From 38867cb7ec90253289cab22c13282a3ef6530f69 Mon Sep 17 00:00:00 2001 From: Damien Hedde Date: Mon, 6 Apr 2020 15:52:48 +0200 Subject: [PATCH] hw/misc/zynq_slcr: add clock generation for uarts Add some clocks to zynq_slcr + the main input clock (ps_clk) + the reference clock outputs for each uart (uart0 & 1) This commit also transitional the slcr to multi-phase reset as it is required to initialize the clocks correctly. The clock frequencies are computed using the internal pll & uart configuration registers and the input ps_clk frequency. Signed-off-by: Damien Hedde Reviewed-by: Edgar E. Iglesias Acked-by: Alistair Francis Message-id: 20200406135251.157596-7-damien.hedde@greensocs.com Signed-off-by: Peter Maydell --- hw/misc/zynq_slcr.c | 172 ++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 168 insertions(+), 4 deletions(-) diff --git a/hw/misc/zynq_slcr.c b/hw/misc/zynq_slcr.c index b9a38272d9..f7472d1f3c 100644 --- a/hw/misc/zynq_slcr.c +++ b/hw/misc/zynq_slcr.c @@ -22,6 +22,7 @@ #include "qemu/log.h" #include "qemu/module.h" #include "hw/registerfields.h" +#include "hw/qdev-clock.h" #ifndef ZYNQ_SLCR_ERR_DEBUG #define ZYNQ_SLCR_ERR_DEBUG 0 @@ -45,6 +46,12 @@ REG32(LOCKSTA, 0x00c) REG32(ARM_PLL_CTRL, 0x100) REG32(DDR_PLL_CTRL, 0x104) REG32(IO_PLL_CTRL, 0x108) +/* fields for [ARM|DDR|IO]_PLL_CTRL registers */ + FIELD(xxx_PLL_CTRL, PLL_RESET, 0, 1) + FIELD(xxx_PLL_CTRL, PLL_PWRDWN, 1, 1) + FIELD(xxx_PLL_CTRL, PLL_BYPASS_QUAL, 3, 1) + FIELD(xxx_PLL_CTRL, PLL_BYPASS_FORCE, 4, 1) + FIELD(xxx_PLL_CTRL, PLL_FPDIV, 12, 7) REG32(PLL_STATUS, 0x10c) REG32(ARM_PLL_CFG, 0x110) REG32(DDR_PLL_CFG, 0x114) @@ -64,6 +71,10 @@ REG32(SMC_CLK_CTRL, 0x148) REG32(LQSPI_CLK_CTRL, 0x14c) REG32(SDIO_CLK_CTRL, 0x150) REG32(UART_CLK_CTRL, 0x154) + FIELD(UART_CLK_CTRL, CLKACT0, 0, 1) + FIELD(UART_CLK_CTRL, CLKACT1, 1, 1) + FIELD(UART_CLK_CTRL, SRCSEL, 4, 2) + FIELD(UART_CLK_CTRL, DIVISOR, 8, 6) REG32(SPI_CLK_CTRL, 0x158) REG32(CAN_CLK_CTRL, 0x15c) REG32(CAN_MIOCLK_CTRL, 0x160) @@ -179,11 +190,127 @@ typedef struct ZynqSLCRState { MemoryRegion iomem; uint32_t regs[ZYNQ_SLCR_NUM_REGS]; + + Clock *ps_clk; + Clock *uart0_ref_clk; + Clock *uart1_ref_clk; } ZynqSLCRState; -static void zynq_slcr_reset(DeviceState *d) +/* + * return the output frequency of ARM/DDR/IO pll + * using input frequency and PLL_CTRL register + */ +static uint64_t zynq_slcr_compute_pll(uint64_t input, uint32_t ctrl_reg) { - ZynqSLCRState *s = ZYNQ_SLCR(d); + uint32_t mult = ((ctrl_reg & R_xxx_PLL_CTRL_PLL_FPDIV_MASK) >> + R_xxx_PLL_CTRL_PLL_FPDIV_SHIFT); + + /* first, check if pll is bypassed */ + if (ctrl_reg & R_xxx_PLL_CTRL_PLL_BYPASS_FORCE_MASK) { + return input; + } + + /* is pll disabled ? */ + if (ctrl_reg & (R_xxx_PLL_CTRL_PLL_RESET_MASK | + R_xxx_PLL_CTRL_PLL_PWRDWN_MASK)) { + return 0; + } + + /* frequency multiplier -> period division */ + return input / mult; +} + +/* + * return the output period of a clock given: + * + the periods in an array corresponding to input mux selector + * + the register xxx_CLK_CTRL value + * + enable bit index in ctrl register + * + * This function makes the assumption that the ctrl_reg value is organized as + * follows: + * + bits[13:8] clock frequency divisor + * + bits[5:4] clock mux selector (index in array) + * + bits[index] clock enable + */ +static uint64_t zynq_slcr_compute_clock(const uint64_t periods[], + uint32_t ctrl_reg, + unsigned index) +{ + uint32_t srcsel = extract32(ctrl_reg, 4, 2); /* bits [5:4] */ + uint32_t divisor = extract32(ctrl_reg, 8, 6); /* bits [13:8] */ + + /* first, check if clock is disabled */ + if (((ctrl_reg >> index) & 1u) == 0) { + return 0; + } + + /* + * according to the Zynq technical ref. manual UG585 v1.12.2 in + * Clocks chapter, section 25.10.1 page 705: + * "The 6-bit divider provides a divide range of 1 to 63" + * We follow here what is implemented in linux kernel and consider + * the 0 value as a bypass (no division). + */ + /* frequency divisor -> period multiplication */ + return periods[srcsel] * (divisor ? divisor : 1u); +} + +/* + * macro helper around zynq_slcr_compute_clock to avoid repeating + * the register name. + */ +#define ZYNQ_COMPUTE_CLK(state, plls, reg, enable_field) \ + zynq_slcr_compute_clock((plls), (state)->regs[reg], \ + reg ## _ ## enable_field ## _SHIFT) + +/** + * Compute and set the ouputs clocks periods. + * But do not propagate them further. Connected clocks + * will not receive any updates (See zynq_slcr_compute_clocks()) + */ +static void zynq_slcr_compute_clocks(ZynqSLCRState *s) +{ + uint64_t ps_clk = clock_get(s->ps_clk); + + /* consider outputs clocks are disabled while in reset */ + if (device_is_in_reset(DEVICE(s))) { + ps_clk = 0; + } + + uint64_t io_pll = zynq_slcr_compute_pll(ps_clk, s->regs[R_IO_PLL_CTRL]); + uint64_t arm_pll = zynq_slcr_compute_pll(ps_clk, s->regs[R_ARM_PLL_CTRL]); + uint64_t ddr_pll = zynq_slcr_compute_pll(ps_clk, s->regs[R_DDR_PLL_CTRL]); + + uint64_t uart_mux[4] = {io_pll, io_pll, arm_pll, ddr_pll}; + + /* compute uartX reference clocks */ + clock_set(s->uart0_ref_clk, + ZYNQ_COMPUTE_CLK(s, uart_mux, R_UART_CLK_CTRL, CLKACT0)); + clock_set(s->uart1_ref_clk, + ZYNQ_COMPUTE_CLK(s, uart_mux, R_UART_CLK_CTRL, CLKACT1)); +} + +/** + * Propagate the outputs clocks. + * zynq_slcr_compute_clocks() should have been called before + * to configure them. + */ +static void zynq_slcr_propagate_clocks(ZynqSLCRState *s) +{ + clock_propagate(s->uart0_ref_clk); + clock_propagate(s->uart1_ref_clk); +} + +static void zynq_slcr_ps_clk_callback(void *opaque) +{ + ZynqSLCRState *s = (ZynqSLCRState *) opaque; + zynq_slcr_compute_clocks(s); + zynq_slcr_propagate_clocks(s); +} + +static void zynq_slcr_reset_init(Object *obj, ResetType type) +{ + ZynqSLCRState *s = ZYNQ_SLCR(obj); int i; DB_PRINT("RESET\n"); @@ -277,6 +404,23 @@ static void zynq_slcr_reset(DeviceState *d) s->regs[R_DDRIOB + 12] = 0x00000021; } +static void zynq_slcr_reset_hold(Object *obj) +{ + ZynqSLCRState *s = ZYNQ_SLCR(obj); + + /* will disable all output clocks */ + zynq_slcr_compute_clocks(s); + zynq_slcr_propagate_clocks(s); +} + +static void zynq_slcr_reset_exit(Object *obj) +{ + ZynqSLCRState *s = ZYNQ_SLCR(obj); + + /* will compute output clocks according to ps_clk and registers */ + zynq_slcr_compute_clocks(s); + zynq_slcr_propagate_clocks(s); +} static bool zynq_slcr_check_offset(hwaddr offset, bool rnw) { @@ -409,6 +553,13 @@ static void zynq_slcr_write(void *opaque, hwaddr offset, qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_RESET); } break; + case R_IO_PLL_CTRL: + case R_ARM_PLL_CTRL: + case R_DDR_PLL_CTRL: + case R_UART_CLK_CTRL: + zynq_slcr_compute_clocks(s); + zynq_slcr_propagate_clocks(s); + break; } } @@ -418,6 +569,13 @@ static const MemoryRegionOps slcr_ops = { .endianness = DEVICE_NATIVE_ENDIAN, }; +static const ClockPortInitArray zynq_slcr_clocks = { + QDEV_CLOCK_IN(ZynqSLCRState, ps_clk, zynq_slcr_ps_clk_callback), + QDEV_CLOCK_OUT(ZynqSLCRState, uart0_ref_clk), + QDEV_CLOCK_OUT(ZynqSLCRState, uart1_ref_clk), + QDEV_CLOCK_END +}; + static void zynq_slcr_init(Object *obj) { ZynqSLCRState *s = ZYNQ_SLCR(obj); @@ -425,14 +583,17 @@ static void zynq_slcr_init(Object *obj) memory_region_init_io(&s->iomem, obj, &slcr_ops, s, "slcr", ZYNQ_SLCR_MMIO_SIZE); sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->iomem); + + qdev_init_clocks(DEVICE(obj), zynq_slcr_clocks); } static const VMStateDescription vmstate_zynq_slcr = { .name = "zynq_slcr", - .version_id = 2, + .version_id = 3, .minimum_version_id = 2, .fields = (VMStateField[]) { VMSTATE_UINT32_ARRAY(regs, ZynqSLCRState, ZYNQ_SLCR_NUM_REGS), + VMSTATE_CLOCK_V(ps_clk, ZynqSLCRState, 3), VMSTATE_END_OF_LIST() } }; @@ -440,9 +601,12 @@ static const VMStateDescription vmstate_zynq_slcr = { static void zynq_slcr_class_init(ObjectClass *klass, void *data) { DeviceClass *dc = DEVICE_CLASS(klass); + ResettableClass *rc = RESETTABLE_CLASS(klass); dc->vmsd = &vmstate_zynq_slcr; - dc->reset = zynq_slcr_reset; + rc->phases.enter = zynq_slcr_reset_init; + rc->phases.hold = zynq_slcr_reset_hold; + rc->phases.exit = zynq_slcr_reset_exit; } static const TypeInfo zynq_slcr_info = {