diff options
Diffstat (limited to 'drivers/clk/clk-si5341.c')
| -rw-r--r-- | drivers/clk/clk-si5341.c | 212 |
1 files changed, 196 insertions, 16 deletions
diff --git a/drivers/clk/clk-si5341.c b/drivers/clk/clk-si5341.c index 6e780c2a9e6b..3c228b018116 100644 --- a/drivers/clk/clk-si5341.c +++ b/drivers/clk/clk-si5341.c @@ -16,6 +16,8 @@ #include <linux/slab.h> #include <asm/unaligned.h> +#define SI5341_NUM_INPUTS 4 + #define SI5341_MAX_NUM_OUTPUTS 10 #define SI5340_MAX_NUM_OUTPUTS 4 @@ -56,8 +58,8 @@ struct clk_si5341 { 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; + struct clk *input_clk[SI5341_NUM_INPUTS]; + const char *input_clk_name[SI5341_NUM_INPUTS]; const u16 *reg_output_offset; const u16 *reg_rdiv_offset; u64 freq_vco; /* 13500–14256 MHz */ @@ -78,10 +80,25 @@ struct clk_si5341_output_config { #define SI5341_DEVICE_REV 0x0005 #define SI5341_STATUS 0x000C #define SI5341_SOFT_RST 0x001C +#define SI5341_IN_SEL 0x0021 +#define SI5341_XAXB_CFG 0x090E +#define SI5341_IN_EN 0x0949 +#define SI5341_INX_TO_PFD_EN 0x094A + +/* Input selection */ +#define SI5341_IN_SEL_MASK 0x06 +#define SI5341_IN_SEL_SHIFT 1 +#define SI5341_IN_SEL_REGCTRL 0x01 +#define SI5341_INX_TO_PFD_SHIFT 4 + +/* XTAL config bits */ +#define SI5341_XAXB_CFG_EXTCLK_EN BIT(0) +#define SI5341_XAXB_CFG_PDNB BIT(1) /* Input dividers (48-bit) */ #define SI5341_IN_PDIV(x) (0x0208 + ((x) * 10)) #define SI5341_IN_PSET(x) (0x020E + ((x) * 10)) +#define SI5341_PX_UPD 0x0230 /* PLL configuration */ #define SI5341_PLL_M_NUM 0x0235 @@ -120,6 +137,10 @@ struct si5341_reg_default { u8 value; }; +static const char * const si5341_input_clock_names[] = { + "in0", "in1", "in2", "xtal" +}; + /* Output configuration registers 0..9 are not quite logically organized */ static const u16 si5341_reg_output_offset[] = { 0x0108, @@ -390,7 +411,112 @@ static unsigned long si5341_clk_recalc_rate(struct clk_hw *hw, return (unsigned long)res; } +static int si5341_clk_get_selected_input(struct clk_si5341 *data) +{ + int err; + u32 val; + + err = regmap_read(data->regmap, SI5341_IN_SEL, &val); + if (err < 0) + return err; + + return (val & SI5341_IN_SEL_MASK) >> SI5341_IN_SEL_SHIFT; +} + +static u8 si5341_clk_get_parent(struct clk_hw *hw) +{ + struct clk_si5341 *data = to_clk_si5341(hw); + int res = si5341_clk_get_selected_input(data); + + if (res < 0) + return 0; /* Apparently we cannot report errors */ + + return res; +} + +static int si5341_clk_reparent(struct clk_si5341 *data, u8 index) +{ + int err; + u8 val; + + val = (index << SI5341_IN_SEL_SHIFT) & SI5341_IN_SEL_MASK; + /* Enable register-based input selection */ + val |= SI5341_IN_SEL_REGCTRL; + + err = regmap_update_bits(data->regmap, + SI5341_IN_SEL, SI5341_IN_SEL_REGCTRL | SI5341_IN_SEL_MASK, val); + if (err < 0) + return err; + + if (index < 3) { + /* Enable input buffer for selected input */ + err = regmap_update_bits(data->regmap, + SI5341_IN_EN, 0x07, BIT(index)); + if (err < 0) + return err; + + /* Enables the input to phase detector */ + err = regmap_update_bits(data->regmap, SI5341_INX_TO_PFD_EN, + 0x7 << SI5341_INX_TO_PFD_SHIFT, + BIT(index + SI5341_INX_TO_PFD_SHIFT)); + if (err < 0) + return err; + + /* Power down XTAL oscillator and buffer */ + err = regmap_update_bits(data->regmap, SI5341_XAXB_CFG, + SI5341_XAXB_CFG_PDNB, 0); + if (err < 0) + return err; + + /* + * Set the P divider to "1". There's no explanation in the + * datasheet of these registers, but the clockbuilder software + * programs a "1" when the input is being used. + */ + err = regmap_write(data->regmap, SI5341_IN_PDIV(index), 1); + if (err < 0) + return err; + + err = regmap_write(data->regmap, SI5341_IN_PSET(index), 1); + if (err < 0) + return err; + + /* Set update PDIV bit */ + err = regmap_write(data->regmap, SI5341_PX_UPD, BIT(index)); + if (err < 0) + return err; + } else { + /* Disable all input buffers */ + err = regmap_update_bits(data->regmap, SI5341_IN_EN, 0x07, 0); + if (err < 0) + return err; + + /* Disable input to phase detector */ + err = regmap_update_bits(data->regmap, SI5341_INX_TO_PFD_EN, + 0x7 << SI5341_INX_TO_PFD_SHIFT, 0); + if (err < 0) + return err; + + /* Power up XTAL oscillator and buffer */ + err = regmap_update_bits(data->regmap, SI5341_XAXB_CFG, + SI5341_XAXB_CFG_PDNB, SI5341_XAXB_CFG_PDNB); + if (err < 0) + return err; + } + + return 0; +} + +static int si5341_clk_set_parent(struct clk_hw *hw, u8 index) +{ + struct clk_si5341 *data = to_clk_si5341(hw); + + return si5341_clk_reparent(data, index); +} + static const struct clk_ops si5341_clk_ops = { + .set_parent = si5341_clk_set_parent, + .get_parent = si5341_clk_get_parent, .recalc_rate = si5341_clk_recalc_rate, }; @@ -985,7 +1111,8 @@ 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 */ + /* Update bits for P divider and synth config */ + regmap_reg_range(SI5341_PX_UPD, SI5341_PX_UPD), 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)), @@ -1122,6 +1249,7 @@ 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; + int sel; if (of_property_read_u32(np, "silabs,pll-m-num", &m_num)) { dev_err(&data->i2c_client->dev, @@ -1135,7 +1263,11 @@ static int si5341_initialize_pll(struct clk_si5341 *data) 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; + sel = si5341_clk_get_selected_input(data); + if (sel < 0) + return sel; + + m_den = clk_get_rate(data->input_clk[sel]) / 10; m_num = 1400000000; } @@ -1143,11 +1275,52 @@ static int si5341_initialize_pll(struct clk_si5341 *data) SI5341_PLL_M_NUM, m_num, m_den); } +static int si5341_clk_select_active_input(struct clk_si5341 *data) +{ + int res; + int err; + int i; + + res = si5341_clk_get_selected_input(data); + if (res < 0) + return res; + + /* If the current register setting is invalid, pick the first input */ + if (!data->input_clk[res]) { + dev_dbg(&data->i2c_client->dev, + "Input %d not connected, rerouting\n", res); + res = -ENODEV; + for (i = 0; i < SI5341_NUM_INPUTS; ++i) { + if (data->input_clk[i]) { + res = i; + break; + } + } + if (res < 0) { + dev_err(&data->i2c_client->dev, + "No clock input available\n"); + return res; + } + } + + /* Make sure the selected clock is also enabled and routed */ + err = si5341_clk_reparent(data, res); + if (err < 0) + return err; + + err = clk_prepare_enable(data->input_clk[res]); + if (err < 0) + return err; + + return res; +} + static int si5341_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct clk_si5341 *data; struct clk_init_data init; + struct clk *input; const char *root_clock_name; const char *synth_clock_names[SI5341_NUM_SYNTH]; int err; @@ -1161,12 +1334,16 @@ static int si5341_probe(struct i2c_client *client, 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"); + for (i = 0; i < SI5341_NUM_INPUTS; ++i) { + input = devm_clk_get(&client->dev, si5341_input_clock_names[i]); + if (IS_ERR(input)) { + if (PTR_ERR(input) == -EPROBE_DEFER) + return -EPROBE_DEFER; + data->input_clk_name[i] = si5341_input_clock_names[i]; + } else { + data->input_clk[i] = input; + data->input_clk_name[i] = __clk_get_name(input); + } } err = si5341_dt_parse_dt(client, config); @@ -1188,9 +1365,6 @@ static int si5341_probe(struct i2c_client *client, 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 { @@ -1223,7 +1397,14 @@ static int si5341_probe(struct i2c_client *client, ARRAY_SIZE(si5341_reg_defaults)); if (err < 0) return err; + } + + /* Input must be up and running at this point */ + err = si5341_clk_select_active_input(data); + if (err < 0) + return err; + if (initialization_required) { /* PLL configuration is required */ err = si5341_initialize_pll(data); if (err < 0) @@ -1231,9 +1412,8 @@ static int si5341_probe(struct i2c_client *client, } /* 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.parent_names = data->input_clk_name; + init.num_parents = SI5341_NUM_INPUTS; init.ops = &si5341_clk_ops; init.flags = 0; data->hw.init = &init; |