diff options
Diffstat (limited to 'drivers/w1/masters/ds1wm.c')
| -rw-r--r-- | drivers/w1/masters/ds1wm.c | 582 |
1 files changed, 582 insertions, 0 deletions
diff --git a/drivers/w1/masters/ds1wm.c b/drivers/w1/masters/ds1wm.c new file mode 100644 index 000000000..e0b8a4bc7 --- /dev/null +++ b/drivers/w1/masters/ds1wm.c @@ -0,0 +1,582 @@ +/* + * 1-wire busmaster driver for DS1WM and ASICs with embedded DS1WMs + * such as HP iPAQs (including h5xxx, h2200, and devices with ASIC3 + * like hx4700). + * + * Copyright (c) 2004-2005, Szabolcs Gyurko <szabolcs.gyurko@tlt.hu> + * Copyright (c) 2004-2007, Matt Reimer <mreimer@vpop.net> + * + * Use consistent with the GNU GPL is permitted, + * provided that this copyright notice is + * preserved in its entirety in all copies and derived works. + */ + +#include <linux/module.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/irq.h> +#include <linux/pm.h> +#include <linux/platform_device.h> +#include <linux/err.h> +#include <linux/delay.h> +#include <linux/mfd/core.h> +#include <linux/mfd/ds1wm.h> +#include <linux/slab.h> + +#include <asm/io.h> + +#include "../w1.h" +#include "../w1_int.h" + + +#define DS1WM_CMD 0x00 /* R/W 4 bits command */ +#define DS1WM_DATA 0x01 /* R/W 8 bits, transmit/receive buffer */ +#define DS1WM_INT 0x02 /* R/W interrupt status */ +#define DS1WM_INT_EN 0x03 /* R/W interrupt enable */ +#define DS1WM_CLKDIV 0x04 /* R/W 5 bits of divisor and pre-scale */ +#define DS1WM_CNTRL 0x05 /* R/W master control register (not used yet) */ + +#define DS1WM_CMD_1W_RESET (1 << 0) /* force reset on 1-wire bus */ +#define DS1WM_CMD_SRA (1 << 1) /* enable Search ROM accelerator mode */ +#define DS1WM_CMD_DQ_OUTPUT (1 << 2) /* write only - forces bus low */ +#define DS1WM_CMD_DQ_INPUT (1 << 3) /* read only - reflects state of bus */ +#define DS1WM_CMD_RST (1 << 5) /* software reset */ +#define DS1WM_CMD_OD (1 << 7) /* overdrive */ + +#define DS1WM_INT_PD (1 << 0) /* presence detect */ +#define DS1WM_INT_PDR (1 << 1) /* presence detect result */ +#define DS1WM_INT_TBE (1 << 2) /* tx buffer empty */ +#define DS1WM_INT_TSRE (1 << 3) /* tx shift register empty */ +#define DS1WM_INT_RBF (1 << 4) /* rx buffer full */ +#define DS1WM_INT_RSRF (1 << 5) /* rx shift register full */ + +#define DS1WM_INTEN_EPD (1 << 0) /* enable presence detect int */ +#define DS1WM_INTEN_IAS (1 << 1) /* INTR active state */ +#define DS1WM_INTEN_ETBE (1 << 2) /* enable tx buffer empty int */ +#define DS1WM_INTEN_ETMT (1 << 3) /* enable tx shift register empty int */ +#define DS1WM_INTEN_ERBF (1 << 4) /* enable rx buffer full int */ +#define DS1WM_INTEN_ERSRF (1 << 5) /* enable rx shift register full int */ +#define DS1WM_INTEN_DQO (1 << 6) /* enable direct bus driving ops */ + +#define DS1WM_INTEN_NOT_IAS (~DS1WM_INTEN_IAS) /* all but INTR active state */ + +#define DS1WM_TIMEOUT (HZ * 5) + +static struct { + unsigned long freq; + unsigned long divisor; +} freq[] = { + { 1000000, 0x80 }, + { 2000000, 0x84 }, + { 3000000, 0x81 }, + { 4000000, 0x88 }, + { 5000000, 0x82 }, + { 6000000, 0x85 }, + { 7000000, 0x83 }, + { 8000000, 0x8c }, + { 10000000, 0x86 }, + { 12000000, 0x89 }, + { 14000000, 0x87 }, + { 16000000, 0x90 }, + { 20000000, 0x8a }, + { 24000000, 0x8d }, + { 28000000, 0x8b }, + { 32000000, 0x94 }, + { 40000000, 0x8e }, + { 48000000, 0x91 }, + { 56000000, 0x8f }, + { 64000000, 0x98 }, + { 80000000, 0x92 }, + { 96000000, 0x95 }, + { 112000000, 0x93 }, + { 128000000, 0x9c }, +/* you can continue this table, consult the OPERATION - CLOCK DIVISOR + section of the ds1wm spec sheet. */ +}; + +struct ds1wm_data { + void __iomem *map; + int bus_shift; /* # of shifts to calc register offsets */ + struct platform_device *pdev; + const struct mfd_cell *cell; + int irq; + int slave_present; + void *reset_complete; + void *read_complete; + void *write_complete; + int read_error; + /* last byte received */ + u8 read_byte; + /* byte to write that makes all intr disabled, */ + /* considering active_state (IAS) (optimization) */ + u8 int_en_reg_none; + unsigned int reset_recover_delay; /* see ds1wm.h */ +}; + +static inline void ds1wm_write_register(struct ds1wm_data *ds1wm_data, u32 reg, + u8 val) +{ + __raw_writeb(val, ds1wm_data->map + (reg << ds1wm_data->bus_shift)); +} + +static inline u8 ds1wm_read_register(struct ds1wm_data *ds1wm_data, u32 reg) +{ + return __raw_readb(ds1wm_data->map + (reg << ds1wm_data->bus_shift)); +} + + +static irqreturn_t ds1wm_isr(int isr, void *data) +{ + struct ds1wm_data *ds1wm_data = data; + u8 intr; + u8 inten = ds1wm_read_register(ds1wm_data, DS1WM_INT_EN); + /* if no bits are set in int enable register (except the IAS) + than go no further, reading the regs below has side effects */ + if (!(inten & DS1WM_INTEN_NOT_IAS)) + return IRQ_NONE; + + ds1wm_write_register(ds1wm_data, + DS1WM_INT_EN, ds1wm_data->int_en_reg_none); + + /* this read action clears the INTR and certain flags in ds1wm */ + intr = ds1wm_read_register(ds1wm_data, DS1WM_INT); + + ds1wm_data->slave_present = (intr & DS1WM_INT_PDR) ? 0 : 1; + + if ((intr & DS1WM_INT_TSRE) && ds1wm_data->write_complete) { + inten &= ~DS1WM_INTEN_ETMT; + complete(ds1wm_data->write_complete); + } + if (intr & DS1WM_INT_RBF) { + /* this read clears the RBF flag */ + ds1wm_data->read_byte = ds1wm_read_register(ds1wm_data, + DS1WM_DATA); + inten &= ~DS1WM_INTEN_ERBF; + if (ds1wm_data->read_complete) + complete(ds1wm_data->read_complete); + } + if ((intr & DS1WM_INT_PD) && ds1wm_data->reset_complete) { + inten &= ~DS1WM_INTEN_EPD; + complete(ds1wm_data->reset_complete); + } + + ds1wm_write_register(ds1wm_data, DS1WM_INT_EN, inten); + return IRQ_HANDLED; +} + +static int ds1wm_reset(struct ds1wm_data *ds1wm_data) +{ + unsigned long timeleft; + DECLARE_COMPLETION_ONSTACK(reset_done); + + ds1wm_data->reset_complete = &reset_done; + + /* enable Presence detect only */ + ds1wm_write_register(ds1wm_data, DS1WM_INT_EN, DS1WM_INTEN_EPD | + ds1wm_data->int_en_reg_none); + + ds1wm_write_register(ds1wm_data, DS1WM_CMD, DS1WM_CMD_1W_RESET); + + timeleft = wait_for_completion_timeout(&reset_done, DS1WM_TIMEOUT); + ds1wm_data->reset_complete = NULL; + if (!timeleft) { + dev_err(&ds1wm_data->pdev->dev, "reset failed, timed out\n"); + return 1; + } + + if (!ds1wm_data->slave_present) { + dev_dbg(&ds1wm_data->pdev->dev, "reset: no devices found\n"); + return 1; + } + + if (ds1wm_data->reset_recover_delay) + msleep(ds1wm_data->reset_recover_delay); + + return 0; +} + +static int ds1wm_write(struct ds1wm_data *ds1wm_data, u8 data) +{ + unsigned long timeleft; + DECLARE_COMPLETION_ONSTACK(write_done); + ds1wm_data->write_complete = &write_done; + + ds1wm_write_register(ds1wm_data, DS1WM_INT_EN, + ds1wm_data->int_en_reg_none | DS1WM_INTEN_ETMT); + + ds1wm_write_register(ds1wm_data, DS1WM_DATA, data); + + timeleft = wait_for_completion_timeout(&write_done, DS1WM_TIMEOUT); + + ds1wm_data->write_complete = NULL; + if (!timeleft) { + dev_err(&ds1wm_data->pdev->dev, "write failed, timed out\n"); + return -ETIMEDOUT; + } + + return 0; +} + +static u8 ds1wm_read(struct ds1wm_data *ds1wm_data, unsigned char write_data) +{ + unsigned long timeleft; + u8 intEnable = DS1WM_INTEN_ERBF | ds1wm_data->int_en_reg_none; + DECLARE_COMPLETION_ONSTACK(read_done); + + ds1wm_read_register(ds1wm_data, DS1WM_DATA); + + ds1wm_data->read_complete = &read_done; + ds1wm_write_register(ds1wm_data, DS1WM_INT_EN, intEnable); + + ds1wm_write_register(ds1wm_data, DS1WM_DATA, write_data); + timeleft = wait_for_completion_timeout(&read_done, DS1WM_TIMEOUT); + + ds1wm_data->read_complete = NULL; + if (!timeleft) { + dev_err(&ds1wm_data->pdev->dev, "read failed, timed out\n"); + ds1wm_data->read_error = -ETIMEDOUT; + return 0xFF; + } + ds1wm_data->read_error = 0; + return ds1wm_data->read_byte; +} + +static int ds1wm_find_divisor(int gclk) +{ + int i; + + for (i = ARRAY_SIZE(freq)-1; i >= 0; --i) + if (gclk >= freq[i].freq) + return freq[i].divisor; + + return 0; +} + +static void ds1wm_up(struct ds1wm_data *ds1wm_data) +{ + int divisor; + struct device *dev = &ds1wm_data->pdev->dev; + struct ds1wm_driver_data *plat = dev_get_platdata(dev); + + if (ds1wm_data->cell->enable) + ds1wm_data->cell->enable(ds1wm_data->pdev); + + divisor = ds1wm_find_divisor(plat->clock_rate); + dev_dbg(dev, "found divisor 0x%x for clock %d\n", + divisor, plat->clock_rate); + if (divisor == 0) { + dev_err(dev, "no suitable divisor for %dHz clock\n", + plat->clock_rate); + return; + } + ds1wm_write_register(ds1wm_data, DS1WM_CLKDIV, divisor); + + /* Let the w1 clock stabilize. */ + msleep(1); + + ds1wm_reset(ds1wm_data); +} + +static void ds1wm_down(struct ds1wm_data *ds1wm_data) +{ + ds1wm_reset(ds1wm_data); + + /* Disable interrupts. */ + ds1wm_write_register(ds1wm_data, DS1WM_INT_EN, + ds1wm_data->int_en_reg_none); + + if (ds1wm_data->cell->disable) + ds1wm_data->cell->disable(ds1wm_data->pdev); +} + +/* --------------------------------------------------------------------- */ +/* w1 methods */ + +static u8 ds1wm_read_byte(void *data) +{ + struct ds1wm_data *ds1wm_data = data; + + return ds1wm_read(ds1wm_data, 0xff); +} + +static void ds1wm_write_byte(void *data, u8 byte) +{ + struct ds1wm_data *ds1wm_data = data; + + ds1wm_write(ds1wm_data, byte); +} + +static u8 ds1wm_reset_bus(void *data) +{ + struct ds1wm_data *ds1wm_data = data; + + ds1wm_reset(ds1wm_data); + + return 0; +} + +static void ds1wm_search(void *data, struct w1_master *master_dev, + u8 search_type, w1_slave_found_callback slave_found) +{ + struct ds1wm_data *ds1wm_data = data; + int i; + int ms_discrep_bit = -1; + u64 r = 0; /* holds the progress of the search */ + u64 r_prime, d; + unsigned slaves_found = 0; + unsigned int pass = 0; + + dev_dbg(&ds1wm_data->pdev->dev, "search begin\n"); + while (true) { + ++pass; + if (pass > 100) { + dev_dbg(&ds1wm_data->pdev->dev, + "too many attempts (100), search aborted\n"); + return; + } + + mutex_lock(&master_dev->bus_mutex); + if (ds1wm_reset(ds1wm_data)) { + mutex_unlock(&master_dev->bus_mutex); + dev_dbg(&ds1wm_data->pdev->dev, + "pass: %d reset error (or no slaves)\n", pass); + break; + } + + dev_dbg(&ds1wm_data->pdev->dev, + "pass: %d r : %0#18llx writing SEARCH_ROM\n", pass, r); + ds1wm_write(ds1wm_data, search_type); + dev_dbg(&ds1wm_data->pdev->dev, + "pass: %d entering ASM\n", pass); + ds1wm_write_register(ds1wm_data, DS1WM_CMD, DS1WM_CMD_SRA); + dev_dbg(&ds1wm_data->pdev->dev, + "pass: %d beginning nibble loop\n", pass); + + r_prime = 0; + d = 0; + /* we work one nibble at a time */ + /* each nibble is interleaved to form a byte */ + for (i = 0; i < 16; i++) { + + unsigned char resp, _r, _r_prime, _d; + + _r = (r >> (4*i)) & 0xf; + _r = ((_r & 0x1) << 1) | + ((_r & 0x2) << 2) | + ((_r & 0x4) << 3) | + ((_r & 0x8) << 4); + + /* writes _r, then reads back: */ + resp = ds1wm_read(ds1wm_data, _r); + + if (ds1wm_data->read_error) { + dev_err(&ds1wm_data->pdev->dev, + "pass: %d nibble: %d read error\n", pass, i); + break; + } + + _r_prime = ((resp & 0x02) >> 1) | + ((resp & 0x08) >> 2) | + ((resp & 0x20) >> 3) | + ((resp & 0x80) >> 4); + + _d = ((resp & 0x01) >> 0) | + ((resp & 0x04) >> 1) | + ((resp & 0x10) >> 2) | + ((resp & 0x40) >> 3); + + r_prime |= (unsigned long long) _r_prime << (i * 4); + d |= (unsigned long long) _d << (i * 4); + + } + if (ds1wm_data->read_error) { + mutex_unlock(&master_dev->bus_mutex); + dev_err(&ds1wm_data->pdev->dev, + "pass: %d read error, retrying\n", pass); + break; + } + dev_dbg(&ds1wm_data->pdev->dev, + "pass: %d r\': %0#18llx d:%0#18llx\n", + pass, r_prime, d); + dev_dbg(&ds1wm_data->pdev->dev, + "pass: %d nibble loop complete, exiting ASM\n", pass); + ds1wm_write_register(ds1wm_data, DS1WM_CMD, ~DS1WM_CMD_SRA); + dev_dbg(&ds1wm_data->pdev->dev, + "pass: %d resetting bus\n", pass); + ds1wm_reset(ds1wm_data); + mutex_unlock(&master_dev->bus_mutex); + if ((r_prime & ((u64)1 << 63)) && (d & ((u64)1 << 63))) { + dev_err(&ds1wm_data->pdev->dev, + "pass: %d bus error, retrying\n", pass); + continue; /* start over */ + } + + + dev_dbg(&ds1wm_data->pdev->dev, + "pass: %d found %0#18llx\n", pass, r_prime); + slave_found(master_dev, r_prime); + ++slaves_found; + dev_dbg(&ds1wm_data->pdev->dev, + "pass: %d complete, preparing next pass\n", pass); + + /* any discrepency found which we already choose the + '1' branch is now is now irrelevant we reveal the + next branch with this: */ + d &= ~r; + /* find last bit set, i.e. the most signif. bit set */ + ms_discrep_bit = fls64(d) - 1; + dev_dbg(&ds1wm_data->pdev->dev, + "pass: %d new d:%0#18llx MS discrep bit:%d\n", + pass, d, ms_discrep_bit); + + /* prev_ms_discrep_bit = ms_discrep_bit; + prepare for next ROM search: */ + if (ms_discrep_bit == -1) + break; + + r = (r & ~(~0ull << (ms_discrep_bit))) | 1 << ms_discrep_bit; + } /* end while true */ + dev_dbg(&ds1wm_data->pdev->dev, + "pass: %d total: %d search done ms d bit pos: %d\n", pass, + slaves_found, ms_discrep_bit); +} + +/* --------------------------------------------------------------------- */ + +static struct w1_bus_master ds1wm_master = { + .read_byte = ds1wm_read_byte, + .write_byte = ds1wm_write_byte, + .reset_bus = ds1wm_reset_bus, + .search = ds1wm_search, +}; + +static int ds1wm_probe(struct platform_device *pdev) +{ + struct ds1wm_data *ds1wm_data; + struct ds1wm_driver_data *plat; + struct resource *res; + int ret; + + if (!pdev) + return -ENODEV; + + ds1wm_data = devm_kzalloc(&pdev->dev, sizeof(*ds1wm_data), GFP_KERNEL); + if (!ds1wm_data) + return -ENOMEM; + + platform_set_drvdata(pdev, ds1wm_data); + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) + return -ENXIO; + ds1wm_data->map = devm_ioremap(&pdev->dev, res->start, + resource_size(res)); + if (!ds1wm_data->map) + return -ENOMEM; + + /* calculate bus shift from mem resource */ + ds1wm_data->bus_shift = resource_size(res) >> 3; + + ds1wm_data->pdev = pdev; + ds1wm_data->cell = mfd_get_cell(pdev); + if (!ds1wm_data->cell) + return -ENODEV; + plat = dev_get_platdata(&pdev->dev); + if (!plat) + return -ENODEV; + + res = platform_get_resource(pdev, IORESOURCE_IRQ, 0); + if (!res) + return -ENXIO; + ds1wm_data->irq = res->start; + ds1wm_data->int_en_reg_none = (plat->active_high ? DS1WM_INTEN_IAS : 0); + ds1wm_data->reset_recover_delay = plat->reset_recover_delay; + + if (res->flags & IORESOURCE_IRQ_HIGHEDGE) + irq_set_irq_type(ds1wm_data->irq, IRQ_TYPE_EDGE_RISING); + if (res->flags & IORESOURCE_IRQ_LOWEDGE) + irq_set_irq_type(ds1wm_data->irq, IRQ_TYPE_EDGE_FALLING); + + ret = devm_request_irq(&pdev->dev, ds1wm_data->irq, ds1wm_isr, + IRQF_SHARED, "ds1wm", ds1wm_data); + if (ret) + return ret; + + ds1wm_up(ds1wm_data); + + ds1wm_master.data = (void *)ds1wm_data; + + ret = w1_add_master_device(&ds1wm_master); + if (ret) + goto err; + + return 0; + +err: + ds1wm_down(ds1wm_data); + + return ret; +} + +#ifdef CONFIG_PM +static int ds1wm_suspend(struct platform_device *pdev, pm_message_t state) +{ + struct ds1wm_data *ds1wm_data = platform_get_drvdata(pdev); + + ds1wm_down(ds1wm_data); + + return 0; +} + +static int ds1wm_resume(struct platform_device *pdev) +{ + struct ds1wm_data *ds1wm_data = platform_get_drvdata(pdev); + + ds1wm_up(ds1wm_data); + + return 0; +} +#else +#define ds1wm_suspend NULL +#define ds1wm_resume NULL +#endif + +static int ds1wm_remove(struct platform_device *pdev) +{ + struct ds1wm_data *ds1wm_data = platform_get_drvdata(pdev); + + w1_remove_master_device(&ds1wm_master); + ds1wm_down(ds1wm_data); + + return 0; +} + +static struct platform_driver ds1wm_driver = { + .driver = { + .name = "ds1wm", + }, + .probe = ds1wm_probe, + .remove = ds1wm_remove, + .suspend = ds1wm_suspend, + .resume = ds1wm_resume +}; + +static int __init ds1wm_init(void) +{ + pr_info("DS1WM w1 busmaster driver - (c) 2004 Szabolcs Gyurko\n"); + return platform_driver_register(&ds1wm_driver); +} + +static void __exit ds1wm_exit(void) +{ + platform_driver_unregister(&ds1wm_driver); +} + +module_init(ds1wm_init); +module_exit(ds1wm_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>, " + "Matt Reimer <mreimer@vpop.net>," + "Jean-Francois Dagenais <dagenaisj@sonatest.com>"); +MODULE_DESCRIPTION("DS1WM w1 busmaster driver"); |