_divs(data, &data->rfreq, &data->n1, &data->hs_div);
+ if (err)
+ return err;
+
+ /*
+ * Accept optional precision loss to avoid arithmetic overflows.
+ * Acceptable per Silicon Labs Application Note AN334.
+ */
+ fdco = fout * data->n1 * data->hs_div;
+ if (fdco >= (1LL << 36))
+ data->fxtal = div64_u64(fdco << 24, data->rfreq >> 4);
+ else
+ data->fxtal = div64_u64(fdco << 28, data->rfreq);
+
+ data->frequency = fout;
+
+ return 0;
+}
+
+/**
+ * si570_update_rfreq() - Update clock multiplier
+ * @data: Driver data structure
+ * Passes on regmap_bulk_write() return value.
+ */
+static int si570_update_rfreq(struct clk_si570 *data)
+{
+ u8 reg[5];
+
+ reg[0] = ((data->n1 - 1) << 6) |
+ ((data->rfreq >> 32) & RFREQ_37_32_MASK);
+ reg[1] = (data->rfreq >> 24) & 0xff;
+ reg[2] = (data->rfreq >> 16) & 0xff;
+ reg[3] = (data->rfreq >> 8) & 0xff;
+ reg[4] = data->rfreq & 0xff;
+
+ return regmap_bulk_write(data->regmap, SI570_REG_N1_RFREQ0 +
+ data->div_offset, reg, ARRAY_SIZE(reg));
+}
+
+/**
+ * si570_calc_divs() - Caluclate clock dividers
+ * @frequency: Target frequency
+ * @data: Driver data structure
+ * @out_rfreq: RFREG fractional multiplier (output)
+ * @out_n1: Clock divider N1 (output)
+ * @out_hs_div: Clock divider HSDIV (output)
+ * Returns 0 on success, negative errno otherwise.
+ *
+ * Calculate the clock dividers (@out_hs_div, @out_n1) and clock multiplier
+ * (@out_rfreq) for a given target @frequency.
+ */
+static int si570_calc_divs(unsigned long frequency, struct clk_si570 *data,
+ u64 *out_rfreq, unsigned int *out_n1, unsigned int *out_hs_div)
+{
+ int i;
+ unsigned int n1, hs_div;
+ u64 fdco, best_fdco = ULLONG_MAX;
+ static const uint8_t si570_hs_div_values[] = { 11, 9, 7, 6, 5, 4 };
+
+ for (i = 0; i < ARRAY_SIZE(si570_hs_div_values); i++) {
+ hs_div = si570_hs_div_values[i];
+ /* Calculate lowest possible value for n1 */
+ n1 = div_u64(div_u64(FDCO_MIN, hs_div), frequency);
+ if (!n1 || (n1 & 1))
+ n1++;
+ while (n1 <= 128) {
+ fdco = (u64)frequency * (u64)hs_div * (u64)n1;
+ if (fdco > FDCO_MAX)
+ break;
+ if (fdco >= FDCO_MIN && fdco < best_fdco) {
+ *out_n1 = n1;
+ *out_hs_div = hs_div;
+ *out_rfreq = div64_u64(fdco << 28, data->fxtal);
+ best_fdco = fdco;
+ }
+ n1 += (n1 == 1 ? 1 : 2);
+ }
+ }
+
+ if (best_fdco == ULLONG_MAX)
+ return -EINVAL;
+
+ return 0;
+}
+
+static unsigned long si570_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ int err;
+ u64 rfreq, rate;
+ unsigned int n1, hs_div;
+ struct clk_si570 *data = to_clk_si570(hw);
+
+ err = si570_get_divs(data, &rfreq, &n1, &hs_div);
+ if (err) {
+ dev_err(&data->i2c_client->dev, "unable to recalc rate\n");
+ return data->frequency;
+ }
+
+ rfreq = div_u64(rfreq, hs_div * n1);
+ rate = (data->fxtal * rfreq) >> 28;
+
+ return rate;
+}
+
+static long si570_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *parent_rate)
+{
+ int err;
+ u64 rfreq;
+ unsigned int n1, hs_div;
+ struct clk_si570 *data = to_clk_si570(hw);
+
+ if (!rate)
+ return 0;
+
+ if (div64_u64(abs(rate - data->frequency) * 10000LL,
+ data->frequency) < 35) {
+ rfreq = div64_u64((data->rfreq * rate) +
+ div64_u64(data->frequency, 2), data->frequency);
+ n1 = data->n1;
+ hs_div = data->hs_div;
+
+ } else {
+ err = si570_calc_divs(rate, data, &rfreq, &n1, &hs_div);
+ if (err) {
+ dev_err(&data->i2c_client->dev,
+ "unable to round rate\n");
+ return 0;
+ }
+ }
+
+ return rate;
+}
+
+/**
+ * si570_set_frequency() - Adjust output frequency
+ * @data: Driver data structure
+ * @frequency: Target frequency
+ * Returns 0 on success.
+ *
+ * Update output frequency for big frequency changes (> 3,500 ppm).
+ */
+static int si570_set_frequency(struct clk_si570 *data, unsigned long frequency)
+{
+ int err;
+
+ err = si570_calc_divs(frequency, data, &data->rfreq, &data->n1,
+ &data->hs_div);
+ if (err)
+ return err;
+
+ /*
+ * The DCO reg should be accessed with a read-modify-write operation
+ * per AN334
+ */
+ regmap_write(data->regmap, SI570_REG_FREEZE_DCO, SI570_FREEZE_DCO);
+ regmap_write(data->regmap, SI570_REG_HS_N1 + data->div_offset,
+ ((data->hs_div - HS_DIV_OFFSET) << HS_DIV_SHIFT) |
+ (((data->n1 - 1) >> 2) & N1_6_2_MASK));
+ si570_update_rfreq(data);
+ regmap_write(data->regmap, SI570_REG_FREEZE_DCO, 0);
+ regmap_write(data->regmap, SI570_REG_CONTROL, SI570_CNTRL_NEWFREQ);
+
+ /* Applying a new frequency can take up to 10ms */
+ usleep_range(10000, 12000);
+
+ return 0;
+}
+
+/**
+ * si570_set_frequency_small() - Adjust output frequency
+ * @data: Driver data structure
+ * @frequency: Target frequency
+ * Returns 0 on success.
+ *
+ * Update output frequency for small frequency changes (< 3,500 ppm).
+ */
+static int si570_set_frequency_small(struct clk_si570 *data,
+ unsigned long frequency)
+{
+ /*
+ * This is a re-implementation of DIV_ROUND_CLOSEST
+ * using the div64_u64 function lieu of letting the compiler
+ * insert EABI calls
+ */
+ data->rfreq = div64_u64((data->rfreq * frequency) +
+ div_u64(data->frequency, 2), data->frequency);
+ regmap_write(data->regmap, SI570_REG_CONTROL, SI570_CNTRL_FREEZE_M);
+ si570_update_rfreq(data);
+ regmap_write(data->regmap, SI570_REG_CONTROL, 0);
+
+ /* Applying a new frequency (small change) can take up to 100us */
+ usleep_range(100, 200);
+
+ return 0;
+}
+
+static int si570_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct clk_si570 *data = to_clk_si570(hw);
+ struct i2c_client *client = data->i2c_client;
+ int err;
+
+ if (rate < SI570_MIN_FREQ || rate > data->max_freq) {
+ dev_err(&client->dev,
+ "requested frequency %lu Hz is out of range\n", rate);
+ return -EINVAL;
+ }
+
+ if (div64_u64(abs(rate - data->frequency) * 10000LL,
+ data->frequency) < 35)
+ err = si570_set_frequency_small(data, rate);
+ else
+ err = si570_set_frequency(data, rate);
+
+ if (err)
+ return err;
+
+ data->frequency = rate;
+
+ return 0;
+}
+
+static const struct clk_ops si570_clk_ops = {
+ .recalc_rate = si570_recalc_rate,
+ .round_rate = si570_round_rate,
+ .set_rate = si570_set_rate,
+};
+
+static bool si570_regmap_is_volatile(struct device *dev, unsigned int reg)
+{
+ switch (reg) {
+ case SI570_REG_CONTROL:
+ return true;
+ default:
+ return false;
+ }
+}
+
+static bool si570_regmap_is_writeable(struct device *dev, unsigned int reg)
+{
+ switch (reg) {
+ case SI570_REG_HS_N1 ... (SI570_REG_RFREQ4 + SI570_DIV_OFFSET_7PPM):
+ case SI570_REG_CONTROL:
+ case SI570_REG_FREEZE_DCO:
+ return true;
+ default:
+ return false;
+ }
+}
+
+static struct regmap_config si570_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .cache_type = REGCACHE_RBTREE,
+ .max_register = 137,
+ .writeable_reg = si570_regmap_is_writeable,
+ .volatile_reg = si570_regmap_is_volatile,
+};
+
+static int si570_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct clk_si570 *data;
+ struct clk_init_data init;
+ struct clk *clk;
+ u32 initial_fout, factory_fout, stability;
+ int err;
+ enum clk_si570_variant variant = id->driver_data;
+
+ data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ init.ops = &si570_clk_ops;
+ init.flags = CLK_IS_ROOT;
+ init.num_parents = 0;
+ data->hw.init = &init;
+ data->i2c_client = client;
+
+ if (variant == si57x) {
+ err = of_property_read_u32(client->dev.of_node,
+ "temperature-stability", &stability);
+ if (err) {
+ dev_err(&client->dev,
+ "'temperature-stability' property missing\n");
+ return err;
+ }
+ /* adjust register offsets for 7ppm devices */
+ if (stability == 7)
+ data->div_offset = SI570_DIV_OFFSET_7PPM;
+
+ data->max_freq = SI570_MAX_FREQ;
+ } else {
+ data->max_freq = SI598_MAX_FREQ;
+ }
+
+ if (of_property_read_string(client->dev.of_node, "clock-output-names",
+ &init.name))
+ init.name = client->dev.of_node->name;
+
+ err = of_property_read_u32(client->dev.of_node, "factory-fout",
+ &factory_fout);
+ if (err) {
+ dev_err(&client->dev, "'factory-fout' property missing\n");
+ return err;
+ }
+
+ data->regmap = devm_regmap_init_i2c(client, &si570_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);
+ err = si570_get_defaults(data, factory_fout);
+ if (err)
+ return err;
+
+ clk = devm_clk_register(&client->dev, &data->hw);
+ if (IS_ERR(clk)) {
+ dev_err(&client->dev, "clock registration failed\n");
+ return PTR_ERR(clk);
+ }
+ err = of_clk_add_provider(client->dev.of_node, of_clk_src_simple_get,
+ clk);
+ if (err) {
+ dev_err(&client->dev, "unable to add clk provider\n");
+ return err;
+ }
+
+ /* Read the requested initial output frequency from device tree */
+ if (!of_property_read_u32(client->dev.of_node, "clock-frequency",
+ &initial_fout)) {
+ err = clk_set_rate(clk, initial_fout);
+ if (err) {
+ of_clk_del_provider(client->dev.of_node);
+ return err;
+ }
+ }
+
+ /* Display a message indicating that we've successfully registered */
+ dev_info(&client->dev, "registered, current frequency %llu Hz\n",
+ data->frequency);
+
+ return 0;
+}
+
+static int si570_remove(struct i2c_client *client)
+{
+ of_clk_del_provider(client->dev.of_node);
+ return 0;
+}
+
+static const struct i2c_device_id si570_id[] = {
+ { "si570", si57x },
+ { "si571", si57x },
+ { "si598", si59x },
+ { "si599", si59x },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, si570_id);
+
+static const struct of_device_id clk_si570_of_match[] = {
+ { .compatible = "silabs,si570" },
+ { .compatible = "silabs,si571" },
+ { .compatible = "silabs,si598" },
+ { .compatible = "silabs,si599" },
+ { },
+};
+MODULE_DEVICE_TABLE(of, clk_si570_of_match);
+
+static struct i2c_driver si570_driver = {
+ .driver = {
+ .name = "si570",
+ .of_match_table = of_match_ptr(clk_si570_of_match),
+ },
+ .probe = si570_probe,
+ .remove = si570_remove,
+ .id_table = si570_id,
+};
+module_i2c_driver(si570_driver);
+
+MODULE_AUTHOR("Guenter Roeck <[email protected]>");
+MODULE_AUTHOR("Soeren Brinkmann <[email protected]");
+MODULE_DESCRIPTION("Si570 driver");
+MODULE_LICENSE("GPL");
--
1.8.4
On 09/21/2013 04:40 PM, Soren Brinkmann wrote:
> Add a driver for SILabs 570, 571, 598, 599 programmable oscillators.
> The devices generate low-jitter clock signals and are reprogrammable via
> an I2C interface.
>
> Cc: Guenter Roeck <[email protected]>
> Signed-off-by: Soren Brinkmann <[email protected]>
Looks good to me. Thanks a lot for picking this up.
Reviewed-by: Guenter Roeck <[email protected]>
Guenter
Hi Mike,
could you please comment on this/apply it to clk-next?
Thanks,
Sören
On Sat, Sep 21, 2013 at 04:40:39PM -0700, Soren Brinkmann wrote:
> Add a driver for SILabs 570, 571, 598, 599 programmable oscillators.
> The devices generate low-jitter clock signals and are reprogrammable via
> an I2C interface.
>
> Cc: Guenter Roeck <[email protected]>
> Signed-off-by: Soren Brinkmann <[email protected]>
> ---
> v5:
> - fix typo in bindings documentation
> - mention the unit for the 'temperature-stability' property
> - remove calls to clk_unregister() (the device managed code takes care
> of it)
>
> v4:
> - actually check and handle error on clk_set_rate() call
>
> v3:
> - add delay in the path for small frequency changes, which can take up
> to 100us according to the data sheet
> - use real range for usleep_range() argument
> - use dev_err() over dev_warn() in set_rate()
> - add list of applicable devices for 7ppm DT prop
> - remove comments regarding platform data
> - ignore 7ppm DT prop for incompatible devices
> - replace raw numbers with #defines
> - convert DT prop 'temperature-stability' from boolean to u32
> - make 'temperature-stability' DT prop required (actually not fully
> true, for 59x it is ignored and the driver does not require its
> presence)
>
> v2:
> - document clock-output-names in bindings documentation
> - don't use wildcards in compatibility string
> - change Kconfig entry to "... 570 and compatible devices"
> - change some indentation flaws
> - use 10000 as MIN and MAX value in usleep_range
> - fail probe() if 'factory-fout' is not provided in DT
> - default factory fout #defines removed
> - use i2c driver_data instead of OF data
> - remove some related structs and data
> - rename DT property 'initial-fout' => 'clock-frequency' (like si5351
> driver)
> - add some more details regarding the 'factory-fout' DT property
> ---
> .../devicetree/bindings/clock/silabs,si570.txt | 39 ++
> drivers/clk/Kconfig | 10 +
> drivers/clk/Makefile | 1 +
> drivers/clk/clk-si570.c | 531 +++++++++++++++++++++
> 4 files changed, 581 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/clock/silabs,si570.txt
> create mode 100644 drivers/clk/clk-si570.c
>
> diff --git a/Documentation/devicetree/bindings/clock/silabs,si570.txt b/Documentation/devicetree/bindings/clock/silabs,si570.txt
> new file mode 100644
> index 0000000..c09f21e
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/clock/silabs,si570.txt
> @@ -0,0 +1,39 @@
> +Binding for Silicon Labs 570, 571, 598 and 599 programmable
> +I2C clock generators.
> +
> +Reference
> +This binding uses the common clock binding[1]. Details about the devices can be
> +found in the data sheets[2][3].
> +
> +[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
> +[2] Si570/571 Data Sheet
> + http://www.silabs.com/Support%20Documents/TechnicalDocs/si570.pdf
> +[3] Si598/599 Data Sheet
> + http://www.silabs.com/Support%20Documents/TechnicalDocs/si598-99.pdf
> +
> +Required properties:
> + - compatible: Shall be one of "silabs,si570", "silabs,si571",
> + "silabs,si598", "silabs,si599"
> + - reg: I2C device address.
> + - #clock-cells: From common clock bindings: Shall be 0.
> + - factory-fout: Factory set default frequency. This frequency is part specific.
> + The correct frequency for the part used has to be provided in
> + order to generate the correct output frequencies. For more
> + details, please refer to the data sheet.
> + - temperature-stability: Temperature stability of the device in PPM. Should be
> + one of: 7, 20, 50 or 100.
> +
> +Optional properties:
> + - clock-output-names: From common clock bindings. Recommended to be "si570".
> + - 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.
> +
> +Example:
> + si570: clock-generator@5d {
> + #clock-cells = <0>;
> + compatible = "silabs,si570";
> + temperature-stability = <50>;
> + reg = <0x5d>;
> + factory-fout = <156250000>;
> + };
> diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
> index 279407a..349b88a 100644
> --- a/drivers/clk/Kconfig
> +++ b/drivers/clk/Kconfig
> @@ -64,6 +64,16 @@ config COMMON_CLK_SI5351
> This driver supports Silicon Labs 5351A/B/C programmable clock
> generators.
>
> +config COMMON_CLK_SI570
> + tristate "Clock driver for SiLabs 570 and compatible devices"
> + depends on I2C
> + depends on OF
> + select REGMAP_I2C
> + help
> + ---help---
> + This driver supports Silicon Labs 570/571/598/599 programmable
> + clock generators.
> +
> config COMMON_CLK_S2MPS11
> tristate "Clock driver for S2MPS11 MFD"
> depends on MFD_SEC_CORE
> diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
> index 7b11106..c0e94b3 100644
> --- a/drivers/clk/Makefile
> +++ b/drivers/clk/Makefile
> @@ -40,6 +40,7 @@ obj-$(CONFIG_COMMON_CLK_AXI_CLKGEN) += clk-axi-clkgen.o
> obj-$(CONFIG_COMMON_CLK_WM831X) += clk-wm831x.o
> obj-$(CONFIG_COMMON_CLK_MAX77686) += clk-max77686.o
> obj-$(CONFIG_COMMON_CLK_SI5351) += clk-si5351.o
> +obj-$(CONFIG_COMMON_CLK_SI570) += clk-si570.o
> obj-$(CONFIG_COMMON_CLK_S2MPS11) += clk-s2mps11.o
> obj-$(CONFIG_CLK_TWL6040) += clk-twl6040.o
> obj-$(CONFIG_CLK_PPC_CORENET) += clk-ppc-corenet.o
> diff --git a/drivers/clk/clk-si570.c b/drivers/clk/clk-si570.c
> new file mode 100644
> index 0000000..5d0ac9f
> --- /dev/null
> +++ b/drivers/clk/clk-si570.c
> @@ -0,0 +1,531 @@
> +/*
> + * Driver for Silicon Labs Si570/Si571 Programmable XO/VCXO
> + *
> + * Copyright (C) 2010, 2011 Ericsson AB.
> + * Copyright (C) 2011 Guenter Roeck.
> + * Copyright (C) 2011 - 2013 Xilinx Inc.
> + *
> + * Author: Guenter Roeck <[email protected]>
> + * Sören Brinkmann <[email protected]>
> + *
> + * 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; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * 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.
> + */
> +
> +#include <linux/clk-provider.h>
> +#include <linux/delay.h>
> +#include <linux/module.h>
> +#include <linux/i2c.h>
> +#include <linux/regmap.h>
> +#include <linux/slab.h>
> +
> +/* Si570 registers */
> +#define SI570_REG_HS_N1 7
> +#define SI570_REG_N1_RFREQ0 8
> +#define SI570_REG_RFREQ1 9
> +#define SI570_REG_RFREQ2 10
> +#define SI570_REG_RFREQ3 11
> +#define SI570_REG_RFREQ4 12
> +#define SI570_REG_CONTROL 135
> +#define SI570_REG_FREEZE_DCO 137
> +#define SI570_DIV_OFFSET_7PPM 6
> +
> +#define HS_DIV_SHIFT 5
> +#define HS_DIV_MASK 0xe0
> +#define HS_DIV_OFFSET 4
> +#define N1_6_2_MASK 0x1f
> +#define N1_1_0_MASK 0xc0
> +#define RFREQ_37_32_MASK 0x3f
> +
> +#define SI570_MIN_FREQ 10000000L
> +#define SI570_MAX_FREQ 1417500000L
> +#define SI598_MAX_FREQ 525000000L
> +
> +#define FDCO_MIN 4850000000LL
> +#define FDCO_MAX 5670000000LL
> +
> +#define SI570_CNTRL_RECALL (1 << 0)
> +#define SI570_CNTRL_FREEZE_M (1 << 5)
> +#define SI570_CNTRL_NEWFREQ (1 << 6)
> +
> +#define SI570_FREEZE_DCO (1 << 4)
> +
> +/**
> + * struct clk_si570:
> + * @hw: Clock hw struct
> + * @regmap: Device's regmap
> + * @div_offset: Rgister offset for dividers
> + * @max_freq: Maximum frequency for this device
> + * @fxtal: Factory xtal frequency
> + * @n1: Clock divider N1
> + * @hs_div: Clock divider HSDIV
> + * @rfreq: Clock multiplier RFREQ
> + * @frequency: Current output frequency
> + * @i2c_client: I2C client pointer
> + */
> +struct clk_si570 {
> + struct clk_hw hw;
> + struct regmap *regmap;
> + unsigned int div_offset;
> + u64 max_freq;
> + u64 fxtal;
> + unsigned int n1;
> + unsigned int hs_div;
> + u64 rfreq;
> + u64 frequency;
> + struct i2c_client *i2c_client;
> +};
> +#define to_clk_si570(_hw) container_of(_hw, struct clk_si570, hw)
> +
> +enum clk_si570_variant {
> + si57x,
> + si59x
> +};
> +
> +/**
> + * si570_get_divs() - Read clock dividers from HW
> + * @data: Pointer to struct clk_si570
> + * @rfreq: Fractional multiplier (output)
> + * @n1: Divider N1 (output)
> + * @hs_div: Divider HSDIV (output)
> + * Returns 0 on success, negative errno otherwise.
> + *
> + * Retrieve clock dividers and multipliers from the HW.
> + */
> +static int si570_get_divs(struct clk_si570 *data, u64 *rfreq,
> + unsigned int *n1, unsigned int *hs_div)
> +{
> + int err;
> + u8 reg[6];
> + u64 tmp;
> +
> + err = regmap_bulk_read(data->regmap, SI570_REG_HS_N1 + data->div_offset,
> + reg, ARRAY_SIZE(reg));
> + if (err)
> + return err;
> +
> + *hs_div = ((reg[0] & HS_DIV_MASK) >> HS_DIV_SHIFT) + HS_DIV_OFFSET;
> + *n1 = ((reg[0] & N1_6_2_MASK) << 2) + ((reg[1] & N1_1_0_MASK) >> 6) + 1;
> + /* Handle invalid cases */
> + if (*n1 > 1)
> + *n1 &= ~1;
> +
> + tmp = reg[1] & RFREQ_37_32_MASK;
> + tmp = (tmp << 8) + reg[2];
> + tmp = (tmp << 8) + reg[3];
> + tmp = (tmp << 8) + reg[4];
> + tmp = (tmp << 8) + reg[5];
> + *rfreq = tmp;
> +
> + return 0;
> +}
> +
> +/**
> + * si570_get_defaults() - Get default values
> + * @data: Driver data structure
> + * @fout: Factory frequency output
> + * Returns 0 on success, negative errno otherwise.
> + */
> +static int si570_get_defaults(struct clk_si570 *data, u64 fout)
> +{
> + int err;
> + u64 fdco;
> +
> + regmap_write(data->regmap, SI570_REG_CONTROL, SI570_CNTRL_RECALL);
> +
> + err = si570_get_divs(data, &data->rfreq, &data->n1, &data->hs_div);
> + if (err)
> + return err;
> +
> + /*
> + * Accept optional precision loss to avoid arithmetic overflows.
> + * Acceptable per Silicon Labs Application Note AN334.
> + */
> + fdco = fout * data->n1 * data->hs_div;
> + if (fdco >= (1LL << 36))
> + data->fxtal = div64_u64(fdco << 24, data->rfreq >> 4);
> + else
> + data->fxtal = div64_u64(fdco << 28, data->rfreq);
> +
> + data->frequency = fout;
> +
> + return 0;
> +}
> +
> +/**
> + * si570_update_rfreq() - Update clock multiplier
> + * @data: Driver data structure
> + * Passes on regmap_bulk_write() return value.
> + */
> +static int si570_update_rfreq(struct clk_si570 *data)
> +{
> + u8 reg[5];
> +
> + reg[0] = ((data->n1 - 1) << 6) |
> + ((data->rfreq >> 32) & RFREQ_37_32_MASK);
> + reg[1] = (data->rfreq >> 24) & 0xff;
> + reg[2] = (data->rfreq >> 16) & 0xff;
> + reg[3] = (data->rfreq >> 8) & 0xff;
> + reg[4] = data->rfreq & 0xff;
> +
> + return regmap_bulk_write(data->regmap, SI570_REG_N1_RFREQ0 +
> + data->div_offset, reg, ARRAY_SIZE(reg));
> +}
> +
> +/**
> + * si570_calc_divs() - Caluclate clock dividers
> + * @frequency: Target frequency
> + * @data: Driver data structure
> + * @out_rfreq: RFREG fractional multiplier (output)
> + * @out_n1: Clock divider N1 (output)
> + * @out_hs_div: Clock divider HSDIV (output)
> + * Returns 0 on success, negative errno otherwise.
> + *
> + * Calculate the clock dividers (@out_hs_div, @out_n1) and clock multiplier
> + * (@out_rfreq) for a given target @frequency.
> + */
> +static int si570_calc_divs(unsigned long frequency, struct clk_si570 *data,
> + u64 *out_rfreq, unsigned int *out_n1, unsigned int *out_hs_div)
> +{
> + int i;
> + unsigned int n1, hs_div;
> + u64 fdco, best_fdco = ULLONG_MAX;
> + static const uint8_t si570_hs_div_values[] = { 11, 9, 7, 6, 5, 4 };
> +
> + for (i = 0; i < ARRAY_SIZE(si570_hs_div_values); i++) {
> + hs_div = si570_hs_div_values[i];
> + /* Calculate lowest possible value for n1 */
> + n1 = div_u64(div_u64(FDCO_MIN, hs_div), frequency);
> + if (!n1 || (n1 & 1))
> + n1++;
> + while (n1 <= 128) {
> + fdco = (u64)frequency * (u64)hs_div * (u64)n1;
> + if (fdco > FDCO_MAX)
> + break;
> + if (fdco >= FDCO_MIN && fdco < best_fdco) {
> + *out_n1 = n1;
> + *out_hs_div = hs_div;
> + *out_rfreq = div64_u64(fdco << 28, data->fxtal);
> + best_fdco = fdco;
> + }
> + n1 += (n1 == 1 ? 1 : 2);
> + }
> + }
> +
> + if (best_fdco == ULLONG_MAX)
> + return -EINVAL;
> +
> + return 0;
> +}
> +
> +static unsigned long si570_recalc_rate(struct clk_hw *hw,
> + unsigned long parent_rate)
> +{
> + int err;
> + u64 rfreq, rate;
> + unsigned int n1, hs_div;
> + struct clk_si570 *data = to_clk_si570(hw);
> +
> + err = si570_get_divs(data, &rfreq, &n1, &hs_div);
> + if (err) {
> + dev_err(&data->i2c_client->dev, "unable to recalc rate\n");
> + return data->frequency;
> + }
> +
> + rfreq = div_u64(rfreq, hs_div * n1);
> + rate = (data->fxtal * rfreq) >> 28;
> +
> + return rate;
> +}
> +
> +static long si570_round_rate(struct clk_hw *hw, unsigned long rate,
> + unsigned long *parent_rate)
> +{
> + int err;
> + u64 rfreq;
> + unsigned int n1, hs_div;
> + struct clk_si570 *data = to_clk_si570(hw);
> +
> + if (!rate)
> + return 0;
> +
> + if (div64_u64(abs(rate - data->frequency) * 10000LL,
> + data->frequency) < 35) {
> + rfreq = div64_u64((data->rfreq * rate) +
> + div64_u64(data->frequency, 2), data->frequency);
> + n1 = data->n1;
> + hs_div = data->hs_div;
> +
> + } else {
> + err = si570_calc_divs(rate, data, &rfreq, &n1, &hs_div);
> + if (err) {
> + dev_err(&data->i2c_client->dev,
> + "unable to round rate\n");
> + return 0;
> + }
> + }
> +
> + return rate;
> +}
> +
> +/**
> + * si570_set_frequency() - Adjust output frequency
> + * @data: Driver data structure
> + * @frequency: Target frequency
> + * Returns 0 on success.
> + *
> + * Update output frequency for big frequency changes (> 3,500 ppm).
> + */
> +static int si570_set_frequency(struct clk_si570 *data, unsigned long frequency)
> +{
> + int err;
> +
> + err = si570_calc_divs(frequency, data, &data->rfreq, &data->n1,
> + &data->hs_div);
> + if (err)
> + return err;
> +
> + /*
> + * The DCO reg should be accessed with a read-modify-write operation
> + * per AN334
> + */
> + regmap_write(data->regmap, SI570_REG_FREEZE_DCO, SI570_FREEZE_DCO);
> + regmap_write(data->regmap, SI570_REG_HS_N1 + data->div_offset,
> + ((data->hs_div - HS_DIV_OFFSET) << HS_DIV_SHIFT) |
> + (((data->n1 - 1) >> 2) & N1_6_2_MASK));
> + si570_update_rfreq(data);
> + regmap_write(data->regmap, SI570_REG_FREEZE_DCO, 0);
> + regmap_write(data->regmap, SI570_REG_CONTROL, SI570_CNTRL_NEWFREQ);
> +
> + /* Applying a new frequency can take up to 10ms */
> + usleep_range(10000, 12000);
> +
> + return 0;
> +}
> +
> +/**
> + * si570_set_frequency_small() - Adjust output frequency
> + * @data: Driver data structure
> + * @frequency: Target frequency
> + * Returns 0 on success.
> + *
> + * Update output frequency for small frequency changes (< 3,500 ppm).
> + */
> +static int si570_set_frequency_small(struct clk_si570 *data,
> + unsigned long frequency)
> +{
> + /*
> + * This is a re-implementation of DIV_ROUND_CLOSEST
> + * using the div64_u64 function lieu of letting the compiler
> + * insert EABI calls
> + */
> + data->rfreq = div64_u64((data->rfreq * frequency) +
> + div_u64(data->frequency, 2), data->frequency);
> + regmap_write(data->regmap, SI570_REG_CONTROL, SI570_CNTRL_FREEZE_M);
> + si570_update_rfreq(data);
> + regmap_write(data->regmap, SI570_REG_CONTROL, 0);
> +
> + /* Applying a new frequency (small change) can take up to 100us */
> + usleep_range(100, 200);
> +
> + return 0;
> +}
> +
> +static int si570_set_rate(struct clk_hw *hw, unsigned long rate,
> + unsigned long parent_rate)
> +{
> + struct clk_si570 *data = to_clk_si570(hw);
> + struct i2c_client *client = data->i2c_client;
> + int err;
> +
> + if (rate < SI570_MIN_FREQ || rate > data->max_freq) {
> + dev_err(&client->dev,
> + "requested frequency %lu Hz is out of range\n", rate);
> + return -EINVAL;
> + }
> +
> + if (div64_u64(abs(rate - data->frequency) * 10000LL,
> + data->frequency) < 35)
> + err = si570_set_frequency_small(data, rate);
> + else
> + err = si570_set_frequency(data, rate);
> +
> + if (err)
> + return err;
> +
> + data->frequency = rate;
> +
> + return 0;
> +}
> +
> +static const struct clk_ops si570_clk_ops = {
> + .recalc_rate = si570_recalc_rate,
> + .round_rate = si570_round_rate,
> + .set_rate = si570_set_rate,
> +};
> +
> +static bool si570_regmap_is_volatile(struct device *dev, unsigned int reg)
> +{
> + switch (reg) {
> + case SI570_REG_CONTROL:
> + return true;
> + default:
> + return false;
> + }
> +}
> +
> +static bool si570_regmap_is_writeable(struct device *dev, unsigned int reg)
> +{
> + switch (reg) {
> + case SI570_REG_HS_N1 ... (SI570_REG_RFREQ4 + SI570_DIV_OFFSET_7PPM):
> + case SI570_REG_CONTROL:
> + case SI570_REG_FREEZE_DCO:
> + return true;
> + default:
> + return false;
> + }
> +}
> +
> +static struct regmap_config si570_regmap_config = {
> + .reg_bits = 8,
> + .val_bits = 8,
> + .cache_type = REGCACHE_RBTREE,
> + .max_register = 137,
> + .writeable_reg = si570_regmap_is_writeable,
> + .volatile_reg = si570_regmap_is_volatile,
> +};
> +
> +static int si570_probe(struct i2c_client *client,
> + const struct i2c_device_id *id)
> +{
> + struct clk_si570 *data;
> + struct clk_init_data init;
> + struct clk *clk;
> + u32 initial_fout, factory_fout, stability;
> + int err;
> + enum clk_si570_variant variant = id->driver_data;
> +
> + data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
> + if (!data)
> + return -ENOMEM;
> +
> + init.ops = &si570_clk_ops;
> + init.flags = CLK_IS_ROOT;
> + init.num_parents = 0;
> + data->hw.init = &init;
> + data->i2c_client = client;
> +
> + if (variant == si57x) {
> + err = of_property_read_u32(client->dev.of_node,
> + "temperature-stability", &stability);
> + if (err) {
> + dev_err(&client->dev,
> + "'temperature-stability' property missing\n");
> + return err;
> + }
> + /* adjust register offsets for 7ppm devices */
> + if (stability == 7)
> + data->div_offset = SI570_DIV_OFFSET_7PPM;
> +
> + data->max_freq = SI570_MAX_FREQ;
> + } else {
> + data->max_freq = SI598_MAX_FREQ;
> + }
> +
> + if (of_property_read_string(client->dev.of_node, "clock-output-names",
> + &init.name))
> + init.name = client->dev.of_node->name;
> +
> + err = of_property_read_u32(client->dev.of_node, "factory-fout",
> + &factory_fout);
> + if (err) {
> + dev_err(&client->dev, "'factory-fout' property missing\n");
> + return err;
> + }
> +
> + data->regmap = devm_regmap_init_i2c(client, &si570_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);
> + err = si570_get_defaults(data, factory_fout);
> + if (err)
> + return err;
> +
> + clk = devm_clk_register(&client->dev, &data->hw);
> + if (IS_ERR(clk)) {
> + dev_err(&client->dev, "clock registration failed\n");
> + return PTR_ERR(clk);
> + }
> + err = of_clk_add_provider(client->dev.of_node, of_clk_src_simple_get,
> + clk);
> + if (err) {
> + dev_err(&client->dev, "unable to add clk provider\n");
> + return err;
> + }
> +
> + /* Read the requested initial output frequency from device tree */
> + if (!of_property_read_u32(client->dev.of_node, "clock-frequency",
> + &initial_fout)) {
> + err = clk_set_rate(clk, initial_fout);
> + if (err) {
> + of_clk_del_provider(client->dev.of_node);
> + return err;
> + }
> + }
> +
> + /* Display a message indicating that we've successfully registered */
> + dev_info(&client->dev, "registered, current frequency %llu Hz\n",
> + data->frequency);
> +
> + return 0;
> +}
> +
> +static int si570_remove(struct i2c_client *client)
> +{
> + of_clk_del_provider(client->dev.of_node);
> + return 0;
> +}
> +
> +static const struct i2c_device_id si570_id[] = {
> + { "si570", si57x },
> + { "si571", si57x },
> + { "si598", si59x },
> + { "si599", si59x },
> + { }
> +};
> +MODULE_DEVICE_TABLE(i2c, si570_id);
> +
> +static const struct of_device_id clk_si570_of_match[] = {
> + { .compatible = "silabs,si570" },
> + { .compatible = "silabs,si571" },
> + { .compatible = "silabs,si598" },
> + { .compatible = "silabs,si599" },
> + { },
> +};
> +MODULE_DEVICE_TABLE(of, clk_si570_of_match);
> +
> +static struct i2c_driver si570_driver = {
> + .driver = {
> + .name = "si570",
> + .of_match_table = of_match_ptr(clk_si570_of_match),
> + },
> + .probe = si570_probe,
> + .remove = si570_remove,
> + .id_table = si570_id,
> +};
> +module_i2c_driver(si570_driver);
> +
> +MODULE_AUTHOR("Guenter Roeck <[email protected]>");
> +MODULE_AUTHOR("Soeren Brinkmann <[email protected]");
> +MODULE_DESCRIPTION("Si570 driver");
> +MODULE_LICENSE("GPL");
> --
> 1.8.4
>
>
Quoting Sören Brinkmann (2013-10-02 10:20:38)
> Hi Mike,
>
> could you please comment on this/apply it to clk-next?
It looks good and is in the queue. Will show up in clk-next in a few
days.
Thanks,
Mike
>
> Thanks,
> Sören
>
> On Sat, Sep 21, 2013 at 04:40:39PM -0700, Soren Brinkmann wrote:
> > Add a driver for SILabs 570, 571, 598, 599 programmable oscillators.
> > The devices generate low-jitter clock signals and are reprogrammable via
> > an I2C interface.
> >
> > Cc: Guenter Roeck <[email protected]>
> > Signed-off-by: Soren Brinkmann <[email protected]>
> > ---
> > v5:
> > - fix typo in bindings documentation
> > - mention the unit for the 'temperature-stability' property
> > - remove calls to clk_unregister() (the device managed code takes care
> > of it)
> >
> > v4:
> > - actually check and handle error on clk_set_rate() call
> >
> > v3:
> > - add delay in the path for small frequency changes, which can take up
> > to 100us according to the data sheet
> > - use real range for usleep_range() argument
> > - use dev_err() over dev_warn() in set_rate()
> > - add list of applicable devices for 7ppm DT prop
> > - remove comments regarding platform data
> > - ignore 7ppm DT prop for incompatible devices
> > - replace raw numbers with #defines
> > - convert DT prop 'temperature-stability' from boolean to u32
> > - make 'temperature-stability' DT prop required (actually not fully
> > true, for 59x it is ignored and the driver does not require its
> > presence)
> >
> > v2:
> > - document clock-output-names in bindings documentation
> > - don't use wildcards in compatibility string
> > - change Kconfig entry to "... 570 and compatible devices"
> > - change some indentation flaws
> > - use 10000 as MIN and MAX value in usleep_range
> > - fail probe() if 'factory-fout' is not provided in DT
> > - default factory fout #defines removed
> > - use i2c driver_data instead of OF data
> > - remove some related structs and data
> > - rename DT property 'initial-fout' => 'clock-frequency' (like si5351
> > driver)
> > - add some more details regarding the 'factory-fout' DT property
> > ---
> > .../devicetree/bindings/clock/silabs,si570.txt | 39 ++
> > drivers/clk/Kconfig | 10 +
> > drivers/clk/Makefile | 1 +
> > drivers/clk/clk-si570.c | 531 +++++++++++++++++++++
> > 4 files changed, 581 insertions(+)
> > create mode 100644 Documentation/devicetree/bindings/clock/silabs,si570.txt
> > create mode 100644 drivers/clk/clk-si570.c
> >
> > diff --git a/Documentation/devicetree/bindings/clock/silabs,si570.txt b/Documentation/devicetree/bindings/clock/silabs,si570.txt
> > new file mode 100644
> > index 0000000..c09f21e
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/clock/silabs,si570.txt
> > @@ -0,0 +1,39 @@
> > +Binding for Silicon Labs 570, 571, 598 and 599 programmable
> > +I2C clock generators.
> > +
> > +Reference
> > +This binding uses the common clock binding[1]. Details about the devices can be
> > +found in the data sheets[2][3].
> > +
> > +[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
> > +[2] Si570/571 Data Sheet
> > + http://www.silabs.com/Support%20Documents/TechnicalDocs/si570.pdf
> > +[3] Si598/599 Data Sheet
> > + http://www.silabs.com/Support%20Documents/TechnicalDocs/si598-99.pdf
> > +
> > +Required properties:
> > + - compatible: Shall be one of "silabs,si570", "silabs,si571",
> > + "silabs,si598", "silabs,si599"
> > + - reg: I2C device address.
> > + - #clock-cells: From common clock bindings: Shall be 0.
> > + - factory-fout: Factory set default frequency. This frequency is part specific.
> > + The correct frequency for the part used has to be provided in
> > + order to generate the correct output frequencies. For more
> > + details, please refer to the data sheet.
> > + - temperature-stability: Temperature stability of the device in PPM. Should be
> > + one of: 7, 20, 50 or 100.
> > +
> > +Optional properties:
> > + - clock-output-names: From common clock bindings. Recommended to be "si570".
> > + - 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.
> > +
> > +Example:
> > + si570: clock-generator@5d {
> > + #clock-cells = <0>;
> > + compatible = "silabs,si570";
> > + temperature-stability = <50>;
> > + reg = <0x5d>;
> > + factory-fout = <156250000>;
> > + };
> > diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
> > index 279407a..349b88a 100644
> > --- a/drivers/clk/Kconfig
> > +++ b/drivers/clk/Kconfig
> > @@ -64,6 +64,16 @@ config COMMON_CLK_SI5351
> > This driver supports Silicon Labs 5351A/B/C programmable clock
> > generators.
> >
> > +config COMMON_CLK_SI570
> > + tristate "Clock driver for SiLabs 570 and compatible devices"
> > + depends on I2C
> > + depends on OF
> > + select REGMAP_I2C
> > + help
> > + ---help---
> > + This driver supports Silicon Labs 570/571/598/599 programmable
> > + clock generators.
> > +
> > config COMMON_CLK_S2MPS11
> > tristate "Clock driver for S2MPS11 MFD"
> > depends on MFD_SEC_CORE
> > diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
> > index 7b11106..c0e94b3 100644
> > --- a/drivers/clk/Makefile
> > +++ b/drivers/clk/Makefile
> > @@ -40,6 +40,7 @@ obj-$(CONFIG_COMMON_CLK_AXI_CLKGEN) += clk-axi-clkgen.o
> > obj-$(CONFIG_COMMON_CLK_WM831X) += clk-wm831x.o
> > obj-$(CONFIG_COMMON_CLK_MAX77686) += clk-max77686.o
> > obj-$(CONFIG_COMMON_CLK_SI5351) += clk-si5351.o
> > +obj-$(CONFIG_COMMON_CLK_SI570) += clk-si570.o
> > obj-$(CONFIG_COMMON_CLK_S2MPS11) += clk-s2mps11.o
> > obj-$(CONFIG_CLK_TWL6040) += clk-twl6040.o
> > obj-$(CONFIG_CLK_PPC_CORENET) += clk-ppc-corenet.o
> > diff --git a/drivers/clk/clk-si570.c b/drivers/clk/clk-si570.c
> > new file mode 100644
> > index 0000000..5d0ac9f
> > --- /dev/null
> > +++ b/drivers/clk/clk-si570.c
> > @@ -0,0 +1,531 @@
> > +/*
> > + * Driver for Silicon Labs Si570/Si571 Programmable XO/VCXO
> > + *
> > + * Copyright (C) 2010, 2011 Ericsson AB.
> > + * Copyright (C) 2011 Guenter Roeck.
> > + * Copyright (C) 2011 - 2013 Xilinx Inc.
> > + *
> > + * Author: Guenter Roeck <[email protected]>
> > + * Sören Brinkmann <[email protected]>
> > + *
> > + * 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; either version 2 of the License, or
> > + * (at your option) any later version.
> > + *
> > + * 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.
> > + */
> > +
> > +#include <linux/clk-provider.h>
> > +#include <linux/delay.h>
> > +#include <linux/module.h>
> > +#include <linux/i2c.h>
> > +#include <linux/regmap.h>
> > +#include <linux/slab.h>
> > +
> > +/* Si570 registers */
> > +#define SI570_REG_HS_N1 7
> > +#define SI570_REG_N1_RFREQ0 8
> > +#define SI570_REG_RFREQ1 9
> > +#define SI570_REG_RFREQ2 10
> > +#define SI570_REG_RFREQ3 11
> > +#define SI570_REG_RFREQ4 12
> > +#define SI570_REG_CONTROL 135
> > +#define SI570_REG_FREEZE_DCO 137
> > +#define SI570_DIV_OFFSET_7PPM 6
> > +
> > +#define HS_DIV_SHIFT 5
> > +#define HS_DIV_MASK 0xe0
> > +#define HS_DIV_OFFSET 4
> > +#define N1_6_2_MASK 0x1f
> > +#define N1_1_0_MASK 0xc0
> > +#define RFREQ_37_32_MASK 0x3f
> > +
> > +#define SI570_MIN_FREQ 10000000L
> > +#define SI570_MAX_FREQ 1417500000L
> > +#define SI598_MAX_FREQ 525000000L
> > +
> > +#define FDCO_MIN 4850000000LL
> > +#define FDCO_MAX 5670000000LL
> > +
> > +#define SI570_CNTRL_RECALL (1 << 0)
> > +#define SI570_CNTRL_FREEZE_M (1 << 5)
> > +#define SI570_CNTRL_NEWFREQ (1 << 6)
> > +
> > +#define SI570_FREEZE_DCO (1 << 4)
> > +
> > +/**
> > + * struct clk_si570:
> > + * @hw: Clock hw struct
> > + * @regmap: Device's regmap
> > + * @div_offset: Rgister offset for dividers
> > + * @max_freq: Maximum frequency for this device
> > + * @fxtal: Factory xtal frequency
> > + * @n1: Clock divider N1
> > + * @hs_div: Clock divider HSDIV
> > + * @rfreq: Clock multiplier RFREQ
> > + * @frequency: Current output frequency
> > + * @i2c_client: I2C client pointer
> > + */
> > +struct clk_si570 {
> > + struct clk_hw hw;
> > + struct regmap *regmap;
> > + unsigned int div_offset;
> > + u64 max_freq;
> > + u64 fxtal;
> > + unsigned int n1;
> > + unsigned int hs_div;
> > + u64 rfreq;
> > + u64 frequency;
> > + struct i2c_client *i2c_client;
> > +};
> > +#define to_clk_si570(_hw) container_of(_hw, struct clk_si570, hw)
> > +
> > +enum clk_si570_variant {
> > + si57x,
> > + si59x
> > +};
> > +
> > +/**
> > + * si570_get_divs() - Read clock dividers from HW
> > + * @data: Pointer to struct clk_si570
> > + * @rfreq: Fractional multiplier (output)
> > + * @n1: Divider N1 (output)
> > + * @hs_div: Divider HSDIV (output)
> > + * Returns 0 on success, negative errno otherwise.
> > + *
> > + * Retrieve clock dividers and multipliers from the HW.
> > + */
> > +static int si570_get_divs(struct clk_si570 *data, u64 *rfreq,
> > + unsigned int *n1, unsigned int *hs_div)
> > +{
> > + int err;
> > + u8 reg[6];
> > + u64 tmp;
> > +
> > + err = regmap_bulk_read(data->regmap, SI570_REG_HS_N1 + data->div_offset,
> > + reg, ARRAY_SIZE(reg));
> > + if (err)
> > + return err;
> > +
> > + *hs_div = ((reg[0] & HS_DIV_MASK) >> HS_DIV_SHIFT) + HS_DIV_OFFSET;
> > + *n1 = ((reg[0] & N1_6_2_MASK) << 2) + ((reg[1] & N1_1_0_MASK) >> 6) + 1;
> > + /* Handle invalid cases */
> > + if (*n1 > 1)
> > + *n1 &= ~1;
> > +
> > + tmp = reg[1] & RFREQ_37_32_MASK;
> > + tmp = (tmp << 8) + reg[2];
> > + tmp = (tmp << 8) + reg[3];
> > + tmp = (tmp << 8) + reg[4];
> > + tmp = (tmp << 8) + reg[5];
> > + *rfreq = tmp;
> > +
> > + return 0;
> > +}
> > +
> > +/**
> > + * si570_get_defaults() - Get default values
> > + * @data: Driver data structure
> > + * @fout: Factory frequency output
> > + * Returns 0 on success, negative errno otherwise.
> > + */
> > +static int si570_get_defaults(struct clk_si570 *data, u64 fout)
> > +{
> > + int err;
> > + u64 fdco;
> > +
> > + regmap_write(data->regmap, SI570_REG_CONTROL, SI570_CNTRL_RECALL);
> > +
> > + err = si570_get_divs(data, &data->rfreq, &data->n1, &data->hs_div);
> > + if (err)
> > + return err;
> > +
> > + /*
> > + * Accept optional precision loss to avoid arithmetic overflows.
> > + * Acceptable per Silicon Labs Application Note AN334.
> > + */
> > + fdco = fout * data->n1 * data->hs_div;
> > + if (fdco >= (1LL << 36))
> > + data->fxtal = div64_u64(fdco << 24, data->rfreq >> 4);
> > + else
> > + data->fxtal = div64_u64(fdco << 28, data->rfreq);
> > +
> > + data->frequency = fout;
> > +
> > + return 0;
> > +}
> > +
> > +/**
> > + * si570_update_rfreq() - Update clock multiplier
> > + * @data: Driver data structure
> > + * Passes on regmap_bulk_write() return value.
> > + */
> > +static int si570_update_rfreq(struct clk_si570 *data)
> > +{
> > + u8 reg[5];
> > +
> > + reg[0] = ((data->n1 - 1) << 6) |
> > + ((data->rfreq >> 32) & RFREQ_37_32_MASK);
> > + reg[1] = (data->rfreq >> 24) & 0xff;
> > + reg[2] = (data->rfreq >> 16) & 0xff;
> > + reg[3] = (data->rfreq >> 8) & 0xff;
> > + reg[4] = data->rfreq & 0xff;
> > +
> > + return regmap_bulk_write(data->regmap, SI570_REG_N1_RFREQ0 +
> > + data->div_offset, reg, ARRAY_SIZE(reg));
> > +}
> > +
> > +/**
> > + * si570_calc_divs() - Caluclate clock dividers
> > + * @frequency: Target frequency
> > + * @data: Driver data structure
> > + * @out_rfreq: RFREG fractional multiplier (output)
> > + * @out_n1: Clock divider N1 (output)
> > + * @out_hs_div: Clock divider HSDIV (output)
> > + * Returns 0 on success, negative errno otherwise.
> > + *
> > + * Calculate the clock dividers (@out_hs_div, @out_n1) and clock multiplier
> > + * (@out_rfreq) for a given target @frequency.
> > + */
> > +static int si570_calc_divs(unsigned long frequency, struct clk_si570 *data,
> > + u64 *out_rfreq, unsigned int *out_n1, unsigned int *out_hs_div)
> > +{
> > + int i;
> > + unsigned int n1, hs_div;
> > + u64 fdco, best_fdco = ULLONG_MAX;
> > + static const uint8_t si570_hs_div_values[] = { 11, 9, 7, 6, 5, 4 };
> > +
> > + for (i = 0; i < ARRAY_SIZE(si570_hs_div_values); i++) {
> > + hs_div = si570_hs_div_values[i];
> > + /* Calculate lowest possible value for n1 */
> > + n1 = div_u64(div_u64(FDCO_MIN, hs_div), frequency);
> > + if (!n1 || (n1 & 1))
> > + n1++;
> > + while (n1 <= 128) {
> > + fdco = (u64)frequency * (u64)hs_div * (u64)n1;
> > + if (fdco > FDCO_MAX)
> > + break;
> > + if (fdco >= FDCO_MIN && fdco < best_fdco) {
> > + *out_n1 = n1;
> > + *out_hs_div = hs_div;
> > + *out_rfreq = div64_u64(fdco << 28, data->fxtal);
> > + best_fdco = fdco;
> > + }
> > + n1 += (n1 == 1 ? 1 : 2);
> > + }
> > + }
> > +
> > + if (best_fdco == ULLONG_MAX)
> > + return -EINVAL;
> > +
> > + return 0;
> > +}
> > +
> > +static unsigned long si570_recalc_rate(struct clk_hw *hw,
> > + unsigned long parent_rate)
> > +{
> > + int err;
> > + u64 rfreq, rate;
> > + unsigned int n1, hs_div;
> > + struct clk_si570 *data = to_clk_si570(hw);
> > +
> > + err = si570_get_divs(data, &rfreq, &n1, &hs_div);
> > + if (err) {
> > + dev_err(&data->i2c_client->dev, "unable to recalc rate\n");
> > + return data->frequency;
> > + }
> > +
> > + rfreq = div_u64(rfreq, hs_div * n1);
> > + rate = (data->fxtal * rfreq) >> 28;
> > +
> > + return rate;
> > +}
> > +
> > +static long si570_round_rate(struct clk_hw *hw, unsigned long rate,
> > + unsigned long *parent_rate)
> > +{
> > + int err;
> > + u64 rfreq;
> > + unsigned int n1, hs_div;
> > + struct clk_si570 *data = to_clk_si570(hw);
> > +
> > + if (!rate)
> > + return 0;
> > +
> > + if (div64_u64(abs(rate - data->frequency) * 10000LL,
> > + data->frequency) < 35) {
> > + rfreq = div64_u64((data->rfreq * rate) +
> > + div64_u64(data->frequency, 2), data->frequency);
> > + n1 = data->n1;
> > + hs_div = data->hs_div;
> > +
> > + } else {
> > + err = si570_calc_divs(rate, data, &rfreq, &n1, &hs_div);
> > + if (err) {
> > + dev_err(&data->i2c_client->dev,
> > + "unable to round rate\n");
> > + return 0;
> > + }
> > + }
> > +
> > + return rate;
> > +}
> > +
> > +/**
> > + * si570_set_frequency() - Adjust output frequency
> > + * @data: Driver data structure
> > + * @frequency: Target frequency
> > + * Returns 0 on success.
> > + *
> > + * Update output frequency for big frequency changes (> 3,500 ppm).
> > + */
> > +static int si570_set_frequency(struct clk_si570 *data, unsigned long frequency)
> > +{
> > + int err;
> > +
> > + err = si570_calc_divs(frequency, data, &data->rfreq, &data->n1,
> > + &data->hs_div);
> > + if (err)
> > + return err;
> > +
> > + /*
> > + * The DCO reg should be accessed with a read-modify-write operation
> > + * per AN334
> > + */
> > + regmap_write(data->regmap, SI570_REG_FREEZE_DCO, SI570_FREEZE_DCO);
> > + regmap_write(data->regmap, SI570_REG_HS_N1 + data->div_offset,
> > + ((data->hs_div - HS_DIV_OFFSET) << HS_DIV_SHIFT) |
> > + (((data->n1 - 1) >> 2) & N1_6_2_MASK));
> > + si570_update_rfreq(data);
> > + regmap_write(data->regmap, SI570_REG_FREEZE_DCO, 0);
> > + regmap_write(data->regmap, SI570_REG_CONTROL, SI570_CNTRL_NEWFREQ);
> > +
> > + /* Applying a new frequency can take up to 10ms */
> > + usleep_range(10000, 12000);
> > +
> > + return 0;
> > +}
> > +
> > +/**
> > + * si570_set_frequency_small() - Adjust output frequency
> > + * @data: Driver data structure
> > + * @frequency: Target frequency
> > + * Returns 0 on success.
> > + *
> > + * Update output frequency for small frequency changes (< 3,500 ppm).
> > + */
> > +static int si570_set_frequency_small(struct clk_si570 *data,
> > + unsigned long frequency)
> > +{
> > + /*
> > + * This is a re-implementation of DIV_ROUND_CLOSEST
> > + * using the div64_u64 function lieu of letting the compiler
> > + * insert EABI calls
> > + */
> > + data->rfreq = div64_u64((data->rfreq * frequency) +
> > + div_u64(data->frequency, 2), data->frequency);
> > + regmap_write(data->regmap, SI570_REG_CONTROL, SI570_CNTRL_FREEZE_M);
> > + si570_update_rfreq(data);
> > + regmap_write(data->regmap, SI570_REG_CONTROL, 0);
> > +
> > + /* Applying a new frequency (small change) can take up to 100us */
> > + usleep_range(100, 200);
> > +
> > + return 0;
> > +}
> > +
> > +static int si570_set_rate(struct clk_hw *hw, unsigned long rate,
> > + unsigned long parent_rate)
> > +{
> > + struct clk_si570 *data = to_clk_si570(hw);
> > + struct i2c_client *client = data->i2c_client;
> > + int err;
> > +
> > + if (rate < SI570_MIN_FREQ || rate > data->max_freq) {
> > + dev_err(&client->dev,
> > + "requested frequency %lu Hz is out of range\n", rate);
> > + return -EINVAL;
> > + }
> > +
> > + if (div64_u64(abs(rate - data->frequency) * 10000LL,
> > + data->frequency) < 35)
> > + err = si570_set_frequency_small(data, rate);
> > + else
> > + err = si570_set_frequency(data, rate);
> > +
> > + if (err)
> > + return err;
> > +
> > + data->frequency = rate;
> > +
> > + return 0;
> > +}
> > +
> > +static const struct clk_ops si570_clk_ops = {
> > + .recalc_rate = si570_recalc_rate,
> > + .round_rate = si570_round_rate,
> > + .set_rate = si570_set_rate,
> > +};
> > +
> > +static bool si570_regmap_is_volatile(struct device *dev, unsigned int reg)
> > +{
> > + switch (reg) {
> > + case SI570_REG_CONTROL:
> > + return true;
> > + default:
> > + return false;
> > + }
> > +}
> > +
> > +static bool si570_regmap_is_writeable(struct device *dev, unsigned int reg)
> > +{
> > + switch (reg) {
> > + case SI570_REG_HS_N1 ... (SI570_REG_RFREQ4 + SI570_DIV_OFFSET_7PPM):
> > + case SI570_REG_CONTROL:
> > + case SI570_REG_FREEZE_DCO:
> > + return true;
> > + default:
> > + return false;
> > + }
> > +}
> > +
> > +static struct regmap_config si570_regmap_config = {
> > + .reg_bits = 8,
> > + .val_bits = 8,
> > + .cache_type = REGCACHE_RBTREE,
> > + .max_register = 137,
> > + .writeable_reg = si570_regmap_is_writeable,
> > + .volatile_reg = si570_regmap_is_volatile,
> > +};
> > +
> > +static int si570_probe(struct i2c_client *client,
> > + const struct i2c_device_id *id)
> > +{
> > + struct clk_si570 *data;
> > + struct clk_init_data init;
> > + struct clk *clk;
> > + u32 initial_fout, factory_fout, stability;
> > + int err;
> > + enum clk_si570_variant variant = id->driver_data;
> > +
> > + data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
> > + if (!data)
> > + return -ENOMEM;
> > +
> > + init.ops = &si570_clk_ops;
> > + init.flags = CLK_IS_ROOT;
> > + init.num_parents = 0;
> > + data->hw.init = &init;
> > + data->i2c_client = client;
> > +
> > + if (variant == si57x) {
> > + err = of_property_read_u32(client->dev.of_node,
> > + "temperature-stability", &stability);
> > + if (err) {
> > + dev_err(&client->dev,
> > + "'temperature-stability' property missing\n");
> > + return err;
> > + }
> > + /* adjust register offsets for 7ppm devices */
> > + if (stability == 7)
> > + data->div_offset = SI570_DIV_OFFSET_7PPM;
> > +
> > + data->max_freq = SI570_MAX_FREQ;
> > + } else {
> > + data->max_freq = SI598_MAX_FREQ;
> > + }
> > +
> > + if (of_property_read_string(client->dev.of_node, "clock-output-names",
> > + &init.name))
> > + init.name = client->dev.of_node->name;
> > +
> > + err = of_property_read_u32(client->dev.of_node, "factory-fout",
> > + &factory_fout);
> > + if (err) {
> > + dev_err(&client->dev, "'factory-fout' property missing\n");
> > + return err;
> > + }
> > +
> > + data->regmap = devm_regmap_init_i2c(client, &si570_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);
> > + err = si570_get_defaults(data, factory_fout);
> > + if (err)
> > + return err;
> > +
> > + clk = devm_clk_register(&client->dev, &data->hw);
> > + if (IS_ERR(clk)) {
> > + dev_err(&client->dev, "clock registration failed\n");
> > + return PTR_ERR(clk);
> > + }
> > + err = of_clk_add_provider(client->dev.of_node, of_clk_src_simple_get,
> > + clk);
> > + if (err) {
> > + dev_err(&client->dev, "unable to add clk provider\n");
> > + return err;
> > + }
> > +
> > + /* Read the requested initial output frequency from device tree */
> > + if (!of_property_read_u32(client->dev.of_node, "clock-frequency",
> > + &initial_fout)) {
> > + err = clk_set_rate(clk, initial_fout);
> > + if (err) {
> > + of_clk_del_provider(client->dev.of_node);
> > + return err;
> > + }
> > + }
> > +
> > + /* Display a message indicating that we've successfully registered */
> > + dev_info(&client->dev, "registered, current frequency %llu Hz\n",
> > + data->frequency);
> > +
> > + return 0;
> > +}
> > +
> > +static int si570_remove(struct i2c_client *client)
> > +{
> > + of_clk_del_provider(client->dev.of_node);
> > + return 0;
> > +}
> > +
> > +static const struct i2c_device_id si570_id[] = {
> > + { "si570", si57x },
> > + { "si571", si57x },
> > + { "si598", si59x },
> > + { "si599", si59x },
> > + { }
> > +};
> > +MODULE_DEVICE_TABLE(i2c, si570_id);
> > +
> > +static const struct of_device_id clk_si570_of_match[] = {
> > + { .compatible = "silabs,si570" },
> > + { .compatible = "silabs,si571" },
> > + { .compatible = "silabs,si598" },
> > + { .compatible = "silabs,si599" },
> > + { },
> > +};
> > +MODULE_DEVICE_TABLE(of, clk_si570_of_match);
> > +
> > +static struct i2c_driver si570_driver = {
> > + .driver = {
> > + .name = "si570",
> > + .of_match_table = of_match_ptr(clk_si570_of_match),
> > + },
> > + .probe = si570_probe,
> > + .remove = si570_remove,
> > + .id_table = si570_id,
> > +};
> > +module_i2c_driver(si570_driver);
> > +
> > +MODULE_AUTHOR("Guenter Roeck <[email protected]>");
> > +MODULE_AUTHOR("Soeren Brinkmann <[email protected]");
> > +MODULE_DESCRIPTION("Si570 driver");
> > +MODULE_LICENSE("GPL");
> > --
> > 1.8.4
> >
> >
On Wed, Oct 02, 2013 at 04:17:51PM -0700, Mike Turquette wrote:
> Quoting Sören Brinkmann (2013-10-02 10:20:38)
> > Hi Mike,
> >
> > could you please comment on this/apply it to clk-next?
>
> It looks good and is in the queue. Will show up in clk-next in a few
> days.
Thanks, Mike.
Sören