--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for Silicon Labs Si5341/Si5340 Clock generator
+ * Copyright (C) 2019 Topic Embedded Products
+ * Author: Mike Looijmans <mike.looijmans@topic.nl>
+ */
+
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/delay.h>
+#include <linux/gcd.h>
+#include <linux/math64.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <asm/unaligned.h>
+
+#define SI5341_MAX_NUM_OUTPUTS 10
+#define SI5340_MAX_NUM_OUTPUTS 4
+
+#define SI5341_NUM_SYNTH 5
+#define SI5340_NUM_SYNTH 4
+
+/* Range of the synthesizer fractional divider */
+#define SI5341_SYNTH_N_MIN 10
+#define SI5341_SYNTH_N_MAX 4095
+
+/* The chip can get its input clock from 3 input pins or an XTAL */
+
+/* There is one PLL running at 13500–14256 MHz */
+#define SI5341_PLL_VCO_MIN 13500000000ull
+#define SI5341_PLL_VCO_MAX 14256000000ull
+
+/* The 5 frequency synthesizers obtain their input from the PLL */
+struct clk_si5341_synth {
+ struct clk_hw hw;
+ struct clk_si5341 *data;
+ u8 index;
+};
+#define to_clk_si5341_synth(_hw) \
+ container_of(_hw, struct clk_si5341_synth, hw)
+
+/* The output stages can be connected to any synth (full mux) */
+struct clk_si5341_output {
+ struct clk_hw hw;
+ struct clk_si5341 *data;
+ u8 index;
+};
+#define to_clk_si5341_output(_hw) \
+ container_of(_hw, struct clk_si5341_output, hw)
+
+struct clk_si5341 {
+ struct clk_hw hw;
+ struct regmap *regmap;
+ struct i2c_client *i2c_client;
+ struct clk_si5341_synth synth[SI5341_NUM_SYNTH];
+ struct clk_si5341_output clk[SI5341_MAX_NUM_OUTPUTS];
+ struct clk *pxtal;
+ const char *pxtal_name;
+ const u16 *reg_output_offset;
+ const u16 *reg_rdiv_offset;
+ u64 freq_vco; /* 13500–14256 MHz */
+ u8 num_outputs;
+ u8 num_synth;
+};
+#define to_clk_si5341(_hw) container_of(_hw, struct clk_si5341, hw)
+
+struct clk_si5341_output_config {
+ u8 out_format_drv_bits;
+ u8 out_cm_ampl_bits;
+ bool synth_master;
+ bool always_on;
+};
+
+#define SI5341_PAGE 0x0001
+#define SI5341_PN_BASE 0x0002
+#define SI5341_DEVICE_REV 0x0005
+#define SI5341_STATUS 0x000C
+#define SI5341_SOFT_RST 0x001C
+
+/* Input dividers (48-bit) */
+#define SI5341_IN_PDIV(x) (0x0208 + ((x) * 10))
+#define SI5341_IN_PSET(x) (0x020E + ((x) * 10))
+
+/* PLL configuration */
+#define SI5341_PLL_M_NUM 0x0235
+#define SI5341_PLL_M_DEN 0x023B
+
+/* Output configuration */
+#define SI5341_OUT_CONFIG(output) \
+ ((output)->data->reg_output_offset[(output)->index])
+#define SI5341_OUT_FORMAT(output) (SI5341_OUT_CONFIG(output) + 1)
+#define SI5341_OUT_CM(output) (SI5341_OUT_CONFIG(output) + 2)
+#define SI5341_OUT_MUX_SEL(output) (SI5341_OUT_CONFIG(output) + 3)
+#define SI5341_OUT_R_REG(output) \
+ ((output)->data->reg_rdiv_offset[(output)->index])
+
+/* Synthesize N divider */
+#define SI5341_SYNTH_N_NUM(x) (0x0302 + ((x) * 11))
+#define SI5341_SYNTH_N_DEN(x) (0x0308 + ((x) * 11))
+#define SI5341_SYNTH_N_UPD(x) (0x030C + ((x) * 11))
+
+/* Synthesizer output enable, phase bypass, power mode */
+#define SI5341_SYNTH_N_CLK_TO_OUTX_EN 0x0A03
+#define SI5341_SYNTH_N_PIBYP 0x0A04
+#define SI5341_SYNTH_N_PDNB 0x0A05
+#define SI5341_SYNTH_N_CLK_DIS 0x0B4A
+
+#define SI5341_REGISTER_MAX 0xBFF
+
+/* SI5341_OUT_CONFIG bits */
+#define SI5341_OUT_CFG_PDN BIT(0)
+#define SI5341_OUT_CFG_OE BIT(1)
+#define SI5341_OUT_CFG_RDIV_FORCE2 BIT(2)
+
+/* Static configuration (to be moved to firmware) */
+struct si5341_reg_default {
+ u16 address;
+ u8 value;
+};
+
+/* Output configuration registers 0..9 are not quite logically organized */
+static const u16 si5341_reg_output_offset[] = {
+ 0x0108,
+ 0x010D,
+ 0x0112,
+ 0x0117,
+ 0x011C,
+ 0x0121,
+ 0x0126,
+ 0x012B,
+ 0x0130,
+ 0x013A,
+};
+
+static const u16 si5340_reg_output_offset[] = {
+ 0x0112,
+ 0x0117,
+ 0x0126,
+ 0x012B,
+};
+
+/* The location of the R divider registers */
+static const u16 si5341_reg_rdiv_offset[] = {
+ 0x024A,
+ 0x024D,
+ 0x0250,
+ 0x0253,
+ 0x0256,
+ 0x0259,
+ 0x025C,
+ 0x025F,
+ 0x0262,
+ 0x0268,
+};
+static const u16 si5340_reg_rdiv_offset[] = {
+ 0x0250,
+ 0x0253,
+ 0x025C,
+ 0x025F,
+};
+
+/*
+ * Programming sequence from ClockBuilder, settings to initialize the system
+ * using only the XTAL input, without pre-divider.
+ * This also contains settings that aren't mentioned anywhere in the datasheet.
+ * The "known" settings like synth and output configuration are done later.
+ */
+static const struct si5341_reg_default si5341_reg_defaults[] = {
+ { 0x0017, 0x3A }, /* INT mask (disable interrupts) */
+ { 0x0018, 0xFF }, /* INT mask */
+ { 0x0021, 0x0F }, /* Select XTAL as input */
+ { 0x0022, 0x00 }, /* Not in datasheet */
+ { 0x002B, 0x02 }, /* SPI config */
+ { 0x002C, 0x20 }, /* LOS enable for XTAL */
+ { 0x002D, 0x00 }, /* LOS timing */
+ { 0x002E, 0x00 },
+ { 0x002F, 0x00 },
+ { 0x0030, 0x00 },
+ { 0x0031, 0x00 },
+ { 0x0032, 0x00 },
+ { 0x0033, 0x00 },
+ { 0x0034, 0x00 },
+ { 0x0035, 0x00 },
+ { 0x0036, 0x00 },
+ { 0x0037, 0x00 },
+ { 0x0038, 0x00 }, /* LOS setting (thresholds) */
+ { 0x0039, 0x00 },
+ { 0x003A, 0x00 },
+ { 0x003B, 0x00 },
+ { 0x003C, 0x00 },
+ { 0x003D, 0x00 }, /* LOS setting (thresholds) end */
+ { 0x0041, 0x00 }, /* LOS0_DIV_SEL */
+ { 0x0042, 0x00 }, /* LOS1_DIV_SEL */
+ { 0x0043, 0x00 }, /* LOS2_DIV_SEL */
+ { 0x0044, 0x00 }, /* LOS3_DIV_SEL */
+ { 0x009E, 0x00 }, /* Not in datasheet */
+ { 0x0102, 0x01 }, /* Enable outputs */
+ { 0x013F, 0x00 }, /* Not in datasheet */
+ { 0x0140, 0x00 }, /* Not in datasheet */
+ { 0x0141, 0x40 }, /* OUT LOS */
+ { 0x0202, 0x00 }, /* XAXB_FREQ_OFFSET (=0)*/
+ { 0x0203, 0x00 },
+ { 0x0204, 0x00 },
+ { 0x0205, 0x00 },
+ { 0x0206, 0x00 }, /* PXAXB (2^x) */
+ { 0x0208, 0x00 }, /* Px divider setting (usually 0) */
+ { 0x0209, 0x00 },
+ { 0x020A, 0x00 },
+ { 0x020B, 0x00 },
+ { 0x020C, 0x00 },
+ { 0x020D, 0x00 },
+ { 0x020E, 0x00 },
+ { 0x020F, 0x00 },
+ { 0x0210, 0x00 },
+ { 0x0211, 0x00 },
+ { 0x0212, 0x00 },
+ { 0x0213, 0x00 },
+ { 0x0214, 0x00 },
+ { 0x0215, 0x00 },
+ { 0x0216, 0x00 },
+ { 0x0217, 0x00 },
+ { 0x0218, 0x00 },
+ { 0x0219, 0x00 },
+ { 0x021A, 0x00 },
+ { 0x021B, 0x00 },
+ { 0x021C, 0x00 },
+ { 0x021D, 0x00 },
+ { 0x021E, 0x00 },
+ { 0x021F, 0x00 },
+ { 0x0220, 0x00 },
+ { 0x0221, 0x00 },
+ { 0x0222, 0x00 },
+ { 0x0223, 0x00 },
+ { 0x0224, 0x00 },
+ { 0x0225, 0x00 },
+ { 0x0226, 0x00 },
+ { 0x0227, 0x00 },
+ { 0x0228, 0x00 },
+ { 0x0229, 0x00 },
+ { 0x022A, 0x00 },
+ { 0x022B, 0x00 },
+ { 0x022C, 0x00 },
+ { 0x022D, 0x00 },
+ { 0x022E, 0x00 },
+ { 0x022F, 0x00 }, /* Px divider setting (usually 0) end */
+ { 0x026B, 0x00 }, /* DESIGN_ID (ASCII string) */
+ { 0x026C, 0x00 },
+ { 0x026D, 0x00 },
+ { 0x026E, 0x00 },
+ { 0x026F, 0x00 },
+ { 0x0270, 0x00 },
+ { 0x0271, 0x00 },
+ { 0x0272, 0x00 }, /* DESIGN_ID (ASCII string) end */
+ { 0x0339, 0x1F }, /* N_FSTEP_MSK */
+ { 0x033B, 0x00 }, /* Nx_FSTEPW (Frequency step) */
+ { 0x033C, 0x00 },
+ { 0x033D, 0x00 },
+ { 0x033E, 0x00 },
+ { 0x033F, 0x00 },
+ { 0x0340, 0x00 },
+ { 0x0341, 0x00 },
+ { 0x0342, 0x00 },
+ { 0x0343, 0x00 },
+ { 0x0344, 0x00 },
+ { 0x0345, 0x00 },
+ { 0x0346, 0x00 },
+ { 0x0347, 0x00 },
+ { 0x0348, 0x00 },
+ { 0x0349, 0x00 },
+ { 0x034A, 0x00 },
+ { 0x034B, 0x00 },
+ { 0x034C, 0x00 },
+ { 0x034D, 0x00 },
+ { 0x034E, 0x00 },
+ { 0x034F, 0x00 },
+ { 0x0350, 0x00 },
+ { 0x0351, 0x00 },
+ { 0x0352, 0x00 },
+ { 0x0353, 0x00 },
+ { 0x0354, 0x00 },
+ { 0x0355, 0x00 },
+ { 0x0356, 0x00 },
+ { 0x0357, 0x00 },
+ { 0x0358, 0x00 }, /* Nx_FSTEPW (Frequency step) end */
+ { 0x0359, 0x00 }, /* Nx_DELAY */
+ { 0x035A, 0x00 },
+ { 0x035B, 0x00 },
+ { 0x035C, 0x00 },
+ { 0x035D, 0x00 },
+ { 0x035E, 0x00 },
+ { 0x035F, 0x00 },
+ { 0x0360, 0x00 },
+ { 0x0361, 0x00 },
+ { 0x0362, 0x00 }, /* Nx_DELAY end */
+ { 0x0802, 0x00 }, /* Not in datasheet */
+ { 0x0803, 0x00 }, /* Not in datasheet */
+ { 0x0804, 0x00 }, /* Not in datasheet */
+ { 0x090E, 0x02 }, /* XAXB_EXTCLK_EN=0 XAXB_PDNB=1 (use XTAL) */
+ { 0x091C, 0x04 }, /* ZDM_EN=4 (Normal mode) */
+ { 0x0943, 0x00 }, /* IO_VDD_SEL=0 (0=1v8, use 1=3v3) */
+ { 0x0949, 0x00 }, /* IN_EN (disable input clocks) */
+ { 0x094A, 0x00 }, /* INx_TO_PFD_EN (disabled) */
+ { 0x0A02, 0x00 }, /* Not in datasheet */
+ { 0x0B44, 0x0F }, /* PDIV_ENB (datasheet does not mention what it is) */
+};
+
+/* Read and interpret a 44-bit followed by a 32-bit value in the regmap */
+static int si5341_decode_44_32(struct regmap *regmap, unsigned int reg,
+ u64 *val1, u32 *val2)
+{
+ int err;
+ u8 r[10];
+
+ err = regmap_bulk_read(regmap, reg, r, 10);
+ if (err < 0)
+ return err;
+
+ *val1 = ((u64)((r[5] & 0x0f) << 8 | r[4]) << 32) |
+ (get_unaligned_le32(r));
+ *val2 = get_unaligned_le32(&r[6]);
+
+ return 0;
+}
+
+static int si5341_encode_44_32(struct regmap *regmap, unsigned int reg,
+ u64 n_num, u32 n_den)
+{
+ u8 r[10];
+
+ /* Shift left as far as possible without overflowing */
+ while (!(n_num & BIT_ULL(43)) && !(n_den & BIT(31))) {
+ n_num <<= 1;
+ n_den <<= 1;
+ }
+
+ /* 44 bits (6 bytes) numerator */
+ put_unaligned_le32(n_num, r);
+ r[4] = (n_num >> 32) & 0xff;
+ r[5] = (n_num >> 40) & 0x0f;
+ /* 32 bits denominator */
+ put_unaligned_le32(n_den, &r[6]);
+
+ /* Program the fraction */
+ return regmap_bulk_write(regmap, reg, r, sizeof(r));
+}
+
+/* VCO, we assume it runs at a constant frequency */
+static unsigned long si5341_clk_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct clk_si5341 *data = to_clk_si5341(hw);
+ int err;
+ u64 res;
+ u64 m_num;
+ u32 m_den;
+ unsigned int shift;
+
+ /* Assume that PDIV is not being used, just read the PLL setting */
+ err = si5341_decode_44_32(data->regmap, SI5341_PLL_M_NUM,
+ &m_num, &m_den);
+ if (err < 0)
+ return 0;
+
+ if (!m_num || !m_den)
+ return 0;
+
+ /*
+ * Though m_num is 64-bit, only the upper bits are actually used. While
+ * calculating m_num and m_den, they are shifted as far as possible to
+ * the left. To avoid 96-bit division here, we just shift them back so
+ * we can do with just 64 bits.
+ */
+ shift = 0;
+ res = m_num;
+ while (res & 0xffff00000000ULL) {
+ ++shift;
+ res >>= 1;
+ }
+ res *= parent_rate;
+ do_div(res, (m_den >> shift));
+
+ /* We cannot return the actual frequency in 32 bit, store it locally */
+ data->freq_vco = res;
+
+ /* Report kHz since the value is out of range */
+ do_div(res, 1000);
+
+ return (unsigned long)res;
+}
+
+static const struct clk_ops si5341_clk_ops = {
+ .recalc_rate = si5341_clk_recalc_rate,
+};
+
+/* Synthesizers, there are 5 synthesizers that connect to any of the outputs */
+
+/* The synthesizer is on if all power and enable bits are set */
+static int si5341_synth_clk_is_on(struct clk_hw *hw)
+{
+ struct clk_si5341_synth *synth = to_clk_si5341_synth(hw);
+ int err;
+ u32 val;
+ u8 index = synth->index;
+
+ err = regmap_read(synth->data->regmap,
+ SI5341_SYNTH_N_CLK_TO_OUTX_EN, &val);
+ if (err < 0)
+ return 0;
+
+ if (!(val & BIT(index)))
+ return 0;
+
+ err = regmap_read(synth->data->regmap, SI5341_SYNTH_N_PDNB, &val);
+ if (err < 0)
+ return 0;
+
+ if (!(val & BIT(index)))
+ return 0;
+
+ /* This bit must be 0 for the synthesizer to receive clock input */
+ err = regmap_read(synth->data->regmap, SI5341_SYNTH_N_CLK_DIS, &val);
+ if (err < 0)
+ return 0;
+
+ return !(val & BIT(index));
+}
+
+static void si5341_synth_clk_unprepare(struct clk_hw *hw)
+{
+ struct clk_si5341_synth *synth = to_clk_si5341_synth(hw);
+ u8 index = synth->index; /* In range 0..5 */
+ u8 mask = BIT(index);
+
+ /* Disable output */
+ regmap_update_bits(synth->data->regmap,
+ SI5341_SYNTH_N_CLK_TO_OUTX_EN, mask, 0);
+ /* Power down */
+ regmap_update_bits(synth->data->regmap,
+ SI5341_SYNTH_N_PDNB, mask, 0);
+ /* Disable clock input to synth (set to 1 to disable) */
+ regmap_update_bits(synth->data->regmap,
+ SI5341_SYNTH_N_CLK_DIS, mask, mask);
+}
+
+static int si5341_synth_clk_prepare(struct clk_hw *hw)
+{
+ struct clk_si5341_synth *synth = to_clk_si5341_synth(hw);
+ int err;
+ u8 index = synth->index;
+ u8 mask = BIT(index);
+
+ /* Power up */
+ err = regmap_update_bits(synth->data->regmap,
+ SI5341_SYNTH_N_PDNB, mask, mask);
+ if (err < 0)
+ return err;
+
+ /* Enable clock input to synth (set bit to 0 to enable) */
+ err = regmap_update_bits(synth->data->regmap,
+ SI5341_SYNTH_N_CLK_DIS, mask, 0);
+ if (err < 0)
+ return err;
+
+ /* Enable output */
+ return regmap_update_bits(synth->data->regmap,
+ SI5341_SYNTH_N_CLK_TO_OUTX_EN, mask, mask);
+}
+
+/* Synth clock frequency: Fvco * n_den / n_den, with Fvco in 13500-14256 MHz */
+static unsigned long si5341_synth_clk_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct clk_si5341_synth *synth = to_clk_si5341_synth(hw);
+ u64 f;
+ u64 n_num;
+ u32 n_den;
+ int err;
+
+ err = si5341_decode_44_32(synth->data->regmap,
+ SI5341_SYNTH_N_NUM(synth->index), &n_num, &n_den);
+ if (err < 0)
+ return err;
+
+ /*
+ * n_num and n_den are shifted left as much as possible, so to prevent
+ * overflow in 64-bit math, we shift n_den 4 bits to the right
+ */
+ f = synth->data->freq_vco;
+ f *= n_den >> 4;
+
+ /* Now we need to to 64-bit division: f/n_num */
+ /* And compensate for the 4 bits we dropped */
+ f = div64_u64(f, (n_num >> 4));
+
+ return f;
+}
+
+static long si5341_synth_clk_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *parent_rate)
+{
+ struct clk_si5341_synth *synth = to_clk_si5341_synth(hw);
+ u64 f;
+
+ /* The synthesizer accuracy is such that anything in range will work */
+ f = synth->data->freq_vco;
+ do_div(f, SI5341_SYNTH_N_MAX);
+ if (rate < f)
+ return f;
+
+ f = synth->data->freq_vco;
+ do_div(f, SI5341_SYNTH_N_MIN);
+ if (rate > f)
+ return f;
+
+ return rate;
+}
+
+static int si5341_synth_program(struct clk_si5341_synth *synth,
+ u64 n_num, u32 n_den, bool is_integer)
+{
+ int err;
+ u8 index = synth->index;
+
+ err = si5341_encode_44_32(synth->data->regmap,
+ SI5341_SYNTH_N_NUM(index), n_num, n_den);
+
+ err = regmap_update_bits(synth->data->regmap,
+ SI5341_SYNTH_N_PIBYP, BIT(index), is_integer ? BIT(index) : 0);
+ if (err < 0)
+ return err;
+
+ return regmap_write(synth->data->regmap,
+ SI5341_SYNTH_N_UPD(index), 0x01);
+}
+
+
+static int si5341_synth_clk_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct clk_si5341_synth *synth = to_clk_si5341_synth(hw);
+ u64 n_num;
+ u32 n_den;
+ u32 r;
+ u32 g;
+ bool is_integer;
+
+ n_num = synth->data->freq_vco;
+ n_den = rate;
+
+ /* see if there's an integer solution */
+ r = do_div(n_num, rate);
+ is_integer = (r == 0);
+ if (is_integer) {
+ /* Integer divider equal to n_num */
+ n_den = 1;
+ } else {
+ /* Calculate a fractional solution */
+ g = gcd(r, rate);
+ n_den = rate / g;
+ n_num *= n_den;
+ n_num += r / g;
+ }
+
+ dev_dbg(&synth->data->i2c_client->dev,
+ "%s(%u): n=0x%llx d=0x%x %s\n", __func__,
+ synth->index, n_num, n_den,
+ is_integer ? "int" : "frac");
+
+ return si5341_synth_program(synth, n_num, n_den, is_integer);
+}
+
+static const struct clk_ops si5341_synth_clk_ops = {
+ .is_prepared = si5341_synth_clk_is_on,
+ .prepare = si5341_synth_clk_prepare,
+ .unprepare = si5341_synth_clk_unprepare,
+ .recalc_rate = si5341_synth_clk_recalc_rate,
+ .round_rate = si5341_synth_clk_round_rate,
+ .set_rate = si5341_synth_clk_set_rate,
+};
+
+static int si5341_output_clk_is_on(struct clk_hw *hw)
+{
+ struct clk_si5341_output *output = to_clk_si5341_output(hw);
+ int err;
+ u32 val;
+
+ err = regmap_read(output->data->regmap,
+ SI5341_OUT_CONFIG(output), &val);
+ if (err < 0)
+ return err;
+
+ /* Bit 0=PDN, 1=OE so only a value of 0x2 enables the output */
+ return (val & 0x03) == SI5341_OUT_CFG_OE;
+}
+
+/* Disables and then powers down the output */
+static void si5341_output_clk_unprepare(struct clk_hw *hw)
+{
+ struct clk_si5341_output *output = to_clk_si5341_output(hw);
+
+ regmap_update_bits(output->data->regmap,
+ SI5341_OUT_CONFIG(output),
+ SI5341_OUT_CFG_OE, 0);
+ regmap_update_bits(output->data->regmap,
+ SI5341_OUT_CONFIG(output),
+ SI5341_OUT_CFG_PDN, SI5341_OUT_CFG_PDN);
+}
+
+/* Powers up and then enables the output */
+static int si5341_output_clk_prepare(struct clk_hw *hw)
+{
+ struct clk_si5341_output *output = to_clk_si5341_output(hw);
+ int err;
+
+ err = regmap_update_bits(output->data->regmap,
+ SI5341_OUT_CONFIG(output),
+ SI5341_OUT_CFG_PDN, 0);
+ if (err < 0)
+ return err;
+
+ return regmap_update_bits(output->data->regmap,
+ SI5341_OUT_CONFIG(output),
+ SI5341_OUT_CFG_OE, SI5341_OUT_CFG_OE);
+}
+
+static unsigned long si5341_output_clk_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct clk_si5341_output *output = to_clk_si5341_output(hw);
+ int err;
+ u32 val;
+ u32 r_divider;
+ u8 r[3];
+
+ err = regmap_bulk_read(output->data->regmap,
+ SI5341_OUT_R_REG(output), r, 3);
+ if (err < 0)
+ return err;
+
+ /* Calculate value as 24-bit integer*/
+ r_divider = r[2] << 16 | r[1] << 8 | r[0];
+
+ /* If Rx_REG is zero, the divider is disabled, so return a "0" rate */
+ if (!r_divider)
+ return 0;
+
+ /* Divider is 2*(Rx_REG+1) */
+ r_divider += 1;
+ r_divider <<= 1;
+
+ err = regmap_read(output->data->regmap,
+ SI5341_OUT_CONFIG(output), &val);
+ if (err < 0)
+ return err;
+
+ if (val & SI5341_OUT_CFG_RDIV_FORCE2)
+ r_divider = 2;
+
+ return parent_rate / r_divider;
+}
+
+static long si5341_output_clk_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *parent_rate)
+{
+ unsigned long r;
+
+ r = *parent_rate >> 1;
+
+ /* If rate is an even divisor, no changes to parent required */
+ if (r && !(r % rate))
+ return (long)rate;
+
+ if (clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT) {
+ if (rate > 200000000) {
+ /* minimum r-divider is 2 */
+ r = 2;
+ } else {
+ /* Take a parent frequency near 400 MHz */
+ r = (400000000u / rate) & ~1;
+ }
+ *parent_rate = r * rate;
+ } else {
+ /* We cannot change our parent's rate, report what we can do */
+ r /= rate;
+ rate = *parent_rate / (r << 1);
+ }
+
+ return rate;
+}
+
+static int si5341_output_clk_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct clk_si5341_output *output = to_clk_si5341_output(hw);
+ /* Frequency divider is (r_div + 1) * 2 */
+ u32 r_div = (parent_rate / rate) >> 1;
+ int err;
+ u8 r[3];
+
+ if (r_div <= 1)
+ r_div = 0;
+ else if (r_div >= BIT(24))
+ r_div = BIT(24) - 1;
+ else
+ --r_div;
+
+ /* For a value of "2", we set the "OUT0_RDIV_FORCE2" bit */
+ err = regmap_update_bits(output->data->regmap,
+ SI5341_OUT_CONFIG(output),
+ SI5341_OUT_CFG_RDIV_FORCE2,
+ (r_div == 0) ? SI5341_OUT_CFG_RDIV_FORCE2 : 0);
+ if (err < 0)
+ return err;
+
+ /* Always write Rx_REG, because a zero value disables the divider */
+ r[0] = r_div ? (r_div & 0xff) : 1;
+ r[1] = (r_div >> 8) & 0xff;
+ r[2] = (r_div >> 16) & 0xff;
+ err = regmap_bulk_write(output->data->regmap,
+ SI5341_OUT_R_REG(output), r, 3);
+
+ return 0;
+}
+
+static int si5341_output_reparent(struct clk_si5341_output *output, u8 index)
+{
+ return regmap_update_bits(output->data->regmap,
+ SI5341_OUT_MUX_SEL(output), 0x07, index);
+}
+
+static int si5341_output_set_parent(struct clk_hw *hw, u8 index)
+{
+ struct clk_si5341_output *output = to_clk_si5341_output(hw);
+
+ if (index >= output->data->num_synth)
+ return -EINVAL;
+
+ return si5341_output_reparent(output, index);
+}
+
+static u8 si5341_output_get_parent(struct clk_hw *hw)
+{
+ struct clk_si5341_output *output = to_clk_si5341_output(hw);
+ int err;
+ u32 val;
+
+ err = regmap_read(output->data->regmap,
+ SI5341_OUT_MUX_SEL(output), &val);
+
+ return val & 0x7;
+}
+
+static const struct clk_ops si5341_output_clk_ops = {
+ .is_prepared = si5341_output_clk_is_on,
+ .prepare = si5341_output_clk_prepare,
+ .unprepare = si5341_output_clk_unprepare,
+ .recalc_rate = si5341_output_clk_recalc_rate,
+ .round_rate = si5341_output_clk_round_rate,
+ .set_rate = si5341_output_clk_set_rate,
+ .set_parent = si5341_output_set_parent,
+ .get_parent = si5341_output_get_parent,
+};
+
+/*
+ * The chip can be bought in a pre-programmed version, or one can program the
+ * NVM in the chip to boot up in a preset mode. This routine tries to determine
+ * if that's the case, or if we need to reset and program everything from
+ * scratch. Returns negative error, or true/false.
+ */
+static int si5341_is_programmed_already(struct clk_si5341 *data)
+{
+ int err;
+ u8 r[4];
+
+ /* Read the PLL divider value, it must have a non-zero value */
+ err = regmap_bulk_read(data->regmap, SI5341_PLL_M_DEN,
+ r, ARRAY_SIZE(r));
+ if (err < 0)
+ return err;
+
+ return !!get_unaligned_le32(r);
+}
+
+static struct clk_hw *
+of_clk_si5341_get(struct of_phandle_args *clkspec, void *_data)
+{
+ struct clk_si5341 *data = _data;
+ unsigned int idx = clkspec->args[1];
+ unsigned int group = clkspec->args[0];
+
+ switch (group) {
+ case 0:
+ if (idx >= data->num_outputs) {
+ dev_err(&data->i2c_client->dev,
+ "invalid output index %u\n", idx);
+ return ERR_PTR(-EINVAL);
+ }
+ return &data->clk[idx].hw;
+ case 1:
+ if (idx >= data->num_synth) {
+ dev_err(&data->i2c_client->dev,
+ "invalid synthesizer index %u\n", idx);
+ return ERR_PTR(-EINVAL);
+ }
+ return &data->synth[idx].hw;
+ case 2:
+ if (idx > 0) {
+ dev_err(&data->i2c_client->dev,
+ "invalid PLL index %u\n", idx);
+ return ERR_PTR(-EINVAL);
+ }
+ return &data->hw;
+ default:
+ dev_err(&data->i2c_client->dev, "invalid group %u\n", group);
+ return ERR_PTR(-EINVAL);
+ }
+}
+
+static int si5341_probe_chip_id(struct clk_si5341 *data)
+{
+ int err;
+ u8 reg[4];
+ u16 model;
+
+ err = regmap_bulk_read(data->regmap, SI5341_PN_BASE, reg,
+ ARRAY_SIZE(reg));
+ if (err < 0) {
+ dev_err(&data->i2c_client->dev, "Failed to read chip ID\n");
+ return err;
+ }
+
+ model = get_unaligned_le16(reg);
+
+ dev_info(&data->i2c_client->dev, "Chip: %x Grade: %u Rev: %u\n",
+ model, reg[2], reg[3]);
+
+ switch (model) {
+ case 0x5340:
+ data->num_outputs = SI5340_MAX_NUM_OUTPUTS;
+ data->num_synth = SI5340_NUM_SYNTH;
+ data->reg_output_offset = si5340_reg_output_offset;
+ data->reg_rdiv_offset = si5340_reg_rdiv_offset;
+ break;
+ case 0x5341:
+ data->num_outputs = SI5341_MAX_NUM_OUTPUTS;
+ data->num_synth = SI5341_NUM_SYNTH;
+ data->reg_output_offset = si5341_reg_output_offset;
+ data->reg_rdiv_offset = si5341_reg_rdiv_offset;
+ break;
+ default:
+ dev_err(&data->i2c_client->dev, "Model '%x' not supported\n",
+ model);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+/* Read active settings into the regmap cache for later reference */
+static int si5341_read_settings(struct clk_si5341 *data)
+{
+ int err;
+ u8 i;
+ u8 r[10];
+
+ err = regmap_bulk_read(data->regmap, SI5341_PLL_M_NUM, r, 10);
+ if (err < 0)
+ return err;
+
+ err = regmap_bulk_read(data->regmap,
+ SI5341_SYNTH_N_CLK_TO_OUTX_EN, r, 3);
+ if (err < 0)
+ return err;
+
+ err = regmap_bulk_read(data->regmap,
+ SI5341_SYNTH_N_CLK_DIS, r, 1);
+ if (err < 0)
+ return err;
+
+ for (i = 0; i < data->num_synth; ++i) {
+ err = regmap_bulk_read(data->regmap,
+ SI5341_SYNTH_N_NUM(i), r, 10);
+ if (err < 0)
+ return err;
+ }
+
+ for (i = 0; i < data->num_outputs; ++i) {
+ err = regmap_bulk_read(data->regmap,
+ data->reg_output_offset[i], r, 4);
+ if (err < 0)
+ return err;
+
+ err = regmap_bulk_read(data->regmap,
+ data->reg_rdiv_offset[i], r, 3);
+ if (err < 0)
+ return err;
+ }
+
+ return 0;
+}
+
+static int si5341_write_multiple(struct clk_si5341 *data,
+ const struct si5341_reg_default *values, unsigned int num_values)
+{
+ unsigned int i;
+ int res;
+
+ for (i = 0; i < num_values; ++i) {
+ res = regmap_write(data->regmap,
+ values[i].address, values[i].value);
+ if (res < 0) {
+ dev_err(&data->i2c_client->dev,
+ "Failed to write %#x:%#x\n",
+ values[i].address, values[i].value);
+ return res;
+ }
+ }
+
+ return 0;
+}
+
+static const struct si5341_reg_default si5341_preamble[] = {
+ { 0x0B25, 0x00 },
+ { 0x0502, 0x01 },
+ { 0x0505, 0x03 },
+ { 0x0957, 0x1F },
+ { 0x0B4E, 0x1A },
+};
+
+static int si5341_send_preamble(struct clk_si5341 *data)
+{
+ int res;
+ u32 revision;
+
+ /* For revision 2 and up, the values are slightly different */
+ res = regmap_read(data->regmap, SI5341_DEVICE_REV, &revision);
+ if (res < 0)
+ return res;
+
+ /* Write "preamble" as specified by datasheet */
+ res = regmap_write(data->regmap, 0xB24, revision < 2 ? 0xD8 : 0xC0);
+ if (res < 0)
+ return res;
+ res = si5341_write_multiple(data,
+ si5341_preamble, ARRAY_SIZE(si5341_preamble));
+ if (res < 0)
+ return res;
+
+ /* Datasheet specifies a 300ms wait after sending the preamble */
+ msleep(300);
+
+ return 0;
+}
+
+/* Perform a soft reset and write post-amble */
+static int si5341_finalize_defaults(struct clk_si5341 *data)
+{
+ int res;
+ u32 revision;
+
+ res = regmap_read(data->regmap, SI5341_DEVICE_REV, &revision);
+ if (res < 0)
+ return res;
+
+ dev_dbg(&data->i2c_client->dev, "%s rev=%u\n", __func__, revision);
+
+ res = regmap_write(data->regmap, SI5341_SOFT_RST, 0x01);
+ if (res < 0)
+ return res;
+
+ /* Datasheet does not explain these nameless registers */
+ res = regmap_write(data->regmap, 0xB24, revision < 2 ? 0xDB : 0xC3);
+ if (res < 0)
+ return res;
+ res = regmap_write(data->regmap, 0x0B25, 0x02);
+ if (res < 0)
+ return res;
+
+ return 0;
+}
+
+
+static const struct regmap_range si5341_regmap_volatile_range[] = {
+ regmap_reg_range(0x000C, 0x0012), /* Status */
+ regmap_reg_range(0x001C, 0x001E), /* reset, finc/fdec */
+ regmap_reg_range(0x00E2, 0x00FE), /* NVM, interrupts, device ready */
+ /* Update bits for synth config */
+ regmap_reg_range(SI5341_SYNTH_N_UPD(0), SI5341_SYNTH_N_UPD(0)),
+ regmap_reg_range(SI5341_SYNTH_N_UPD(1), SI5341_SYNTH_N_UPD(1)),
+ regmap_reg_range(SI5341_SYNTH_N_UPD(2), SI5341_SYNTH_N_UPD(2)),
+ regmap_reg_range(SI5341_SYNTH_N_UPD(3), SI5341_SYNTH_N_UPD(3)),
+ regmap_reg_range(SI5341_SYNTH_N_UPD(4), SI5341_SYNTH_N_UPD(4)),
+};
+
+static const struct regmap_access_table si5341_regmap_volatile = {
+ .yes_ranges = si5341_regmap_volatile_range,
+ .n_yes_ranges = ARRAY_SIZE(si5341_regmap_volatile_range),
+};
+
+/* Pages 0, 1, 2, 3, 9, A, B are valid, so there are 12 pages */
+static const struct regmap_range_cfg si5341_regmap_ranges[] = {
+ {
+ .range_min = 0,
+ .range_max = SI5341_REGISTER_MAX,
+ .selector_reg = SI5341_PAGE,
+ .selector_mask = 0xff,
+ .selector_shift = 0,
+ .window_start = 0,
+ .window_len = 256,
+ },
+};
+
+static const struct regmap_config si5341_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .cache_type = REGCACHE_RBTREE,
+ .ranges = si5341_regmap_ranges,
+ .num_ranges = ARRAY_SIZE(si5341_regmap_ranges),
+ .max_register = SI5341_REGISTER_MAX,
+ .volatile_table = &si5341_regmap_volatile,
+};
+
+static int si5341_dt_parse_dt(struct i2c_client *client,
+ struct clk_si5341_output_config *config)
+{
+ struct device_node *child;
+ struct device_node *np = client->dev.of_node;
+ u32 num;
+ u32 val;
+
+ memset(config, 0, sizeof(struct clk_si5341_output_config) *
+ SI5341_MAX_NUM_OUTPUTS);
+
+ for_each_child_of_node(np, child) {
+ if (of_property_read_u32(child, "reg", &num)) {
+ dev_err(&client->dev, "missing reg property of %s\n",
+ child->name);
+ goto put_child;
+ }
+
+ if (num >= SI5341_MAX_NUM_OUTPUTS) {
+ dev_err(&client->dev, "invalid clkout %d\n", num);
+ goto put_child;
+ }
+
+ if (!of_property_read_u32(child, "silabs,format", &val)) {
+ /* Set cm and ampl conservatively to 3v3 settings */
+ switch (val) {
+ case 1: /* normal differential */
+ config[num].out_cm_ampl_bits = 0x33;
+ break;
+ case 2: /* low-power differential */
+ config[num].out_cm_ampl_bits = 0x13;
+ break;
+ case 4: /* LVCMOS */
+ config[num].out_cm_ampl_bits = 0x33;
+ /* Set SI recommended impedance for LVCMOS */
+ config[num].out_format_drv_bits |= 0xc0;
+ break;
+ default:
+ dev_err(&client->dev,
+ "invalid silabs,format %u for %u\n",
+ val, num);
+ goto put_child;
+ }
+ config[num].out_format_drv_bits &= ~0x07;
+ config[num].out_format_drv_bits |= val & 0x07;
+ /* Always enable the SYNC feature */
+ config[num].out_format_drv_bits |= 0x08;
+ }
+
+ if (!of_property_read_u32(child, "silabs,common-mode", &val)) {
+ if (val > 0xf) {
+ dev_err(&client->dev,
+ "invalid silabs,common-mode %u\n",
+ val);
+ goto put_child;
+ }
+ config[num].out_cm_ampl_bits &= 0xf0;
+ config[num].out_cm_ampl_bits |= val & 0x0f;
+ }
+
+ if (!of_property_read_u32(child, "silabs,amplitude", &val)) {
+ if (val > 0xf) {
+ dev_err(&client->dev,
+ "invalid silabs,amplitude %u\n",
+ val);
+ goto put_child;
+ }
+ config[num].out_cm_ampl_bits &= 0x0f;
+ config[num].out_cm_ampl_bits |= (val << 4) & 0xf0;
+ }
+
+ if (of_property_read_bool(child, "silabs,disable-high"))
+ config[num].out_format_drv_bits |= 0x10;
+
+ config[num].synth_master =
+ of_property_read_bool(child, "silabs,synth-master");
+
+ config[num].always_on =
+ of_property_read_bool(child, "always-on");
+ }
+
+ return 0;
+
+put_child:
+ of_node_put(child);
+ return -EINVAL;
+}
+
+/*
+ * If not pre-configured, calculate and set the PLL configuration manually.
+ * For low-jitter performance, the PLL should be set such that the synthesizers
+ * only need integer division.
+ * Without any user guidance, we'll set the PLL to 14GHz, which still allows
+ * the chip to generate any frequency on its outputs, but jitter performance
+ * may be sub-optimal.
+ */
+static int si5341_initialize_pll(struct clk_si5341 *data)
+{
+ struct device_node *np = data->i2c_client->dev.of_node;
+ u32 m_num = 0;
+ u32 m_den = 0;
+
+ if (of_property_read_u32(np, "silabs,pll-m-num", &m_num)) {
+ dev_err(&data->i2c_client->dev,
+ "PLL configuration requires silabs,pll-m-num\n");
+ }
+ if (of_property_read_u32(np, "silabs,pll-m-den", &m_den)) {
+ dev_err(&data->i2c_client->dev,
+ "PLL configuration requires silabs,pll-m-den\n");
+ }
+
+ if (!m_num || !m_den) {
+ dev_err(&data->i2c_client->dev,
+ "PLL configuration invalid, assume 14GHz\n");
+ m_den = clk_get_rate(data->pxtal) / 10;
+ m_num = 1400000000;
+ }
+
+ return si5341_encode_44_32(data->regmap,
+ SI5341_PLL_M_NUM, m_num, m_den);
+}
+
+static int si5341_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct clk_si5341 *data;
+ struct clk_init_data init;
+ const char *root_clock_name;
+ const char *synth_clock_names[SI5341_NUM_SYNTH];
+ int err;
+ unsigned int i;
+ struct clk_si5341_output_config config[SI5341_MAX_NUM_OUTPUTS];
+ bool initialization_required;
+
+ data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ data->i2c_client = client;
+
+ data->pxtal = devm_clk_get(&client->dev, "xtal");
+ if (IS_ERR(data->pxtal)) {
+ if (PTR_ERR(data->pxtal) == -EPROBE_DEFER)
+ return -EPROBE_DEFER;
+
+ dev_err(&client->dev, "Missing xtal clock input\n");
+ }
+
+ err = si5341_dt_parse_dt(client, config);
+ if (err)
+ return err;
+
+ if (of_property_read_string(client->dev.of_node, "clock-output-names",
+ &init.name))
+ init.name = client->dev.of_node->name;
+ root_clock_name = init.name;
+
+ data->regmap = devm_regmap_init_i2c(client, &si5341_regmap_config);
+ if (IS_ERR(data->regmap))
+ return PTR_ERR(data->regmap);
+
+ i2c_set_clientdata(client, data);
+
+ err = si5341_probe_chip_id(data);
+ if (err < 0)
+ return err;
+
+ /* "Activate" the xtal (usually a fixed clock) */
+ clk_prepare_enable(data->pxtal);
+
+ if (of_property_read_bool(client->dev.of_node, "silabs,reprogram")) {
+ initialization_required = true;
+ } else {
+ err = si5341_is_programmed_already(data);
+ if (err < 0)
+ return err;
+
+ initialization_required = !err;
+ }
+
+ if (initialization_required) {
+ /* Populate the regmap cache in preparation for "cache only" */
+ err = si5341_read_settings(data);
+ if (err < 0)
+ return err;
+
+ err = si5341_send_preamble(data);
+ if (err < 0)
+ return err;
+
+ /*
+ * We intend to send all 'final' register values in a single
+ * transaction. So cache all register writes until we're done
+ * configuring.
+ */
+ regcache_cache_only(data->regmap, true);
+
+ /* Write the configuration pairs from the firmware blob */
+ err = si5341_write_multiple(data, si5341_reg_defaults,
+ ARRAY_SIZE(si5341_reg_defaults));
+ if (err < 0)
+ return err;
+
+ /* PLL configuration is required */
+ err = si5341_initialize_pll(data);
+ if (err < 0)
+ return err;
+ }
+
+ /* Register the PLL */
+ data->pxtal_name = __clk_get_name(data->pxtal);
+ init.parent_names = &data->pxtal_name;
+ init.num_parents = 1; /* For now, only XTAL input supported */
+ init.ops = &si5341_clk_ops;
+ init.flags = 0;
+ data->hw.init = &init;
+
+ err = devm_clk_hw_register(&client->dev, &data->hw);
+ if (err) {
+ dev_err(&client->dev, "clock registration failed\n");
+ return err;
+ }
+
+ init.num_parents = 1;
+ init.parent_names = &root_clock_name;
+ init.ops = &si5341_synth_clk_ops;
+ for (i = 0; i < data->num_synth; ++i) {
+ synth_clock_names[i] = devm_kasprintf(&client->dev, GFP_KERNEL,
+ "%s.N%u", client->dev.of_node->name, i);
+ init.name = synth_clock_names[i];
+ data->synth[i].index = i;
+ data->synth[i].data = data;
+ data->synth[i].hw.init = &init;
+ err = devm_clk_hw_register(&client->dev, &data->synth[i].hw);
+ if (err) {
+ dev_err(&client->dev,
+ "synth N%u registration failed\n", i);
+ }
+ }
+
+ init.num_parents = data->num_synth;
+ init.parent_names = synth_clock_names;
+ init.ops = &si5341_output_clk_ops;
+ for (i = 0; i < data->num_outputs; ++i) {
+ init.name = kasprintf(GFP_KERNEL, "%s.%d",
+ client->dev.of_node->name, i);
+ init.flags = config[i].synth_master ? CLK_SET_RATE_PARENT : 0;
+ data->clk[i].index = i;
+ data->clk[i].data = data;
+ data->clk[i].hw.init = &init;
+ if (config[i].out_format_drv_bits & 0x07) {
+ regmap_write(data->regmap,
+ SI5341_OUT_FORMAT(&data->clk[i]),
+ config[i].out_format_drv_bits);
+ regmap_write(data->regmap,
+ SI5341_OUT_CM(&data->clk[i]),
+ config[i].out_cm_ampl_bits);
+ }
+ err = devm_clk_hw_register(&client->dev, &data->clk[i].hw);
+ kfree(init.name); /* clock framework made a copy of the name */
+ if (err) {
+ dev_err(&client->dev,
+ "output %u registration failed\n", i);
+ return err;
+ }
+ if (config[i].always_on)
+ clk_prepare(data->clk[i].hw.clk);
+ }
+
+ err = of_clk_add_hw_provider(client->dev.of_node, of_clk_si5341_get,
+ data);
+ if (err) {
+ dev_err(&client->dev, "unable to add clk provider\n");
+ return err;
+ }
+
+ if (initialization_required) {
+ /* Synchronize */
+ regcache_cache_only(data->regmap, false);
+ err = regcache_sync(data->regmap);
+ if (err < 0)
+ return err;
+
+ err = si5341_finalize_defaults(data);
+ if (err < 0)
+ return err;
+ }
+
+ /* Free the names, clk framework makes copies */
+ for (i = 0; i < data->num_synth; ++i)
+ devm_kfree(&client->dev, (void *)synth_clock_names[i]);
+
+ return 0;
+}
+
+static const struct i2c_device_id si5341_id[] = {
+ { "si5340", 0 },
+ { "si5341", 1 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, si5341_id);
+
+static const struct of_device_id clk_si5341_of_match[] = {
+ { .compatible = "silabs,si5340" },
+ { .compatible = "silabs,si5341" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, clk_si5341_of_match);
+
+static struct i2c_driver si5341_driver = {
+ .driver = {
+ .name = "si5341",
+ .of_match_table = clk_si5341_of_match,
+ },
+ .probe = si5341_probe,
+ .id_table = si5341_id,
+};
+module_i2c_driver(si5341_driver);
+
+MODULE_AUTHOR("Mike Looijmans <mike.looijmans@topic.nl>");
+MODULE_DESCRIPTION("Si5341 driver");
+MODULE_LICENSE("GPL");
projects / platform / kernel / linux-rpi.git / commitdiff