The SPICC controller in Meson-AXG SoC is capable of using a linear clock divider to reach a much fine tuned range of clocks, while the old controller only use a power of two clock divider, result at a more coarse clock range.
Also convert the clock registration into Common Clock Framework. Signed-off-by: Sunny Luo <[email protected]> Signed-off-by: Yixun Lan <[email protected]> --- drivers/spi/Kconfig | 2 +- drivers/spi/spi-meson-spicc.c | 209 ++++++++++++++++++++++++++++++++++-------- 2 files changed, 170 insertions(+), 41 deletions(-) diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig index 9f89cb1..75f7362 100644 --- a/drivers/spi/Kconfig +++ b/drivers/spi/Kconfig @@ -384,7 +384,7 @@ config SPI_FSL_ESPI config SPI_MESON_SPICC tristate "Amlogic Meson SPICC controller" - depends on ARCH_MESON || COMPILE_TEST + depends on OF && COMMON_CLK && (ARCH_MESON || COMPILE_TEST) help This enables master mode support for the SPICC (SPI communication controller) available in Amlogic Meson SoCs. diff --git a/drivers/spi/spi-meson-spicc.c b/drivers/spi/spi-meson-spicc.c index 0384c28..59af18e 100644 --- a/drivers/spi/spi-meson-spicc.c +++ b/drivers/spi/spi-meson-spicc.c @@ -116,6 +116,9 @@ #define SPICC_DWADDR 0x24 /* Write Address of DMA */ #define SPICC_ENH_CTL0 0x38 /* Enhanced Feature */ +#define SPICC_ENH_CLK_CS_DELAY_MASK GENMASK(15, 0) +#define SPICC_ENH_DATARATE_MASK GENMASK(23, 16) +#define SPICC_ENH_DATARATE_EN BIT(24) #define SPICC_ENH_MOSI_OEN BIT(25) #define SPICC_ENH_CLK_OEN BIT(26) #define SPICC_ENH_CS_OEN BIT(27) @@ -131,6 +134,7 @@ struct meson_spicc_data { unsigned int max_speed_hz; bool has_oen; + bool has_enhance_clk_div; }; struct meson_spicc_device { @@ -138,6 +142,7 @@ struct meson_spicc_device { struct platform_device *pdev; void __iomem *base; struct clk *core; + struct clk *clk; struct spi_message *message; struct spi_transfer *xfer; const struct meson_spicc_data *data; @@ -325,40 +330,6 @@ static irqreturn_t meson_spicc_irq(int irq, void *data) return IRQ_HANDLED; } -static u32 meson_spicc_setup_speed(struct meson_spicc_device *spicc, u32 conf, - u32 speed) -{ - unsigned long parent, value; - unsigned int i, div; - - parent = clk_get_rate(spicc->core); - - /* Find closest inferior/equal possible speed */ - for (i = 0 ; i < 7 ; ++i) { - /* 2^(data_rate+2) */ - value = parent >> (i + 2); - - if (value <= speed) - break; - } - - /* If provided speed it lower than max divider, use max divider */ - if (i > 7) { - div = 7; - dev_warn_once(&spicc->pdev->dev, "unable to get close to speed %u\n", - speed); - } else - div = i; - - dev_dbg(&spicc->pdev->dev, "parent %lu, speed %u -> %lu (%u)\n", - parent, speed, value, div); - - conf &= ~SPICC_DATARATE_MASK; - conf |= FIELD_PREP(SPICC_DATARATE_MASK, div); - - return conf; -} - static void meson_spicc_setup_xfer(struct meson_spicc_device *spicc, struct spi_transfer *xfer) { @@ -367,9 +338,6 @@ static void meson_spicc_setup_xfer(struct meson_spicc_device *spicc, /* Read original configuration */ conf = conf_orig = readl_relaxed(spicc->base + SPICC_CONREG); - /* Select closest divider */ - conf = meson_spicc_setup_speed(spicc, conf, xfer->speed_hz); - /* Setup word width */ conf &= ~SPICC_BITLENGTH_MASK; conf |= FIELD_PREP(SPICC_BITLENGTH_MASK, @@ -378,6 +346,8 @@ static void meson_spicc_setup_xfer(struct meson_spicc_device *spicc, /* Ignore if unchanged */ if (conf != conf_orig) writel_relaxed(conf, spicc->base + SPICC_CONREG); + + clk_set_rate(spicc->clk, xfer->speed_hz); } static int meson_spicc_transfer_one(struct spi_master *master, @@ -486,9 +456,6 @@ static int meson_spicc_unprepare_transfer(struct spi_master *master) /* Disable all IRQs */ writel(0, spicc->base + SPICC_INTREG); - /* Disable controller */ - writel_bits_relaxed(SPICC_ENABLE, 0, spicc->base + SPICC_CONREG); - device_reset_optional(&spicc->pdev->dev); return 0; @@ -528,6 +495,157 @@ static void meson_spicc_cleanup(struct spi_device *spi) spi->controller_state = NULL; } +/* + * The Clock Mux + * x-----------------x x------------x x------\ + * |---| 0) fixed factor |---| 1) old div |----| | + * | x-----------------x x------------x | | + * src ---| |5) mux|-- out + * | x-----------------x x------------x | | + * |---| 2) fixed factor |---| 3) new div |0---| | + * x-----------------x x------------x x------/ + * + * Clk path for GX series: + * src -> 0 -> 1 -> out + * + * Clk path for AXG series: + * src -> 0 -> 1 -> 5 -> out + * src -> 2 -> 3 -> 5 -> out + */ + +/* algorithm for div0 + div1: rate = freq / 4 / (2 ^ N) */ +static struct clk_fixed_factor meson_spicc_div0 = { + .mult = 1, + .div = 4, +}; + +static struct clk_divider meson_spicc_div1 = { + .reg = (void *)SPICC_CONREG, + .shift = 16, + .width = 3, + .flags = CLK_DIVIDER_POWER_OF_TWO, +}; + +/* algorithm for div2 + div3: rate = freq / 2 / (N + 1) */ +static struct clk_fixed_factor meson_spicc_div2 = { + .mult = 1, + .div = 2, +}; + +static struct clk_divider meson_spicc_div3 = { + .reg = (void *)SPICC_ENH_CTL0, + .shift = 16, + .width = 8, +}; + +static struct clk_mux meson_spicc_sel = { + .reg = (void *)SPICC_ENH_CTL0, + .mask = 0x1, + .shift = 24, +}; + +static int meson_spicc_clk_init(struct meson_spicc_device *spicc) +{ + struct device *dev = &spicc->pdev->dev; + struct clk_fixed_factor *div0; + struct clk_divider *div1; + struct clk_mux *mux; + struct clk_init_data init; + struct clk *clk; + const char *parent_names[1]; + const char *mux_parent_names[2]; + char name[32]; + + div0 = &meson_spicc_div0; + snprintf(name, sizeof(name), "%s#_div0", dev_name(dev)); + init.name = name; + init.ops = &clk_fixed_factor_ops; + init.flags = 0; + parent_names[0] = __clk_get_name(spicc->core); + init.parent_names = parent_names; + init.num_parents = 1; + + div0->hw.init = &init; + + clk = devm_clk_register(dev, &div0->hw); + if (WARN_ON(IS_ERR(clk))) + return PTR_ERR(clk); + + div1 = &meson_spicc_div1; + snprintf(name, sizeof(name), "%s#_div1", dev_name(dev)); + init.name = name; + init.ops = &clk_divider_ops; + init.flags = CLK_SET_RATE_PARENT; + parent_names[0] = __clk_get_name(clk); + init.parent_names = parent_names; + init.num_parents = 1; + + div1->reg = spicc->base + (u64)div1->reg; + div1->hw.init = &init; + + clk = devm_clk_register(dev, &div1->hw); + if (WARN_ON(IS_ERR(clk))) + return PTR_ERR(clk); + + if (!spicc->data->has_enhance_clk_div) { + spicc->clk = clk; + return 0; + } + + mux_parent_names[0] = __clk_get_name(clk); + + div0 = &meson_spicc_div2; + snprintf(name, sizeof(name), "%s#_div2", dev_name(dev)); + init.name = name; + init.ops = &clk_fixed_factor_ops; + init.flags = 0; + parent_names[0] = __clk_get_name(spicc->core); + init.parent_names = parent_names; + init.num_parents = 1; + + div0->hw.init = &init; + + clk = devm_clk_register(dev, &div0->hw); + if (WARN_ON(IS_ERR(clk))) + return PTR_ERR(clk); + + div1 = &meson_spicc_div3; + snprintf(name, sizeof(name), "%s#_div3", dev_name(dev)); + init.name = name; + init.ops = &clk_divider_ops; + init.flags = CLK_SET_RATE_PARENT; + parent_names[0] = __clk_get_name(clk); + init.parent_names = parent_names; + init.num_parents = 1; + + div1->reg = spicc->base + (u64)div1->reg; + div1->hw.init = &init; + + clk = devm_clk_register(dev, &div1->hw); + if (WARN_ON(IS_ERR(clk))) + return PTR_ERR(clk); + + mux_parent_names[1] = __clk_get_name(clk); + + mux = &meson_spicc_sel; + snprintf(name, sizeof(name), "%s#_sel", dev_name(dev)); + init.name = name; + init.ops = &clk_mux_ops; + init.parent_names = mux_parent_names; + init.num_parents = 2; + init.flags = CLK_SET_RATE_PARENT | CLK_SET_RATE_NO_REPARENT; + + mux->reg = spicc->base + (u64)mux->reg; + mux->hw.init = &init; + + spicc->clk = devm_clk_register(dev, &mux->hw); + if (WARN_ON(IS_ERR(spicc->clk))) + return PTR_ERR(spicc->clk); + + clk_set_parent(spicc->clk, clk); + return 0; +} + static int meson_spicc_probe(struct platform_device *pdev) { struct spi_master *master; @@ -557,6 +675,10 @@ static int meson_spicc_probe(struct platform_device *pdev) goto out_master; } + /* Set master mode and enable controller */ + writel_relaxed(SPICC_ENABLE | SPICC_MODE_MASTER, + spicc->base + SPICC_CONREG); + /* Disable all IRQs */ writel_relaxed(0, spicc->base + SPICC_INTREG); @@ -603,6 +725,12 @@ static int meson_spicc_probe(struct platform_device *pdev) master->max_speed_hz = min_t(unsigned int, rate >> 1, spicc->data->max_speed_hz); + ret = meson_spicc_clk_init(spicc); + if (ret) { + dev_err(&pdev->dev, "clock registration failed\n"); + goto out_master; + } + ret = devm_spi_register_master(&pdev->dev, master); if (ret) { dev_err(&pdev->dev, "spi master registration failed\n"); @@ -639,6 +767,7 @@ static const struct meson_spicc_data meson_spicc_gx_data = { static const struct meson_spicc_data meson_spicc_axg_data = { .max_speed_hz = 80000000, .has_oen = true, + .has_enhance_clk_div = true, }; static const struct of_device_id meson_spicc_of_match[] = { -- 2.7.4
