From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753638Ab3JBXSA (ORCPT ); Wed, 2 Oct 2013 19:18:00 -0400 Received: from mail-pa0-f52.google.com ([209.85.220.52]:51839 "EHLO mail-pa0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752940Ab3JBXR6 convert rfc822-to-8bit (ORCPT ); Wed, 2 Oct 2013 19:17:58 -0400 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8BIT To: =?utf-8?q?S=C3=B6ren_Brinkmann?= , Rob Herring , Pawel Moll , Mark Rutland , Stephen Warren , Ian Campbell , Rob Landley , Grant Likely , Guenter Roeck , Sebastian Hesselbarth , Joe Perches From: Mike Turquette In-Reply-To: Cc: , , , , Hyun Kwon References: <1379806839-13762-1-git-send-email-soren.brinkmann@xilinx.com> Message-ID: <20131002231751.4343.81234@quantum> User-Agent: alot/0.3.4 Subject: Re: [PATCH v5] clk: si570: Add a driver for SI570 oscillators Date: Wed, 02 Oct 2013 16:17:51 -0700 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 > > Signed-off-by: Soren Brinkmann > > --- > > 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 > > + * Sören Brinkmann > > + * > > + * 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 > > +#include > > +#include > > +#include > > +#include > > +#include > > + > > +/* 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 "); > > +MODULE_AUTHOR("Soeren Brinkmann > +MODULE_DESCRIPTION("Si570 driver"); > > +MODULE_LICENSE("GPL"); > > -- > > 1.8.4 > > > > From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Turquette Subject: Re: [PATCH v5] clk: si570: Add a driver for SI570 oscillators Date: Wed, 02 Oct 2013 16:17:51 -0700 Message-ID: <20131002231751.4343.81234@quantum> References: <1379806839-13762-1-git-send-email-soren.brinkmann@xilinx.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: =?utf-8?q?S=C3=B6ren_Brinkmann?= , Rob Herring , Pawel Moll , Mark Rutland , Stephen Warren , Ian Campbell , Rob Landley , Grant Likely , Guenter Roeck , Sebastian Hesselbarth , Joe Perches Cc: devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-doc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, Hyun Kwon List-Id: devicetree@vger.kernel.org Quoting S=C3=B6ren Brinkmann (2013-10-02 10:20:38) > Hi Mike, >=20 > 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 >=20 > Thanks, > S=C3=B6ren >=20 > On Sat, Sep 21, 2013 at 04:40:39PM -0700, Soren Brinkmann wrote: > > Add a driver for SILabs 570, 571, 598, 599 programmable oscillators= =2E > > The devices generate low-jitter clock signals and are reprogrammabl= e via > > an I2C interface. > >=20 > > Cc: Guenter Roeck > > Signed-off-by: Soren Brinkmann > > --- > > 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) > >=20 > > v4: > > - actually check and handle error on clk_set_rate() call > >=20 > > v3: > > - add delay in the path for small frequency changes, which can tak= e 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 full= y > > true, for 59x it is ignored and the driver does not require its > > presence) > >=20 > > 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' =3D> 'clock-frequency' (like s= i5351 > > 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 > >=20 > > diff --git a/Documentation/devicetree/bindings/clock/silabs,si570.t= xt 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 d= evices 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 pr= ovided in > > + order to generate the correct output frequencies. Fo= r more > > + details, please refer to the data sheet. > > + - temperature-stability: Temperature stability of the device in P= PM. 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 =3D <0>; > > + compatible =3D "silabs,si570"; > > + temperature-stability =3D <50>; > > + reg =3D <0x5d>; > > + factory-fout =3D <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 cl= ock > > generators. > > =20 > > +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 programma= ble > > + 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-$(CONFIG_COMMON_CLK_AXI_CLKGEN) +=3D clk-axi-= clkgen.o > > obj-$(CONFIG_COMMON_CLK_WM831X) +=3D clk-wm831x.o > > obj-$(CONFIG_COMMON_CLK_MAX77686) +=3D clk-max77686.o > > obj-$(CONFIG_COMMON_CLK_SI5351) +=3D clk-si5351.o > > +obj-$(CONFIG_COMMON_CLK_SI570) +=3D clk-si570.o > > obj-$(CONFIG_COMMON_CLK_S2MPS11) +=3D clk-s2mps11.o > > obj-$(CONFIG_CLK_TWL6040) +=3D clk-twl6040.o > > obj-$(CONFIG_CLK_PPC_CORENET) +=3D 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 > > + * S=C3=B6ren Brinkmann > > + * > > + * This program is free software; you can redistribute it and/or m= odify > > + * it under the terms of the GNU General Public License as publish= ed 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 > > +#include > > +#include > > +#include > > +#include > > +#include > > + > > +/* 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, h= w) > > + > > +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 =3D regmap_bulk_read(data->regmap, SI570_REG_HS_N1 + data= ->div_offset, > > + reg, ARRAY_SIZE(reg)); > > + if (err) > > + return err; > > + > > + *hs_div =3D ((reg[0] & HS_DIV_MASK) >> HS_DIV_SHIFT) + HS_DIV= _OFFSET; > > + *n1 =3D ((reg[0] & N1_6_2_MASK) << 2) + ((reg[1] & N1_1_0_MAS= K) >> 6) + 1; > > + /* Handle invalid cases */ > > + if (*n1 > 1) > > + *n1 &=3D ~1; > > + > > + tmp =3D reg[1] & RFREQ_37_32_MASK; > > + tmp =3D (tmp << 8) + reg[2]; > > + tmp =3D (tmp << 8) + reg[3]; > > + tmp =3D (tmp << 8) + reg[4]; > > + tmp =3D (tmp << 8) + reg[5]; > > + *rfreq =3D 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_REC= ALL); > > + > > + err =3D si570_get_divs(data, &data->rfreq, &data->n1, &data->= hs_div); > > + if (err) > > + return err; > > + > > + /* > > + * Accept optional precision loss to avoid arithmetic overflo= ws. > > + * Acceptable per Silicon Labs Application Note AN334. > > + */ > > + fdco =3D fout * data->n1 * data->hs_div; > > + if (fdco >=3D (1LL << 36)) > > + data->fxtal =3D div64_u64(fdco << 24, data->rfreq >> = 4); > > + else > > + data->fxtal =3D div64_u64(fdco << 28, data->rfreq); > > + > > + data->frequency =3D 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] =3D ((data->n1 - 1) << 6) | > > + ((data->rfreq >> 32) & RFREQ_37_32_MASK); > > + reg[1] =3D (data->rfreq >> 24) & 0xff; > > + reg[2] =3D (data->rfreq >> 16) & 0xff; > > + reg[3] =3D (data->rfreq >> 8) & 0xff; > > + reg[4] =3D 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 m= ultiplier > > + * (@out_rfreq) for a given target @frequency. > > + */ > > +static int si570_calc_divs(unsigned long frequency, struct clk_si5= 70 *data, > > + u64 *out_rfreq, unsigned int *out_n1, unsigned int *o= ut_hs_div) > > +{ > > + int i; > > + unsigned int n1, hs_div; > > + u64 fdco, best_fdco =3D ULLONG_MAX; > > + static const uint8_t si570_hs_div_values[] =3D { 11, 9, 7, 6,= 5, 4 }; > > + > > + for (i =3D 0; i < ARRAY_SIZE(si570_hs_div_values); i++) { > > + hs_div =3D si570_hs_div_values[i]; > > + /* Calculate lowest possible value for n1 */ > > + n1 =3D div_u64(div_u64(FDCO_MIN, hs_div), frequency); > > + if (!n1 || (n1 & 1)) > > + n1++; > > + while (n1 <=3D 128) { > > + fdco =3D (u64)frequency * (u64)hs_div * (u64)= n1; > > + if (fdco > FDCO_MAX) > > + break; > > + if (fdco >=3D FDCO_MIN && fdco < best_fdco) { > > + *out_n1 =3D n1; > > + *out_hs_div =3D hs_div; > > + *out_rfreq =3D div64_u64(fdco << 28, = data->fxtal); > > + best_fdco =3D fdco; > > + } > > + n1 +=3D (n1 =3D=3D 1 ? 1 : 2); > > + } > > + } > > + > > + if (best_fdco =3D=3D 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 =3D to_clk_si570(hw); > > + > > + err =3D si570_get_divs(data, &rfreq, &n1, &hs_div); > > + if (err) { > > + dev_err(&data->i2c_client->dev, "unable to recalc rat= e\n"); > > + return data->frequency; > > + } > > + > > + rfreq =3D div_u64(rfreq, hs_div * n1); > > + rate =3D (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 =3D to_clk_si570(hw); > > + > > + if (!rate) > > + return 0; > > + > > + if (div64_u64(abs(rate - data->frequency) * 10000LL, > > + data->frequency) < 35) { > > + rfreq =3D div64_u64((data->rfreq * rate) + > > + div64_u64(data->frequency, 2), data->= frequency); > > + n1 =3D data->n1; > > + hs_div =3D data->hs_div; > > + > > + } else { > > + err =3D 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)= =2E > > + */ > > +static int si570_set_frequency(struct clk_si570 *data, unsigned lo= ng frequency) > > +{ > > + int err; > > + > > + err =3D 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 op= eration > > + * 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_SHI= =46T) | > > + (((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_NEW= =46REQ); > > + > > + /* 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 pp= m). > > + */ > > +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 =3D div64_u64((data->rfreq * frequency) + > > + div_u64(data->frequency, 2), data->frequency)= ; > > + regmap_write(data->regmap, SI570_REG_CONTROL, SI570_CNTRL_FRE= EZE_M); > > + si570_update_rfreq(data); > > + regmap_write(data->regmap, SI570_REG_CONTROL, 0); > > + > > + /* Applying a new frequency (small change) can take up to 100= us */ > > + 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 =3D to_clk_si570(hw); > > + struct i2c_client *client =3D 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 =3D si570_set_frequency_small(data, rate); > > + else > > + err =3D si570_set_frequency(data, rate); > > + > > + if (err) > > + return err; > > + > > + data->frequency =3D rate; > > + > > + return 0; > > +} > > + > > +static const struct clk_ops si570_clk_ops =3D { > > + .recalc_rate =3D si570_recalc_rate, > > + .round_rate =3D si570_round_rate, > > + .set_rate =3D 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 =3D { > > + .reg_bits =3D 8, > > + .val_bits =3D 8, > > + .cache_type =3D REGCACHE_RBTREE, > > + .max_register =3D 137, > > + .writeable_reg =3D si570_regmap_is_writeable, > > + .volatile_reg =3D 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 =3D id->driver_data; > > + > > + data =3D devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL= ); > > + if (!data) > > + return -ENOMEM; > > + > > + init.ops =3D &si570_clk_ops; > > + init.flags =3D CLK_IS_ROOT; > > + init.num_parents =3D 0; > > + data->hw.init =3D &init; > > + data->i2c_client =3D client; > > + > > + if (variant =3D=3D si57x) { > > + err =3D of_property_read_u32(client->dev.of_node, > > + "temperature-stability", &stability); > > + if (err) { > > + dev_err(&client->dev, > > + "'temperature-stability' property m= issing\n"); > > + return err; > > + } > > + /* adjust register offsets for 7ppm devices */ > > + if (stability =3D=3D 7) > > + data->div_offset =3D SI570_DIV_OFFSET_7PPM; > > + > > + data->max_freq =3D SI570_MAX_FREQ; > > + } else { > > + data->max_freq =3D SI598_MAX_FREQ; > > + } > > + > > + if (of_property_read_string(client->dev.of_node, "clock-outpu= t-names", > > + &init.name)) > > + init.name =3D client->dev.of_node->name; > > + > > + err =3D of_property_read_u32(client->dev.of_node, "factory-fo= ut", > > + &factory_fout); > > + if (err) { > > + dev_err(&client->dev, "'factory-fout' property missin= g\n"); > > + return err; > > + } > > + > > + data->regmap =3D devm_regmap_init_i2c(client, &si570_regmap_c= onfig); > > + if (IS_ERR(data->regmap)) { > > + dev_err(&client->dev, "failed to allocate register ma= p\n"); > > + return PTR_ERR(data->regmap); > > + } > > + > > + i2c_set_clientdata(client, data); > > + err =3D si570_get_defaults(data, factory_fout); > > + if (err) > > + return err; > > + > > + clk =3D devm_clk_register(&client->dev, &data->hw); > > + if (IS_ERR(clk)) { > > + dev_err(&client->dev, "clock registration failed\n"); > > + return PTR_ERR(clk); > > + } > > + err =3D of_clk_add_provider(client->dev.of_node, of_clk_src_s= imple_get, > > + clk); > > + if (err) { > > + dev_err(&client->dev, "unable to add clk provider\n")= ; > > + return err; > > + } > > + > > + /* Read the requested initial output frequency from device tr= ee */ > > + if (!of_property_read_u32(client->dev.of_node, "clock-frequen= cy", > > + &initial_fout)) { > > + err =3D 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 regis= tered */ > > + 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[] =3D { > > + { "si570", si57x }, > > + { "si571", si57x }, > > + { "si598", si59x }, > > + { "si599", si59x }, > > + { } > > +}; > > +MODULE_DEVICE_TABLE(i2c, si570_id); > > + > > +static const struct of_device_id clk_si570_of_match[] =3D { > > + { .compatible =3D "silabs,si570" }, > > + { .compatible =3D "silabs,si571" }, > > + { .compatible =3D "silabs,si598" }, > > + { .compatible =3D "silabs,si599" }, > > + { }, > > +}; > > +MODULE_DEVICE_TABLE(of, clk_si570_of_match); > > + > > +static struct i2c_driver si570_driver =3D { > > + .driver =3D { > > + .name =3D "si570", > > + .of_match_table =3D of_match_ptr(clk_si570_of_match), > > + }, > > + .probe =3D si570_probe, > > + .remove =3D si570_remove, > > + .id_table =3D si570_id, > > +}; > > +module_i2c_driver(si570_driver); > > + > > +MODULE_AUTHOR("Guenter Roeck "); > > +MODULE_AUTHOR("Soeren Brinkmann > +MODULE_DESCRIPTION("Si570 driver"); > > +MODULE_LICENSE("GPL"); > > --=20 > > 1.8.4 > >=20 > > -- To unsubscribe from this list: send the line "unsubscribe devicetree" i= n the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html From mboxrd@z Thu Jan 1 00:00:00 1970 From: mturquette@linaro.org (Mike Turquette) Date: Wed, 02 Oct 2013 16:17:51 -0700 Subject: [PATCH v5] clk: si570: Add a driver for SI570 oscillators In-Reply-To: References: <1379806839-13762-1-git-send-email-soren.brinkmann@xilinx.com> Message-ID: <20131002231751.4343.81234@quantum> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Quoting S?ren 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, > S?ren > > 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 > > Signed-off-by: Soren Brinkmann > > --- > > 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 at 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 > > + * S?ren Brinkmann > > + * > > + * 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 > > +#include > > +#include > > +#include > > +#include > > +#include > > + > > +/* 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 "); > > +MODULE_AUTHOR("Soeren Brinkmann > +MODULE_DESCRIPTION("Si570 driver"); > > +MODULE_LICENSE("GPL"); > > -- > > 1.8.4 > > > >